From 1f29fae29709b4668979e244c09b2fa78ff1ad59 Mon Sep 17 00:00:00 2001 From: "Serge E. Hallyn" Date: Wed, 5 Nov 2008 16:08:52 -0600 Subject: file capabilities: add no_file_caps switch (v4) Add a no_file_caps boot option when file capabilities are compiled into the kernel (CONFIG_SECURITY_FILE_CAPABILITIES=y). This allows distributions to ship a kernel with file capabilities compiled in, without forcing users to use (and understand and trust) them. When no_file_caps is specified at boot, then when a process executes a file, any file capabilities stored with that file will not be used in the calculation of the process' new capability sets. This means that booting with the no_file_caps boot option will not be the same as booting a kernel with file capabilities compiled out - in particular a task with CAP_SETPCAP will not have any chance of passing capabilities to another task (which isn't "really" possible anyway, and which may soon by killed altogether by David Howells in any case), and it will instead be able to put new capabilities in its pI. However since fI will always be empty and pI is masked with fI, it gains the task nothing. We also support the extra prctl options, setting securebits and dropping capabilities from the per-process bounding set. The other remaining difference is that killpriv, task_setscheduler, setioprio, and setnice will continue to be hooked. That will be noticable in the case where a root task changed its uid while keeping some caps, and another task owned by the new uid tries to change settings for the more privileged task. Changelog: Nov 05 2008: (v4) trivial port on top of always-start-\ with-clear-caps patch Sep 23 2008: nixed file_caps_enabled when file caps are not compiled in as it isn't used. Document no_file_caps in kernel-parameters.txt. Signed-off-by: Serge Hallyn Acked-by: Andrew G. Morgan Signed-off-by: James Morris --- include/linux/capability.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/capability.h b/include/linux/capability.h index 9d1fe30b6f6c..5bc145bd759a 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -68,6 +68,9 @@ typedef struct __user_cap_data_struct { #define VFS_CAP_U32 VFS_CAP_U32_2 #define VFS_CAP_REVISION VFS_CAP_REVISION_2 +#ifdef CONFIG_SECURITY_FILE_CAPABILITIES +extern int file_caps_enabled; +#endif struct vfs_cap_data { __le32 magic_etc; /* Little endian */ -- cgit v1.2.3 From 9d36be76c55ad2c2bb29683b752b0d9ad2e4eeef Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 11 Nov 2008 21:48:07 +1100 Subject: Document the order of arguments for cap_issubset. It's not instantly clear which order the argument should be in. So give an example. Signed-off-by: Eric Paris Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/capability.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include') diff --git a/include/linux/capability.h b/include/linux/capability.h index 5bc145bd759a..b5750d0b96e0 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -457,6 +457,13 @@ static inline int cap_isclear(const kernel_cap_t a) return 1; } +/* + * Check if "a" is a subset of "set". + * return 1 if ALL of the capabilities in "a" are also in "set" + * cap_issubset(0101, 1111) will return 1 + * return 0 if ANY of the capabilities in "a" are not in "set" + * cap_issubset(1111, 0101) will return 0 + */ static inline int cap_issubset(const kernel_cap_t a, const kernel_cap_t set) { kernel_cap_t dest; -- cgit v1.2.3 From c0b004413a46a0a5744e6d2b85220fe9d2c33d48 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 11 Nov 2008 21:48:10 +1100 Subject: This patch add a generic cpu endian caps structure and externally available functions which retrieve fcaps information from disk. This information is necessary so fcaps information can be collected and recorded by the audit system. Signed-off-by: Eric Paris Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/capability.h | 7 +++ security/commoncap.c | 129 +++++++++++++++++++++++++-------------------- 2 files changed, 78 insertions(+), 58 deletions(-) (limited to 'include') diff --git a/include/linux/capability.h b/include/linux/capability.h index b5750d0b96e0..d567af247ed8 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -99,6 +99,13 @@ typedef struct kernel_cap_struct { __u32 cap[_KERNEL_CAPABILITY_U32S]; } kernel_cap_t; +/* exact same as vfs_cap_data but in cpu endian and always filled completely */ +struct cpu_vfs_cap_data { + __u32 magic_etc; + kernel_cap_t permitted; + kernel_cap_t inheritable; +}; + #define _USER_CAP_HEADER_SIZE (sizeof(struct __user_cap_header_struct)) #define _KERNEL_CAP_T_SIZE (sizeof(kernel_cap_t)) diff --git a/security/commoncap.c b/security/commoncap.c index f88119cb2bc2..d7eff5797b91 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -202,17 +202,70 @@ int cap_inode_killpriv(struct dentry *dentry) return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS); } -static inline int cap_from_disk(struct vfs_cap_data *caps, - struct linux_binprm *bprm, unsigned size) +static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, + struct linux_binprm *bprm) { + unsigned i; + int ret = 0; + + if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE) + bprm->cap_effective = true; + else + bprm->cap_effective = false; + + CAP_FOR_EACH_U32(i) { + __u32 permitted = caps->permitted.cap[i]; + __u32 inheritable = caps->inheritable.cap[i]; + + /* + * pP' = (X & fP) | (pI & fI) + */ + bprm->cap_post_exec_permitted.cap[i] = + (current->cap_bset.cap[i] & permitted) | + (current->cap_inheritable.cap[i] & inheritable); + + if (permitted & ~bprm->cap_post_exec_permitted.cap[i]) { + /* + * insufficient to execute correctly + */ + ret = -EPERM; + } + } + + /* + * For legacy apps, with no internal support for recognizing they + * do not have enough capabilities, we return an error if they are + * missing some "forced" (aka file-permitted) capabilities. + */ + return bprm->cap_effective ? ret : 0; +} + +int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps) +{ + struct inode *inode = dentry->d_inode; __u32 magic_etc; unsigned tocopy, i; - int ret; + int size; + struct vfs_cap_data caps; + + memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data)); + + if (!inode || !inode->i_op || !inode->i_op->getxattr) + return -ENODATA; + + size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps, + XATTR_CAPS_SZ); + if (size == -ENODATA || size == -EOPNOTSUPP) { + /* no data, that's ok */ + return -ENODATA; + } + if (size < 0) + return size; if (size < sizeof(magic_etc)) return -EINVAL; - magic_etc = le32_to_cpu(caps->magic_etc); + cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc); switch ((magic_etc & VFS_CAP_REVISION_MASK)) { case VFS_CAP_REVISION_1: @@ -229,46 +282,13 @@ static inline int cap_from_disk(struct vfs_cap_data *caps, return -EINVAL; } - if (magic_etc & VFS_CAP_FLAGS_EFFECTIVE) { - bprm->cap_effective = true; - } else { - bprm->cap_effective = false; - } - - ret = 0; - CAP_FOR_EACH_U32(i) { - __u32 value_cpu; - - if (i >= tocopy) { - /* - * Legacy capability sets have no upper bits - */ - bprm->cap_post_exec_permitted.cap[i] = 0; - continue; - } - /* - * pP' = (X & fP) | (pI & fI) - */ - value_cpu = le32_to_cpu(caps->data[i].permitted); - bprm->cap_post_exec_permitted.cap[i] = - (current->cap_bset.cap[i] & value_cpu) | - (current->cap_inheritable.cap[i] & - le32_to_cpu(caps->data[i].inheritable)); - if (value_cpu & ~bprm->cap_post_exec_permitted.cap[i]) { - /* - * insufficient to execute correctly - */ - ret = -EPERM; - } + if (i >= tocopy) + break; + cpu_caps->permitted.cap[i] = le32_to_cpu(caps.data[i].permitted); + cpu_caps->inheritable.cap[i] = le32_to_cpu(caps.data[i].inheritable); } - - /* - * For legacy apps, with no internal support for recognizing they - * do not have enough capabilities, we return an error if they are - * missing some "forced" (aka file-permitted) capabilities. - */ - return bprm->cap_effective ? ret : 0; + return 0; } /* Locate any VFS capabilities: */ @@ -276,8 +296,7 @@ static int get_file_caps(struct linux_binprm *bprm) { struct dentry *dentry; int rc = 0; - struct vfs_cap_data vcaps; - struct inode *inode; + struct cpu_vfs_cap_data vcaps; bprm_clear_caps(bprm); @@ -288,24 +307,18 @@ static int get_file_caps(struct linux_binprm *bprm) return 0; dentry = dget(bprm->file->f_dentry); - inode = dentry->d_inode; - if (!inode->i_op || !inode->i_op->getxattr) - goto out; - rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &vcaps, - XATTR_CAPS_SZ); - if (rc == -ENODATA || rc == -EOPNOTSUPP) { - /* no data, that's ok */ - rc = 0; + rc = get_vfs_caps_from_disk(dentry, &vcaps); + if (rc < 0) { + if (rc == -EINVAL) + printk(KERN_NOTICE "%s: get_vfs_caps_from_disk returned %d for %s\n", + __func__, rc, bprm->filename); + else if (rc == -ENODATA) + rc = 0; goto out; } - if (rc < 0) - goto out; - rc = cap_from_disk(&vcaps, bprm, rc); - if (rc == -EINVAL) - printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n", - __func__, rc, bprm->filename); + rc = bprm_caps_from_vfs_caps(&vcaps, bprm); out: dput(dentry); -- cgit v1.2.3 From 851f7ff56d9c21272f289dd85fb3f1b6cf7a6e10 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 11 Nov 2008 21:48:14 +1100 Subject: This patch will print cap_permitted and cap_inheritable data in the PATH records of any file that has file capabilities set. Files which do not have fcaps set will not have different PATH records. An example audit record if you run: setcap "cap_net_admin+pie" /bin/bash /bin/bash type=SYSCALL msg=audit(1225741937.363:230): arch=c000003e syscall=59 success=yes exit=0 a0=2119230 a1=210da30 a2=20ee290 a3=8 items=2 ppid=2149 pid=2923 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=3 comm="ping" exe="/bin/ping" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null) type=EXECVE msg=audit(1225741937.363:230): argc=2 a0="ping" a1="www.google.com" type=CWD msg=audit(1225741937.363:230): cwd="/root" type=PATH msg=audit(1225741937.363:230): item=0 name="/bin/ping" inode=49256 dev=fd:00 mode=0104755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ping_exec_t:s0 cap_fp=0000000000002000 cap_fi=0000000000002000 cap_fe=1 cap_fver=2 type=PATH msg=audit(1225741937.363:230): item=1 name=(null) inode=507915 dev=fd:00 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ld_so_t:s0 Signed-off-by: Eric Paris Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/capability.h | 5 +++ kernel/auditsc.c | 82 +++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 82 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/capability.h b/include/linux/capability.h index d567af247ed8..0f1950181102 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -53,6 +53,7 @@ typedef struct __user_cap_data_struct { #define XATTR_NAME_CAPS XATTR_SECURITY_PREFIX XATTR_CAPS_SUFFIX #define VFS_CAP_REVISION_MASK 0xFF000000 +#define VFS_CAP_REVISION_SHIFT 24 #define VFS_CAP_FLAGS_MASK ~VFS_CAP_REVISION_MASK #define VFS_CAP_FLAGS_EFFECTIVE 0x000001 @@ -534,6 +535,10 @@ kernel_cap_t cap_set_effective(const kernel_cap_t pE_new); extern int capable(int cap); +/* audit system wants to get cap info from files as well */ +struct dentry; +extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps); + #endif /* __KERNEL__ */ #endif /* !_LINUX_CAPABILITY_H */ diff --git a/kernel/auditsc.c b/kernel/auditsc.c index cf5bc2f5f9c3..de7e9bcba9ae 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -65,6 +65,7 @@ #include #include #include +#include #include "audit.h" @@ -84,6 +85,15 @@ int audit_n_rules; /* determines whether we collect data for signals sent */ int audit_signals; +struct audit_cap_data { + kernel_cap_t permitted; + kernel_cap_t inheritable; + union { + unsigned int fE; /* effective bit of a file capability */ + kernel_cap_t effective; /* effective set of a process */ + }; +}; + /* When fs/namei.c:getname() is called, we store the pointer in name and * we don't let putname() free it (instead we free all of the saved * pointers at syscall exit time). @@ -100,6 +110,8 @@ struct audit_names { gid_t gid; dev_t rdev; u32 osid; + struct audit_cap_data fcap; + unsigned int fcap_ver; }; struct audit_aux_data { @@ -1171,6 +1183,35 @@ static void audit_log_execve_info(struct audit_context *context, kfree(buf); } +static void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) +{ + int i; + + audit_log_format(ab, " %s=", prefix); + CAP_FOR_EACH_U32(i) { + audit_log_format(ab, "%08x", cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]); + } +} + +static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) +{ + kernel_cap_t *perm = &name->fcap.permitted; + kernel_cap_t *inh = &name->fcap.inheritable; + int log = 0; + + if (!cap_isclear(*perm)) { + audit_log_cap(ab, "cap_fp", perm); + log = 1; + } + if (!cap_isclear(*inh)) { + audit_log_cap(ab, "cap_fi", inh); + log = 1; + } + + if (log) + audit_log_format(ab, " cap_fe=%d cap_fver=%x", name->fcap.fE, name->fcap_ver); +} + static void audit_log_exit(struct audit_context *context, struct task_struct *tsk) { int i, call_panic = 0; @@ -1421,6 +1462,8 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts } } + audit_log_fcaps(ab, n); + audit_log_end(ab); } @@ -1787,8 +1830,36 @@ static int audit_inc_name_count(struct audit_context *context, return 0; } + +static inline int audit_copy_fcaps(struct audit_names *name, const struct dentry *dentry) +{ + struct cpu_vfs_cap_data caps; + int rc; + + memset(&name->fcap.permitted, 0, sizeof(kernel_cap_t)); + memset(&name->fcap.inheritable, 0, sizeof(kernel_cap_t)); + name->fcap.fE = 0; + name->fcap_ver = 0; + + if (!dentry) + return 0; + + rc = get_vfs_caps_from_disk(dentry, &caps); + if (rc) + return rc; + + name->fcap.permitted = caps.permitted; + name->fcap.inheritable = caps.inheritable; + name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); + name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT; + + return 0; +} + + /* Copy inode data into an audit_names. */ -static void audit_copy_inode(struct audit_names *name, const struct inode *inode) +static void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, + const struct inode *inode) { name->ino = inode->i_ino; name->dev = inode->i_sb->s_dev; @@ -1797,6 +1868,7 @@ static void audit_copy_inode(struct audit_names *name, const struct inode *inode name->gid = inode->i_gid; name->rdev = inode->i_rdev; security_inode_getsecid(inode, &name->osid); + audit_copy_fcaps(name, dentry); } /** @@ -1831,7 +1903,7 @@ void __audit_inode(const char *name, const struct dentry *dentry) context->names[idx].name = NULL; } handle_path(dentry); - audit_copy_inode(&context->names[idx], inode); + audit_copy_inode(&context->names[idx], dentry, inode); } /** @@ -1892,7 +1964,7 @@ void __audit_inode_child(const char *dname, const struct dentry *dentry, if (!strcmp(dname, n->name) || !audit_compare_dname_path(dname, n->name, &dirlen)) { if (inode) - audit_copy_inode(n, inode); + audit_copy_inode(n, NULL, inode); else n->ino = (unsigned long)-1; found_child = n->name; @@ -1906,7 +1978,7 @@ add_names: return; idx = context->name_count - 1; context->names[idx].name = NULL; - audit_copy_inode(&context->names[idx], parent); + audit_copy_inode(&context->names[idx], NULL, parent); } if (!found_child) { @@ -1927,7 +1999,7 @@ add_names: } if (inode) - audit_copy_inode(&context->names[idx], inode); + audit_copy_inode(&context->names[idx], NULL, inode); else context->names[idx].ino = (unsigned long)-1; } -- cgit v1.2.3 From 3fc689e96c0c90b6fede5946d6c31075e9464f69 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 11 Nov 2008 21:48:18 +1100 Subject: Any time fcaps or a setuid app under SECURE_NOROOT is used to result in a non-zero pE we will crate a new audit record which contains the entire set of known information about the executable in question, fP, fI, fE, fversion and includes the process's pE, pI, pP. Before and after the bprm capability are applied. This record type will only be emitted from execve syscalls. an example of making ping use fcaps instead of setuid: setcap "cat_net_raw+pe" /bin/ping type=SYSCALL msg=audit(1225742021.015:236): arch=c000003e syscall=59 success=yes exit=0 a0=1457f30 a1=14606b0 a2=1463940 a3=321b770a70 items=2 ppid=2929 pid=2963 auid=0 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=pts0 ses=3 comm="ping" exe="/bin/ping" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null) type=UNKNOWN[1321] msg=audit(1225742021.015:236): fver=2 fp=0000000000002000 fi=0000000000000000 fe=1 old_pp=0000000000000000 old_pi=0000000000000000 old_pe=0000000000000000 new_pp=0000000000002000 new_pi=0000000000000000 new_pe=0000000000002000 type=EXECVE msg=audit(1225742021.015:236): argc=2 a0="ping" a1="127.0.0.1" type=CWD msg=audit(1225742021.015:236): cwd="/home/test" type=PATH msg=audit(1225742021.015:236): item=0 name="/bin/ping" inode=49256 dev=fd:00 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ping_exec_t:s0 cap_fp=0000000000002000 cap_fe=1 cap_fver=2 type=PATH msg=audit(1225742021.015:236): item=1 name=(null) inode=507915 dev=fd:00 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ld_so_t:s0 Signed-off-by: Eric Paris Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/audit.h | 26 ++++++++++++++++++++ kernel/auditsc.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++ security/commoncap.c | 23 ++++++++++++++++- 3 files changed, 116 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/audit.h b/include/linux/audit.h index 6272a395d43c..8cfb9feb2a05 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -99,6 +99,7 @@ #define AUDIT_OBJ_PID 1318 /* ptrace target */ #define AUDIT_TTY 1319 /* Input on an administrative TTY */ #define AUDIT_EOE 1320 /* End of multi-record event */ +#define AUDIT_BPRM_FCAPS 1321 /* Information about fcaps increasing perms */ #define AUDIT_AVC 1400 /* SE Linux avc denial or grant */ #define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */ @@ -452,6 +453,7 @@ extern int __audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_pr extern int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len, unsigned int __user *u_msg_prio, const struct timespec __user *u_abs_timeout); extern int __audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification); extern int __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat); +extern void __audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_cap_t *pE); static inline int audit_ipc_obj(struct kern_ipc_perm *ipcp) { @@ -501,6 +503,29 @@ static inline int audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat) return __audit_mq_getsetattr(mqdes, mqstat); return 0; } + +/* + * ieieeeeee, an audit function without a return code! + * + * This function might fail! I decided that it didn't matter. We are too late + * to fail the syscall and the information isn't REQUIRED for any purpose. It's + * just nice to have. We should be able to look at past audit logs to figure + * out this process's current cap set along with the fcaps from the PATH record + * and use that to come up with the final set. Yeah, its ugly, but all the info + * is still in the audit log. So I'm not going to bother mentioning we failed + * if we couldn't allocate memory. + * + * If someone changes their mind they could create the aux record earlier and + * then search here and use that earlier allocation. But I don't wanna. + * + * -Eric + */ +static inline void audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_cap_t *pE) +{ + if (unlikely(!audit_dummy_context())) + __audit_log_bprm_fcaps(bprm, pP, pE); +} + extern int audit_n_rules; extern int audit_signals; #else @@ -532,6 +557,7 @@ extern int audit_signals; #define audit_mq_timedreceive(d,l,p,t) ({ 0; }) #define audit_mq_notify(d,n) ({ 0; }) #define audit_mq_getsetattr(d,s) ({ 0; }) +#define audit_log_bprm_fcaps(b, p, e) do { ; } while (0) #define audit_ptrace(t) ((void)0) #define audit_n_rules 0 #define audit_signals 0 diff --git a/kernel/auditsc.c b/kernel/auditsc.c index de7e9bcba9ae..3229cd4206f5 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -196,6 +196,14 @@ struct audit_aux_data_pids { int pid_count; }; +struct audit_aux_data_bprm_fcaps { + struct audit_aux_data d; + struct audit_cap_data fcap; + unsigned int fcap_ver; + struct audit_cap_data old_pcap; + struct audit_cap_data new_pcap; +}; + struct audit_tree_refs { struct audit_tree_refs *next; struct audit_chunk *c[31]; @@ -1375,6 +1383,20 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts audit_log_format(ab, "fd0=%d fd1=%d", axs->fd[0], axs->fd[1]); break; } + case AUDIT_BPRM_FCAPS: { + struct audit_aux_data_bprm_fcaps *axs = (void *)aux; + audit_log_format(ab, "fver=%x", axs->fcap_ver); + audit_log_cap(ab, "fp", &axs->fcap.permitted); + audit_log_cap(ab, "fi", &axs->fcap.inheritable); + audit_log_format(ab, " fe=%d", axs->fcap.fE); + audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted); + audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable); + audit_log_cap(ab, "old_pe", &axs->old_pcap.effective); + audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted); + audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable); + audit_log_cap(ab, "new_pe", &axs->new_pcap.effective); + break; } + } audit_log_end(ab); } @@ -2501,6 +2523,52 @@ int __audit_signal_info(int sig, struct task_struct *t) return 0; } +/** + * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps + * @bprm pointer to the bprm being processed + * @caps the caps read from the disk + * + * Simply check if the proc already has the caps given by the file and if not + * store the priv escalation info for later auditing at the end of the syscall + * + * this can fail and we don't care. See the note in audit.h for + * audit_log_bprm_fcaps() for my explaination.... + * + * -Eric + */ +void __audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_cap_t *pE) +{ + struct audit_aux_data_bprm_fcaps *ax; + struct audit_context *context = current->audit_context; + struct cpu_vfs_cap_data vcaps; + struct dentry *dentry; + + ax = kmalloc(sizeof(*ax), GFP_KERNEL); + if (!ax) + return; + + ax->d.type = AUDIT_BPRM_FCAPS; + ax->d.next = context->aux; + context->aux = (void *)ax; + + dentry = dget(bprm->file->f_dentry); + get_vfs_caps_from_disk(dentry, &vcaps); + dput(dentry); + + ax->fcap.permitted = vcaps.permitted; + ax->fcap.inheritable = vcaps.inheritable; + ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); + ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT; + + ax->old_pcap.permitted = *pP; + ax->old_pcap.inheritable = current->cap_inheritable; + ax->old_pcap.effective = *pE; + + ax->new_pcap.permitted = current->cap_permitted; + ax->new_pcap.inheritable = current->cap_inheritable; + ax->new_pcap.effective = current->cap_effective; +} + /** * audit_core_dumps - record information about processes that end abnormally * @signr: signal value diff --git a/security/commoncap.c b/security/commoncap.c index d7eff5797b91..d45393380997 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -8,6 +8,7 @@ */ #include +#include #include #include #include @@ -376,6 +377,9 @@ int cap_bprm_set_security (struct linux_binprm *bprm) void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) { + kernel_cap_t pP = current->cap_permitted; + kernel_cap_t pE = current->cap_effective; + if (bprm->e_uid != current->uid || bprm->e_gid != current->gid || !cap_issubset(bprm->cap_post_exec_permitted, current->cap_permitted)) { @@ -409,7 +413,24 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) cap_clear(current->cap_effective); } - /* AUD: Audit candidate if current->cap_effective is set */ + /* + * Audit candidate if current->cap_effective is set + * + * We do not bother to audit if 3 things are true: + * 1) cap_effective has all caps + * 2) we are root + * 3) root is supposed to have all caps (SECURE_NOROOT) + * Since this is just a normal root execing a process. + * + * Number 1 above might fail if you don't have a full bset, but I think + * that is interesting information to audit. + */ + if (!cap_isclear(current->cap_effective)) { + if (!cap_issubset(CAP_FULL_SET, current->cap_effective) || + (bprm->e_uid != 0) || (current->uid != 0) || + issecure(SECURE_NOROOT)) + audit_log_bprm_fcaps(bprm, &pP, &pE); + } current->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); } -- cgit v1.2.3 From e68b75a027bb94066576139ee33676264f867b87 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 11 Nov 2008 21:48:22 +1100 Subject: When the capset syscall is used it is not possible for audit to record the actual capbilities being added/removed. This patch adds a new record type which emits the target pid and the eff, inh, and perm cap sets. example output if you audit capset syscalls would be: type=SYSCALL msg=audit(1225743140.465:76): arch=c000003e syscall=126 success=yes exit=0 a0=17f2014 a1=17f201c a2=80000000 a3=7fff2ab7f060 items=0 ppid=2160 pid=2223 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=1 comm="setcap" exe="/usr/sbin/setcap" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null) type=UNKNOWN[1322] msg=audit(1225743140.465:76): pid=0 cap_pi=ffffffffffffffff cap_pp=ffffffffffffffff cap_pe=ffffffffffffffff Signed-off-by: Eric Paris Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/audit.h | 10 ++++++++++ kernel/auditsc.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ kernel/capability.c | 5 +++++ 3 files changed, 63 insertions(+) (limited to 'include') diff --git a/include/linux/audit.h b/include/linux/audit.h index 8cfb9feb2a05..6fbebac7b1bf 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -100,6 +100,7 @@ #define AUDIT_TTY 1319 /* Input on an administrative TTY */ #define AUDIT_EOE 1320 /* End of multi-record event */ #define AUDIT_BPRM_FCAPS 1321 /* Information about fcaps increasing perms */ +#define AUDIT_CAPSET 1322 /* Record showing argument to sys_capset */ #define AUDIT_AVC 1400 /* SE Linux avc denial or grant */ #define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */ @@ -454,6 +455,7 @@ extern int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len, unsigned int __u extern int __audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification); extern int __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat); extern void __audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_cap_t *pE); +extern int __audit_log_capset(pid_t pid, kernel_cap_t *eff, kernel_cap_t *inh, kernel_cap_t *perm); static inline int audit_ipc_obj(struct kern_ipc_perm *ipcp) { @@ -526,6 +528,13 @@ static inline void audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t __audit_log_bprm_fcaps(bprm, pP, pE); } +static inline int audit_log_capset(pid_t pid, kernel_cap_t *eff, kernel_cap_t *inh, kernel_cap_t *perm) +{ + if (unlikely(!audit_dummy_context())) + return __audit_log_capset(pid, eff, inh, perm); + return 0; +} + extern int audit_n_rules; extern int audit_signals; #else @@ -558,6 +567,7 @@ extern int audit_signals; #define audit_mq_notify(d,n) ({ 0; }) #define audit_mq_getsetattr(d,s) ({ 0; }) #define audit_log_bprm_fcaps(b, p, e) do { ; } while (0) +#define audit_log_capset(pid, e, i, p) ({ 0; }) #define audit_ptrace(t) ((void)0) #define audit_n_rules 0 #define audit_signals 0 diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 3229cd4206f5..cef34235b362 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -204,6 +204,12 @@ struct audit_aux_data_bprm_fcaps { struct audit_cap_data new_pcap; }; +struct audit_aux_data_capset { + struct audit_aux_data d; + pid_t pid; + struct audit_cap_data cap; +}; + struct audit_tree_refs { struct audit_tree_refs *next; struct audit_chunk *c[31]; @@ -1397,6 +1403,14 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts audit_log_cap(ab, "new_pe", &axs->new_pcap.effective); break; } + case AUDIT_CAPSET: { + struct audit_aux_data_capset *axs = (void *)aux; + audit_log_format(ab, "pid=%d", axs->pid); + audit_log_cap(ab, "cap_pi", &axs->cap.inheritable); + audit_log_cap(ab, "cap_pp", &axs->cap.permitted); + audit_log_cap(ab, "cap_pe", &axs->cap.effective); + break; } + } audit_log_end(ab); } @@ -2569,6 +2583,40 @@ void __audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_ ax->new_pcap.effective = current->cap_effective; } +/** + * __audit_log_capset - store information about the arguments to the capset syscall + * @pid target pid of the capset call + * @eff effective cap set + * @inh inheritible cap set + * @perm permited cap set + * + * Record the aguments userspace sent to sys_capset for later printing by the + * audit system if applicable + */ +int __audit_log_capset(pid_t pid, kernel_cap_t *eff, kernel_cap_t *inh, kernel_cap_t *perm) +{ + struct audit_aux_data_capset *ax; + struct audit_context *context = current->audit_context; + + if (likely(!audit_enabled || !context || context->dummy)) + return 0; + + ax = kmalloc(sizeof(*ax), GFP_KERNEL); + if (!ax) + return -ENOMEM; + + ax->d.type = AUDIT_CAPSET; + ax->d.next = context->aux; + context->aux = (void *)ax; + + ax->pid = pid; + ax->cap.effective = *eff; + ax->cap.inheritable = *eff; + ax->cap.permitted = *perm; + + return 0; +} + /** * audit_core_dumps - record information about processes that end abnormally * @signr: signal value diff --git a/kernel/capability.c b/kernel/capability.c index e13a68535ad5..19f9eda89975 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -7,6 +7,7 @@ * 30 May 2002: Cleanup, Robert M. Love */ +#include #include #include #include @@ -468,6 +469,10 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) i++; } + ret = audit_log_capset(pid, &effective, &inheritable, &permitted); + if (ret) + return ret; + if (pid && (pid != task_pid_vnr(current))) ret = do_sys_capset_other_tasks(pid, &effective, &inheritable, &permitted); -- cgit v1.2.3 From 06112163f5fd9e491a7f810443d81efa9d88e247 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 11 Nov 2008 22:02:50 +1100 Subject: Add a new capable interface that will be used by systems that use audit to make an A or B type decision instead of a security decision. Currently this is the case at least for filesystems when deciding if a process can use the reserved 'root' blocks and for the case of things like the oom algorithm determining if processes are root processes and should be less likely to be killed. These types of security system requests should not be audited or logged since they are not really security decisions. It would be possible to solve this problem like the vm_enough_memory security check did by creating a new LSM interface and moving all of the policy into that interface but proves the needlessly bloat the LSM and provide complex indirection. This merely allows those decisions to be made where they belong and to not flood logs or printk with denials for thing that are not security decisions. Signed-off-by: Eric Paris Acked-by: Stephen Smalley Signed-off-by: James Morris --- include/linux/capability.h | 3 +++ include/linux/security.h | 16 +++++++++++++--- security/commoncap.c | 8 ++++---- security/security.c | 7 ++++++- security/selinux/hooks.c | 20 +++++++++++++------- 5 files changed, 39 insertions(+), 15 deletions(-) (limited to 'include') diff --git a/include/linux/capability.h b/include/linux/capability.h index 0f1950181102..b313ba1dd5d1 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -521,6 +521,8 @@ extern const kernel_cap_t __cap_init_eff_set; kernel_cap_t cap_set_effective(const kernel_cap_t pE_new); +extern int security_capable(struct task_struct *t, int cap); +extern int security_capable_noaudit(struct task_struct *t, int cap); /** * has_capability - Determine if a task has a superior capability available * @t: The task in question @@ -532,6 +534,7 @@ kernel_cap_t cap_set_effective(const kernel_cap_t pE_new); * Note that this does not set PF_SUPERPRIV on the task. */ #define has_capability(t, cap) (security_capable((t), (cap)) == 0) +#define has_capability_noaudit(t, cap) (security_capable_noaudit((t), (cap)) == 0) extern int capable(int cap); diff --git a/include/linux/security.h b/include/linux/security.h index c13f1cec9abb..5fe28a671cd3 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -37,6 +37,10 @@ /* Maximum number of letters for an LSM name string */ #define SECURITY_NAME_MAX 10 +/* If capable should audit the security request */ +#define SECURITY_CAP_NOAUDIT 0 +#define SECURITY_CAP_AUDIT 1 + struct ctl_table; struct audit_krule; @@ -44,7 +48,7 @@ struct audit_krule; * These functions are in security/capability.c and are used * as the default capabilities functions */ -extern int cap_capable(struct task_struct *tsk, int cap); +extern int cap_capable(struct task_struct *tsk, int cap, int audit); extern int cap_settime(struct timespec *ts, struct timezone *tz); extern int cap_ptrace_may_access(struct task_struct *child, unsigned int mode); extern int cap_ptrace_traceme(struct task_struct *parent); @@ -1307,7 +1311,7 @@ struct security_operations { kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); - int (*capable) (struct task_struct *tsk, int cap); + int (*capable) (struct task_struct *tsk, int cap, int audit); int (*acct) (struct file *file); int (*sysctl) (struct ctl_table *table, int op); int (*quotactl) (int cmds, int type, int id, struct super_block *sb); @@ -1577,6 +1581,7 @@ void security_capset_set(struct task_struct *target, kernel_cap_t *inheritable, kernel_cap_t *permitted); int security_capable(struct task_struct *tsk, int cap); +int security_capable_noaudit(struct task_struct *tsk, int cap); int security_acct(struct file *file); int security_sysctl(struct ctl_table *table, int op); int security_quotactl(int cmds, int type, int id, struct super_block *sb); @@ -1782,7 +1787,12 @@ static inline void security_capset_set(struct task_struct *target, static inline int security_capable(struct task_struct *tsk, int cap) { - return cap_capable(tsk, cap); + return cap_capable(tsk, cap, SECURITY_CAP_AUDIT); +} + +static inline int security_capable_noaudit(struct task_struct *tsk, int cap) +{ + return cap_capable(tsk, cap, SECURITY_CAP_NOAUDIT); } static inline int security_acct(struct file *file) diff --git a/security/commoncap.c b/security/commoncap.c index d45393380997..dc06c0086b55 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -49,7 +49,7 @@ EXPORT_SYMBOL(cap_netlink_recv); * returns 0 when a task has a capability, but the kernel's capable() * returns 1 for this case. */ -int cap_capable (struct task_struct *tsk, int cap) +int cap_capable(struct task_struct *tsk, int cap, int audit) { /* Derived from include/linux/sched.h:capable. */ if (cap_raised(tsk->cap_effective, cap)) @@ -112,7 +112,7 @@ static inline int cap_inh_is_capped(void) * to the old permitted set. That is, if the current task * does *not* possess the CAP_SETPCAP capability. */ - return (cap_capable(current, CAP_SETPCAP) != 0); + return (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0); } static inline int cap_limit_ptraced_target(void) { return 1; } @@ -677,7 +677,7 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, || ((current->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ - || (cap_capable(current, CAP_SETPCAP) != 0)) { /*[4]*/ + || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0)) { /*[4]*/ /* * [1] no changing of bits that are locked * [2] no unlocking of locks @@ -742,7 +742,7 @@ int cap_vm_enough_memory(struct mm_struct *mm, long pages) { int cap_sys_admin = 0; - if (cap_capable(current, CAP_SYS_ADMIN) == 0) + if (cap_capable(current, CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT) == 0) cap_sys_admin = 1; return __vm_enough_memory(mm, pages, cap_sys_admin); } diff --git a/security/security.c b/security/security.c index c0acfa7177e5..346f21e0ec2c 100644 --- a/security/security.c +++ b/security/security.c @@ -163,7 +163,12 @@ void security_capset_set(struct task_struct *target, int security_capable(struct task_struct *tsk, int cap) { - return security_ops->capable(tsk, cap); + return security_ops->capable(tsk, cap, SECURITY_CAP_AUDIT); +} + +int security_capable_noaudit(struct task_struct *tsk, int cap) +{ + return security_ops->capable(tsk, cap, SECURITY_CAP_NOAUDIT); } int security_acct(struct file *file) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 7fd4de46b2a9..88a3ee33068a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1365,12 +1365,14 @@ static int task_has_perm(struct task_struct *tsk1, /* Check whether a task is allowed to use a capability. */ static int task_has_capability(struct task_struct *tsk, - int cap) + int cap, int audit) { struct task_security_struct *tsec; struct avc_audit_data ad; + struct av_decision avd; u16 sclass; u32 av = CAP_TO_MASK(cap); + int rc; tsec = tsk->security; @@ -1390,7 +1392,11 @@ static int task_has_capability(struct task_struct *tsk, "SELinux: out of range capability %d\n", cap); BUG(); } - return avc_has_perm(tsec->sid, tsec->sid, sclass, av, &ad); + + rc = avc_has_perm_noaudit(tsec->sid, tsec->sid, sclass, av, 0, &avd); + if (audit == SECURITY_CAP_AUDIT) + avc_audit(tsec->sid, tsec->sid, sclass, av, &avd, rc, &ad); + return rc; } /* Check whether a task is allowed to use a system operation. */ @@ -1802,15 +1808,15 @@ static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effecti secondary_ops->capset_set(target, effective, inheritable, permitted); } -static int selinux_capable(struct task_struct *tsk, int cap) +static int selinux_capable(struct task_struct *tsk, int cap, int audit) { int rc; - rc = secondary_ops->capable(tsk, cap); + rc = secondary_ops->capable(tsk, cap, audit); if (rc) return rc; - return task_has_capability(tsk, cap); + return task_has_capability(tsk, cap, audit); } static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid) @@ -1975,7 +1981,7 @@ static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) int rc, cap_sys_admin = 0; struct task_security_struct *tsec = current->security; - rc = secondary_ops->capable(current, CAP_SYS_ADMIN); + rc = secondary_ops->capable(current, CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT); if (rc == 0) rc = avc_has_perm_noaudit(tsec->sid, tsec->sid, SECCLASS_CAPABILITY, @@ -2829,7 +2835,7 @@ static int selinux_inode_getsecurity(const struct inode *inode, const char *name * and lack of permission just means that we fall back to the * in-core context value, not a denial. */ - error = secondary_ops->capable(current, CAP_MAC_ADMIN); + error = secondary_ops->capable(current, CAP_MAC_ADMIN, SECURITY_CAP_NOAUDIT); if (!error) error = avc_has_perm_noaudit(tsec->sid, tsec->sid, SECCLASS_CAPABILITY2, -- cgit v1.2.3 From 92a77aac9812d5397abbe6f1920e085e50838635 Mon Sep 17 00:00:00 2001 From: James Morris Date: Wed, 12 Nov 2008 21:20:00 +1100 Subject: security: remove broken and useless declarations Remove broken declarations for security_capable* functions, which were not needed anyway. Signed-off-by: James Morris --- include/linux/capability.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include') diff --git a/include/linux/capability.h b/include/linux/capability.h index b313ba1dd5d1..7f26580a5a4d 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -521,8 +521,6 @@ extern const kernel_cap_t __cap_init_eff_set; kernel_cap_t cap_set_effective(const kernel_cap_t pE_new); -extern int security_capable(struct task_struct *t, int cap); -extern int security_capable_noaudit(struct task_struct *t, int cap); /** * has_capability - Determine if a task has a superior capability available * @t: The task in question -- cgit v1.2.3 From da9592edebceeba1b9301beafe80ec8b9c2db0ce Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:05 +1100 Subject: CRED: Wrap task credential accesses in the filesystem subsystem Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells Reviewed-by: James Morris Acked-by: Serge Hallyn Cc: Al Viro Signed-off-by: James Morris --- fs/anon_inodes.c | 4 ++-- fs/attr.c | 4 ++-- fs/binfmt_elf_fdpic.c | 8 ++++---- fs/dquot.c | 4 ++-- fs/exec.c | 18 +++++++++--------- fs/fcntl.c | 2 +- fs/inotify_user.c | 2 +- fs/ioprio.c | 4 ++-- fs/locks.c | 2 +- fs/namei.c | 10 ++++++---- fs/namespace.c | 2 +- fs/pipe.c | 4 ++-- fs/posix_acl.c | 4 ++-- fs/quota.c | 4 ++-- include/linux/fs.h | 2 +- 15 files changed, 38 insertions(+), 36 deletions(-) (limited to 'include') diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index 3662dd44896b..c16d9be1b017 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -154,8 +154,8 @@ static struct inode *anon_inode_mkinode(void) */ inode->i_state = I_DIRTY; inode->i_mode = S_IRUSR | S_IWUSR; - inode->i_uid = current->fsuid; - inode->i_gid = current->fsgid; + inode->i_uid = current_fsuid(); + inode->i_gid = current_fsgid(); inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; return inode; } diff --git a/fs/attr.c b/fs/attr.c index 7a83819f6ba2..f4360192a938 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -29,13 +29,13 @@ int inode_change_ok(struct inode *inode, struct iattr *attr) /* Make sure a caller can chown. */ if ((ia_valid & ATTR_UID) && - (current->fsuid != inode->i_uid || + (current_fsuid() != inode->i_uid || attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN)) goto error; /* Make sure caller can chgrp. */ if ((ia_valid & ATTR_GID) && - (current->fsuid != inode->i_uid || + (current_fsuid() != inode->i_uid || (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) && !capable(CAP_CHOWN)) goto error; diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 5b5424cb3391..488584c87512 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -623,10 +623,10 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); NEW_AUX_ENT(AT_FLAGS, 0); NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); - NEW_AUX_ENT(AT_UID, (elf_addr_t) current->uid); - NEW_AUX_ENT(AT_EUID, (elf_addr_t) current->euid); - NEW_AUX_ENT(AT_GID, (elf_addr_t) current->gid); - NEW_AUX_ENT(AT_EGID, (elf_addr_t) current->egid); + NEW_AUX_ENT(AT_UID, (elf_addr_t) current_uid()); + NEW_AUX_ENT(AT_EUID, (elf_addr_t) current_euid()); + NEW_AUX_ENT(AT_GID, (elf_addr_t) current_gid()); + NEW_AUX_ENT(AT_EGID, (elf_addr_t) current_egid()); NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); NEW_AUX_ENT(AT_EXECFN, bprm->exec); diff --git a/fs/dquot.c b/fs/dquot.c index 5e95261005b2..c237ccc8581c 100644 --- a/fs/dquot.c +++ b/fs/dquot.c @@ -874,7 +874,7 @@ static inline int need_print_warning(struct dquot *dquot) switch (dquot->dq_type) { case USRQUOTA: - return current->fsuid == dquot->dq_id; + return current_fsuid() == dquot->dq_id; case GRPQUOTA: return in_group_p(dquot->dq_id); } @@ -981,7 +981,7 @@ static void send_warning(const struct dquot *dquot, const char warntype) MINOR(dquot->dq_sb->s_dev)); if (ret) goto attr_err_out; - ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current->user->uid); + ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid()); if (ret) goto attr_err_out; genlmsg_end(skb, msg_head); diff --git a/fs/exec.c b/fs/exec.c index 4e834f16d9da..604834f3b208 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -980,7 +980,7 @@ int flush_old_exec(struct linux_binprm * bprm) /* This is the point of no return */ current->sas_ss_sp = current->sas_ss_size = 0; - if (current->euid == current->uid && current->egid == current->gid) + if (current_euid() == current_uid() && current_egid() == current_gid()) set_dumpable(current->mm, 1); else set_dumpable(current->mm, suid_dumpable); @@ -1007,7 +1007,7 @@ int flush_old_exec(struct linux_binprm * bprm) */ current->mm->task_size = TASK_SIZE; - if (bprm->e_uid != current->euid || bprm->e_gid != current->egid) { + if (bprm->e_uid != current_euid() || bprm->e_gid != current_egid()) { suid_keys(current); set_dumpable(current->mm, suid_dumpable); current->pdeath_signal = 0; @@ -1047,8 +1047,8 @@ int prepare_binprm(struct linux_binprm *bprm) if (bprm->file->f_op == NULL) return -EACCES; - bprm->e_uid = current->euid; - bprm->e_gid = current->egid; + bprm->e_uid = current_euid(); + bprm->e_gid = current_egid(); if(!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { /* Set-uid? */ @@ -1096,7 +1096,7 @@ void compute_creds(struct linux_binprm *bprm) { int unsafe; - if (bprm->e_uid != current->uid) { + if (bprm->e_uid != current_uid()) { suid_keys(current); current->pdeath_signal = 0; } @@ -1424,7 +1424,7 @@ static int format_corename(char *corename, long signr) /* uid */ case 'u': rc = snprintf(out_ptr, out_end - out_ptr, - "%d", current->uid); + "%d", current_uid()); if (rc > out_end - out_ptr) goto out; out_ptr += rc; @@ -1432,7 +1432,7 @@ static int format_corename(char *corename, long signr) /* gid */ case 'g': rc = snprintf(out_ptr, out_end - out_ptr, - "%d", current->gid); + "%d", current_gid()); if (rc > out_end - out_ptr) goto out; out_ptr += rc; @@ -1709,7 +1709,7 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs) struct inode * inode; struct file * file; int retval = 0; - int fsuid = current->fsuid; + int fsuid = current_fsuid(); int flag = 0; int ispipe = 0; unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur; @@ -1815,7 +1815,7 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs) * Dont allow local users get cute and trick others to coredump * into their pre-created files: */ - if (inode->i_uid != current->fsuid) + if (inode->i_uid != current_fsuid()) goto close_fail; if (!file->f_op) goto close_fail; diff --git a/fs/fcntl.c b/fs/fcntl.c index ac4f7db9f134..bf049a805e59 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -211,7 +211,7 @@ int __f_setown(struct file *filp, struct pid *pid, enum pid_type type, if (err) return err; - f_modown(filp, pid, type, current->uid, current->euid, force); + f_modown(filp, pid, type, current_uid(), current_euid(), force); return 0; } EXPORT_SYMBOL(__f_setown); diff --git a/fs/inotify_user.c b/fs/inotify_user.c index d367e9b92862..e2425bbd871f 100644 --- a/fs/inotify_user.c +++ b/fs/inotify_user.c @@ -601,7 +601,7 @@ asmlinkage long sys_inotify_init1(int flags) goto out_put_fd; } - user = get_uid(current->user); + user = get_current_user(); if (unlikely(atomic_read(&user->inotify_devs) >= inotify_max_user_instances)) { ret = -EMFILE; diff --git a/fs/ioprio.c b/fs/ioprio.c index da3cc460d4df..68d2cd807118 100644 --- a/fs/ioprio.c +++ b/fs/ioprio.c @@ -32,8 +32,8 @@ static int set_task_ioprio(struct task_struct *task, int ioprio) int err; struct io_context *ioc; - if (task->uid != current->euid && - task->uid != current->uid && !capable(CAP_SYS_NICE)) + if (task->uid != current_euid() && + task->uid != current_uid() && !capable(CAP_SYS_NICE)) return -EPERM; err = security_task_setioprio(task, ioprio); diff --git a/fs/locks.c b/fs/locks.c index 09062e3ff104..46a2e12f7d42 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1349,7 +1349,7 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp) struct inode *inode = dentry->d_inode; int error, rdlease_count = 0, wrlease_count = 0; - if ((current->fsuid != inode->i_uid) && !capable(CAP_LEASE)) + if ((current_fsuid() != inode->i_uid) && !capable(CAP_LEASE)) return -EACCES; if (!S_ISREG(inode->i_mode)) return -EINVAL; diff --git a/fs/namei.c b/fs/namei.c index 09ce58e49e72..42d7b7606936 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -186,7 +186,7 @@ int generic_permission(struct inode *inode, int mask, mask &= MAY_READ | MAY_WRITE | MAY_EXEC; - if (current->fsuid == inode->i_uid) + if (current_fsuid() == inode->i_uid) mode >>= 6; else { if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) { @@ -441,7 +441,7 @@ static int exec_permission_lite(struct inode *inode) if (inode->i_op && inode->i_op->permission) return -EAGAIN; - if (current->fsuid == inode->i_uid) + if (current_fsuid() == inode->i_uid) mode >>= 6; else if (in_group_p(inode->i_gid)) mode >>= 3; @@ -1334,11 +1334,13 @@ static int user_path_parent(int dfd, const char __user *path, */ static inline int check_sticky(struct inode *dir, struct inode *inode) { + uid_t fsuid = current_fsuid(); + if (!(dir->i_mode & S_ISVTX)) return 0; - if (inode->i_uid == current->fsuid) + if (inode->i_uid == fsuid) return 0; - if (dir->i_uid == current->fsuid) + if (dir->i_uid == fsuid) return 0; return !capable(CAP_FOWNER); } diff --git a/fs/namespace.c b/fs/namespace.c index cce46702d33c..d8bc2c4704a5 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1176,7 +1176,7 @@ static int mount_is_safe(struct path *path) if (S_ISLNK(path->dentry->d_inode->i_mode)) return -EPERM; if (path->dentry->d_inode->i_mode & S_ISVTX) { - if (current->uid != path->dentry->d_inode->i_uid) + if (current_uid() != path->dentry->d_inode->i_uid) return -EPERM; } if (inode_permission(path->dentry->d_inode, MAY_WRITE)) diff --git a/fs/pipe.c b/fs/pipe.c index 7aea8b89baac..aaf797bd57b9 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -899,8 +899,8 @@ static struct inode * get_pipe_inode(void) */ inode->i_state = I_DIRTY; inode->i_mode = S_IFIFO | S_IRUSR | S_IWUSR; - inode->i_uid = current->fsuid; - inode->i_gid = current->fsgid; + inode->i_uid = current_fsuid(); + inode->i_gid = current_fsgid(); inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; return inode; diff --git a/fs/posix_acl.c b/fs/posix_acl.c index aec931e09973..39df95a0ec25 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -217,11 +217,11 @@ posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want) switch(pa->e_tag) { case ACL_USER_OBJ: /* (May have been checked already) */ - if (inode->i_uid == current->fsuid) + if (inode->i_uid == current_fsuid()) goto check_perm; break; case ACL_USER: - if (pa->e_id == current->fsuid) + if (pa->e_id == current_fsuid()) goto mask; break; case ACL_GROUP_OBJ: diff --git a/fs/quota.c b/fs/quota.c index 7f4386ebc23a..b7fe44e01618 100644 --- a/fs/quota.c +++ b/fs/quota.c @@ -79,7 +79,7 @@ static int generic_quotactl_valid(struct super_block *sb, int type, int cmd, qid /* Check privileges */ if (cmd == Q_GETQUOTA) { - if (((type == USRQUOTA && current->euid != id) || + if (((type == USRQUOTA && current_euid() != id) || (type == GRPQUOTA && !in_egroup_p(id))) && !capable(CAP_SYS_ADMIN)) return -EPERM; @@ -130,7 +130,7 @@ static int xqm_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t i /* Check privileges */ if (cmd == Q_XGETQUOTA) { - if (((type == XQM_USRQUOTA && current->euid != id) || + if (((type == XQM_USRQUOTA && current_euid() != id) || (type == XQM_GRPQUOTA && !in_egroup_p(id))) && !capable(CAP_SYS_ADMIN)) return -EPERM; diff --git a/include/linux/fs.h b/include/linux/fs.h index 0dcdd9458f4b..b3d404aaabed 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1193,7 +1193,7 @@ enum { #define has_fs_excl() atomic_read(¤t->fs_excl) #define is_owner_or_cap(inode) \ - ((current->fsuid == (inode)->i_uid) || capable(CAP_FOWNER)) + ((current_fsuid() == (inode)->i_uid) || capable(CAP_FOWNER)) /* not quite ready to be deprecated, but... */ extern void lock_super(struct super_block *); -- cgit v1.2.3 From 8192b0c482d7078fcdcb4854341b977426f6f09b Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:10 +1100 Subject: CRED: Wrap task credential accesses in the networking subsystem Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells Reviewed-by: James Morris Acked-by: Serge Hallyn Cc: netdev@vger.kernel.org Signed-off-by: James Morris --- include/net/scm.h | 4 ++-- net/core/dev.c | 8 ++++++-- net/core/scm.c | 8 ++++---- net/socket.c | 4 ++-- 4 files changed, 14 insertions(+), 10 deletions(-) (limited to 'include') diff --git a/include/net/scm.h b/include/net/scm.h index 06df126103ca..f160116db54a 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -54,8 +54,8 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) { struct task_struct *p = current; - scm->creds.uid = p->uid; - scm->creds.gid = p->gid; + scm->creds.uid = current_uid(); + scm->creds.gid = current_gid(); scm->creds.pid = task_tgid_vnr(p); scm->fp = NULL; scm->seq = 0; diff --git a/net/core/dev.c b/net/core/dev.c index d9038e328cc1..262df226b3c9 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2958,6 +2958,8 @@ static void dev_change_rx_flags(struct net_device *dev, int flags) static int __dev_set_promiscuity(struct net_device *dev, int inc) { unsigned short old_flags = dev->flags; + uid_t uid; + gid_t gid; ASSERT_RTNL(); @@ -2982,15 +2984,17 @@ static int __dev_set_promiscuity(struct net_device *dev, int inc) printk(KERN_INFO "device %s %s promiscuous mode\n", dev->name, (dev->flags & IFF_PROMISC) ? "entered" : "left"); - if (audit_enabled) + if (audit_enabled) { + current_uid_gid(&uid, &gid); audit_log(current->audit_context, GFP_ATOMIC, AUDIT_ANOM_PROMISCUOUS, "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u", dev->name, (dev->flags & IFF_PROMISC), (old_flags & IFF_PROMISC), audit_get_loginuid(current), - current->uid, current->gid, + uid, gid, audit_get_sessionid(current)); + } dev_change_rx_flags(dev, IFF_PROMISC); } diff --git a/net/core/scm.c b/net/core/scm.c index 10f5c65f6a47..4681d8f9b45b 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -45,10 +45,10 @@ static __inline__ int scm_check_creds(struct ucred *creds) { if ((creds->pid == task_tgid_vnr(current) || capable(CAP_SYS_ADMIN)) && - ((creds->uid == current->uid || creds->uid == current->euid || - creds->uid == current->suid) || capable(CAP_SETUID)) && - ((creds->gid == current->gid || creds->gid == current->egid || - creds->gid == current->sgid) || capable(CAP_SETGID))) { + ((creds->uid == current_uid() || creds->uid == current_euid() || + creds->uid == current_suid()) || capable(CAP_SETUID)) && + ((creds->gid == current_gid() || creds->gid == current_egid() || + creds->gid == current_sgid()) || capable(CAP_SETGID))) { return 0; } return -EPERM; diff --git a/net/socket.c b/net/socket.c index 57550c3bcabe..62c7729527ff 100644 --- a/net/socket.c +++ b/net/socket.c @@ -491,8 +491,8 @@ static struct socket *sock_alloc(void) sock = SOCKET_I(inode); inode->i_mode = S_IFSOCK | S_IRWXUGO; - inode->i_uid = current->fsuid; - inode->i_gid = current->fsgid; + inode->i_uid = current_fsuid(); + inode->i_gid = current_fsgid(); get_cpu_var(sockets_in_use)++; put_cpu_var(sockets_in_use); -- cgit v1.2.3 From e9e349b051d98799b743ebf248cc2d986fedf090 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:13 +1100 Subject: KEYS: Disperse linux/key_ui.h Disperse the bits of linux/key_ui.h as the reason they were put here (keyfs) didn't get in. Signed-off-by: David Howells Reviewed-by: James Morris Signed-off-by: James Morris --- include/keys/keyring-type.h | 31 +++++++++++++++++++++ include/linux/key-ui.h | 66 --------------------------------------------- security/keys/internal.h | 31 ++++++++++++++++++++- security/keys/keyring.c | 1 + security/keys/request_key.c | 2 ++ 5 files changed, 64 insertions(+), 67 deletions(-) create mode 100644 include/keys/keyring-type.h delete mode 100644 include/linux/key-ui.h (limited to 'include') diff --git a/include/keys/keyring-type.h b/include/keys/keyring-type.h new file mode 100644 index 000000000000..843f872a4b63 --- /dev/null +++ b/include/keys/keyring-type.h @@ -0,0 +1,31 @@ +/* Keyring key type + * + * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _KEYS_KEYRING_TYPE_H +#define _KEYS_KEYRING_TYPE_H + +#include +#include + +/* + * the keyring payload contains a list of the keys to which the keyring is + * subscribed + */ +struct keyring_list { + struct rcu_head rcu; /* RCU deletion hook */ + unsigned short maxkeys; /* max keys this list can hold */ + unsigned short nkeys; /* number of keys currently held */ + unsigned short delkey; /* key to be unlinked by RCU */ + struct key *keys[0]; +}; + + +#endif /* _KEYS_KEYRING_TYPE_H */ diff --git a/include/linux/key-ui.h b/include/linux/key-ui.h deleted file mode 100644 index e8b8a7a5c496..000000000000 --- a/include/linux/key-ui.h +++ /dev/null @@ -1,66 +0,0 @@ -/* key-ui.h: key userspace interface stuff - * - * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ - -#ifndef _LINUX_KEY_UI_H -#define _LINUX_KEY_UI_H - -#include - -/* the key tree */ -extern struct rb_root key_serial_tree; -extern spinlock_t key_serial_lock; - -/* required permissions */ -#define KEY_VIEW 0x01 /* require permission to view attributes */ -#define KEY_READ 0x02 /* require permission to read content */ -#define KEY_WRITE 0x04 /* require permission to update / modify */ -#define KEY_SEARCH 0x08 /* require permission to search (keyring) or find (key) */ -#define KEY_LINK 0x10 /* require permission to link */ -#define KEY_SETATTR 0x20 /* require permission to change attributes */ -#define KEY_ALL 0x3f /* all the above permissions */ - -/* - * the keyring payload contains a list of the keys to which the keyring is - * subscribed - */ -struct keyring_list { - struct rcu_head rcu; /* RCU deletion hook */ - unsigned short maxkeys; /* max keys this list can hold */ - unsigned short nkeys; /* number of keys currently held */ - unsigned short delkey; /* key to be unlinked by RCU */ - struct key *keys[0]; -}; - -/* - * check to see whether permission is granted to use a key in the desired way - */ -extern int key_task_permission(const key_ref_t key_ref, - struct task_struct *context, - key_perm_t perm); - -static inline int key_permission(const key_ref_t key_ref, key_perm_t perm) -{ - return key_task_permission(key_ref, current, perm); -} - -extern key_ref_t lookup_user_key(struct task_struct *context, - key_serial_t id, int create, int partial, - key_perm_t perm); - -extern long join_session_keyring(const char *name); - -extern struct key_type *key_type_lookup(const char *type); -extern void key_type_put(struct key_type *ktype); - -#define key_negative_timeout 60 /* default timeout on a negative key's existence */ - - -#endif /* _LINUX_KEY_UI_H */ diff --git a/security/keys/internal.h b/security/keys/internal.h index b39f5c2e2c4b..a60c68138b4d 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -13,7 +13,6 @@ #define _INTERNAL_H #include -#include static inline __attribute__((format(printf, 1, 2))) void no_printk(const char *fmt, ...) @@ -82,6 +81,9 @@ extern struct mutex key_construction_mutex; extern wait_queue_head_t request_key_conswq; +extern struct key_type *key_type_lookup(const char *type); +extern void key_type_put(struct key_type *ktype); + extern int __key_link(struct key *keyring, struct key *key); extern key_ref_t __keyring_search_one(key_ref_t keyring_ref, @@ -118,6 +120,33 @@ extern struct key *request_key_and_link(struct key_type *type, struct key *dest_keyring, unsigned long flags); +extern key_ref_t lookup_user_key(struct task_struct *context, + key_serial_t id, int create, int partial, + key_perm_t perm); + +extern long join_session_keyring(const char *name); + +/* + * check to see whether permission is granted to use a key in the desired way + */ +extern int key_task_permission(const key_ref_t key_ref, + struct task_struct *context, + key_perm_t perm); + +static inline int key_permission(const key_ref_t key_ref, key_perm_t perm) +{ + return key_task_permission(key_ref, current, perm); +} + +/* required permissions */ +#define KEY_VIEW 0x01 /* require permission to view attributes */ +#define KEY_READ 0x02 /* require permission to read content */ +#define KEY_WRITE 0x04 /* require permission to update / modify */ +#define KEY_SEARCH 0x08 /* require permission to search (keyring) or find (key) */ +#define KEY_LINK 0x10 /* require permission to link */ +#define KEY_SETATTR 0x20 /* require permission to change attributes */ +#define KEY_ALL 0x3f /* all the above permissions */ + /* * request_key authorisation */ diff --git a/security/keys/keyring.c b/security/keys/keyring.c index a9ab8affc092..fdf75f901991 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include "internal.h" diff --git a/security/keys/request_key.c b/security/keys/request_key.c index a8ebc9520cac..91953c814497 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -19,6 +19,8 @@ #include #include "internal.h" +#define key_negative_timeout 60 /* default timeout on a negative key's existence */ + /* * wait_on_bit() sleep function for uninterruptible waiting */ -- cgit v1.2.3 From 8bbf4976b59fc9fc2861e79cab7beb3f6d647640 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:14 +1100 Subject: KEYS: Alter use of key instantiation link-to-keyring argument Alter the use of the key instantiation and negation functions' link-to-keyring arguments. Currently this specifies a keyring in the target process to link the key into, creating the keyring if it doesn't exist. This, however, can be a problem for copy-on-write credentials as it means that the instantiating process can alter the credentials of the requesting process. This patch alters the behaviour such that: (1) If keyctl_instantiate_key() or keyctl_negate_key() are given a specific keyring by ID (ringid >= 0), then that keyring will be used. (2) If keyctl_instantiate_key() or keyctl_negate_key() are given one of the special constants that refer to the requesting process's keyrings (KEY_SPEC_*_KEYRING, all <= 0), then: (a) If sys_request_key() was given a keyring to use (destringid) then the key will be attached to that keyring. (b) If sys_request_key() was given a NULL keyring, then the key being instantiated will be attached to the default keyring as set by keyctl_set_reqkey_keyring(). (3) No extra link will be made. Decision point (1) follows current behaviour, and allows those instantiators who've searched for a specifically named keyring in the requestor's keyring so as to partition the keys by type to still have their named keyrings. Decision point (2) allows the requestor to make sure that the key or keys that get produced by request_key() go where they want, whilst allowing the instantiator to request that the key is retained. This is mainly useful for situations where the instantiator makes a secondary request, the key for which should be retained by the initial requestor: +-----------+ +--------------+ +--------------+ | | | | | | | Requestor |------->| Instantiator |------->| Instantiator | | | | | | | +-----------+ +--------------+ +--------------+ request_key() request_key() This might be useful, for example, in Kerberos, where the requestor requests a ticket, and then the ticket instantiator requests the TGT, which someone else then has to go and fetch. The TGT, however, should be retained in the keyrings of the requestor, not the first instantiator. To make this explict an extra special keyring constant is also added. Signed-off-by: David Howells Reviewed-by: James Morris Signed-off-by: James Morris --- include/linux/key.h | 16 +++--- include/linux/keyctl.h | 4 +- kernel/kmod.c | 2 +- security/keys/internal.h | 12 ++-- security/keys/keyctl.c | 118 +++++++++++++++++++++++---------------- security/keys/process_keys.c | 88 ++++++++++++++++++----------- security/keys/request_key.c | 75 +++++++++++++++++-------- security/keys/request_key_auth.c | 5 +- 8 files changed, 199 insertions(+), 121 deletions(-) (limited to 'include') diff --git a/include/linux/key.h b/include/linux/key.h index 1b70e35a71e3..df709e1af3cd 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -287,11 +287,11 @@ extern void key_fsuid_changed(struct task_struct *tsk); extern void key_fsgid_changed(struct task_struct *tsk); extern void key_init(void); -#define __install_session_keyring(tsk, keyring) \ -({ \ - struct key *old_session = tsk->signal->session_keyring; \ - tsk->signal->session_keyring = keyring; \ - old_session; \ +#define __install_session_keyring(keyring) \ +({ \ + struct key *old_session = current->signal->session_keyring; \ + current->signal->session_keyring = keyring; \ + old_session; \ }) #else /* CONFIG_KEYS */ @@ -302,11 +302,11 @@ extern void key_init(void); #define key_revoke(k) do { } while(0) #define key_put(k) do { } while(0) #define key_ref_put(k) do { } while(0) -#define make_key_ref(k, p) ({ NULL; }) -#define key_ref_to_ptr(k) ({ NULL; }) +#define make_key_ref(k, p) NULL +#define key_ref_to_ptr(k) NULL #define is_key_possessed(k) 0 #define switch_uid_keyring(u) do { } while(0) -#define __install_session_keyring(t, k) ({ NULL; }) +#define __install_session_keyring(k) ({ NULL; }) #define copy_keys(f,t) 0 #define copy_thread_group_keys(t) 0 #define exit_keys(t) do { } while(0) diff --git a/include/linux/keyctl.h b/include/linux/keyctl.h index 656ee6b77a4a..c0688eb72093 100644 --- a/include/linux/keyctl.h +++ b/include/linux/keyctl.h @@ -1,6 +1,6 @@ /* keyctl.h: keyctl command IDs * - * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004, 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -20,6 +20,7 @@ #define KEY_SPEC_USER_SESSION_KEYRING -5 /* - key ID for UID-session keyring */ #define KEY_SPEC_GROUP_KEYRING -6 /* - key ID for GID-specific keyring */ #define KEY_SPEC_REQKEY_AUTH_KEY -7 /* - key ID for assumed request_key auth key */ +#define KEY_SPEC_REQUESTOR_KEYRING -8 /* - key ID for request_key() dest keyring */ /* request-key default keyrings */ #define KEY_REQKEY_DEFL_NO_CHANGE -1 @@ -30,6 +31,7 @@ #define KEY_REQKEY_DEFL_USER_KEYRING 4 #define KEY_REQKEY_DEFL_USER_SESSION_KEYRING 5 #define KEY_REQKEY_DEFL_GROUP_KEYRING 6 +#define KEY_REQKEY_DEFL_REQUESTOR_KEYRING 7 /* keyctl commands */ #define KEYCTL_GET_KEYRING_ID 0 /* ask for a keyring's ID */ diff --git a/kernel/kmod.c b/kernel/kmod.c index 3d3c3ea3a023..f044f8f57703 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -140,7 +140,7 @@ static int ____call_usermodehelper(void *data) /* Unblock all signals and set the session keyring. */ new_session = key_get(sub_info->ring); spin_lock_irq(¤t->sighand->siglock); - old_session = __install_session_keyring(current, new_session); + old_session = __install_session_keyring(new_session); flush_signal_handlers(current, 1); sigemptyset(¤t->blocked); recalc_sigpending(); diff --git a/security/keys/internal.h b/security/keys/internal.h index a60c68138b4d..d1586c629788 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -109,8 +109,9 @@ extern key_ref_t search_process_keyrings(struct key_type *type, extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check); -extern int install_thread_keyring(struct task_struct *tsk); -extern int install_process_keyring(struct task_struct *tsk); +extern int install_user_keyrings(void); +extern int install_thread_keyring(void); +extern int install_process_keyring(void); extern struct key *request_key_and_link(struct key_type *type, const char *description, @@ -120,8 +121,7 @@ extern struct key *request_key_and_link(struct key_type *type, struct key *dest_keyring, unsigned long flags); -extern key_ref_t lookup_user_key(struct task_struct *context, - key_serial_t id, int create, int partial, +extern key_ref_t lookup_user_key(key_serial_t id, int create, int partial, key_perm_t perm); extern long join_session_keyring(const char *name); @@ -152,6 +152,7 @@ static inline int key_permission(const key_ref_t key_ref, key_perm_t perm) */ struct request_key_auth { struct key *target_key; + struct key *dest_keyring; struct task_struct *context; void *callout_info; size_t callout_len; @@ -161,7 +162,8 @@ struct request_key_auth { extern struct key_type key_type_request_key_auth; extern struct key *request_key_auth_new(struct key *target, const void *callout_info, - size_t callout_len); + size_t callout_len, + struct key *dest_keyring); extern struct key *key_get_instantiation_authkey(key_serial_t target_id); diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 3f09e5b2a784..fcce331eca72 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -103,7 +103,7 @@ asmlinkage long sys_add_key(const char __user *_type, } /* find the target keyring (which must be writable) */ - keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error3; @@ -185,7 +185,7 @@ asmlinkage long sys_request_key(const char __user *_type, /* get the destination keyring if specified */ dest_ref = NULL; if (destringid) { - dest_ref = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); + dest_ref = lookup_user_key(destringid, 1, 0, KEY_WRITE); if (IS_ERR(dest_ref)) { ret = PTR_ERR(dest_ref); goto error3; @@ -235,7 +235,7 @@ long keyctl_get_keyring_ID(key_serial_t id, int create) key_ref_t key_ref; long ret; - key_ref = lookup_user_key(NULL, id, create, 0, KEY_SEARCH); + key_ref = lookup_user_key(id, create, 0, KEY_SEARCH); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -308,7 +308,7 @@ long keyctl_update_key(key_serial_t id, } /* find the target key (which must be writable) */ - key_ref = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); + key_ref = lookup_user_key(id, 0, 0, KEY_WRITE); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error2; @@ -336,7 +336,7 @@ long keyctl_revoke_key(key_serial_t id) key_ref_t key_ref; long ret; - key_ref = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); + key_ref = lookup_user_key(id, 0, 0, KEY_WRITE); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -362,7 +362,7 @@ long keyctl_keyring_clear(key_serial_t ringid) key_ref_t keyring_ref; long ret; - keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error; @@ -388,13 +388,13 @@ long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) key_ref_t keyring_ref, key_ref; long ret; - keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error; } - key_ref = lookup_user_key(NULL, id, 1, 0, KEY_LINK); + key_ref = lookup_user_key(id, 1, 0, KEY_LINK); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error2; @@ -422,13 +422,13 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) key_ref_t keyring_ref, key_ref; long ret; - keyring_ref = lookup_user_key(NULL, ringid, 0, 0, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, 0, 0, KEY_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error; } - key_ref = lookup_user_key(NULL, id, 0, 0, 0); + key_ref = lookup_user_key(id, 0, 0, 0); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error2; @@ -464,7 +464,7 @@ long keyctl_describe_key(key_serial_t keyid, char *tmpbuf; long ret; - key_ref = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW); + key_ref = lookup_user_key(keyid, 0, 1, KEY_VIEW); if (IS_ERR(key_ref)) { /* viewing a key under construction is permitted if we have the * authorisation token handy */ @@ -472,7 +472,7 @@ long keyctl_describe_key(key_serial_t keyid, instkey = key_get_instantiation_authkey(keyid); if (!IS_ERR(instkey)) { key_put(instkey); - key_ref = lookup_user_key(NULL, keyid, + key_ref = lookup_user_key(keyid, 0, 1, 0); if (!IS_ERR(key_ref)) goto okay; @@ -557,7 +557,7 @@ long keyctl_keyring_search(key_serial_t ringid, } /* get the keyring at which to begin the search */ - keyring_ref = lookup_user_key(NULL, ringid, 0, 0, KEY_SEARCH); + keyring_ref = lookup_user_key(ringid, 0, 0, KEY_SEARCH); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error2; @@ -566,7 +566,7 @@ long keyctl_keyring_search(key_serial_t ringid, /* get the destination keyring if specified */ dest_ref = NULL; if (destringid) { - dest_ref = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); + dest_ref = lookup_user_key(destringid, 1, 0, KEY_WRITE); if (IS_ERR(dest_ref)) { ret = PTR_ERR(dest_ref); goto error3; @@ -636,7 +636,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) long ret; /* find the key first */ - key_ref = lookup_user_key(NULL, keyid, 0, 0, 0); + key_ref = lookup_user_key(keyid, 0, 0, 0); if (IS_ERR(key_ref)) { ret = -ENOKEY; goto error; @@ -699,7 +699,7 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) if (uid == (uid_t) -1 && gid == (gid_t) -1) goto error; - key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); + key_ref = lookup_user_key(id, 1, 1, KEY_SETATTR); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -804,7 +804,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) goto error; - key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); + key_ref = lookup_user_key(id, 1, 1, KEY_SETATTR); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -829,6 +829,43 @@ error: } /* end keyctl_setperm_key() */ +/* + * get the destination keyring for instantiation + */ +static long get_instantiation_keyring(key_serial_t ringid, + struct request_key_auth *rka, + struct key **_dest_keyring) +{ + key_ref_t dkref; + + /* just return a NULL pointer if we weren't asked to make a link */ + if (ringid == 0) { + *_dest_keyring = NULL; + return 0; + } + + /* if a specific keyring is nominated by ID, then use that */ + if (ringid > 0) { + dkref = lookup_user_key(ringid, 1, 0, KEY_WRITE); + if (IS_ERR(dkref)) + return PTR_ERR(dkref); + *_dest_keyring = key_ref_to_ptr(dkref); + return 0; + } + + if (ringid == KEY_SPEC_REQKEY_AUTH_KEY) + return -EINVAL; + + /* otherwise specify the destination keyring recorded in the + * authorisation key (any KEY_SPEC_*_KEYRING) */ + if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) { + *_dest_keyring = rka->dest_keyring; + return 0; + } + + return -ENOKEY; +} + /*****************************************************************************/ /* * instantiate the key with the specified payload, and, if one is given, link @@ -840,8 +877,7 @@ long keyctl_instantiate_key(key_serial_t id, key_serial_t ringid) { struct request_key_auth *rka; - struct key *instkey; - key_ref_t keyring_ref; + struct key *instkey, *dest_keyring; void *payload; long ret; bool vm = false; @@ -883,21 +919,15 @@ long keyctl_instantiate_key(key_serial_t id, /* find the destination keyring amongst those belonging to the * requesting task */ - keyring_ref = NULL; - if (ringid) { - keyring_ref = lookup_user_key(rka->context, ringid, 1, 0, - KEY_WRITE); - if (IS_ERR(keyring_ref)) { - ret = PTR_ERR(keyring_ref); - goto error2; - } - } + ret = get_instantiation_keyring(ringid, rka, &dest_keyring); + if (ret < 0) + goto error2; /* instantiate the key and link it into a keyring */ ret = key_instantiate_and_link(rka->target_key, payload, plen, - key_ref_to_ptr(keyring_ref), instkey); + dest_keyring, instkey); - key_ref_put(keyring_ref); + key_put(dest_keyring); /* discard the assumed authority if it's just been disabled by * instantiation of the key */ @@ -924,8 +954,7 @@ error: long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) { struct request_key_auth *rka; - struct key *instkey; - key_ref_t keyring_ref; + struct key *instkey, *dest_keyring; long ret; /* the appropriate instantiation authorisation key must have been @@ -941,20 +970,15 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) /* find the destination keyring if present (which must also be * writable) */ - keyring_ref = NULL; - if (ringid) { - keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); - if (IS_ERR(keyring_ref)) { - ret = PTR_ERR(keyring_ref); - goto error; - } - } + ret = get_instantiation_keyring(ringid, rka, &dest_keyring); + if (ret < 0) + goto error; /* instantiate the key and link it into a keyring */ ret = key_negate_and_link(rka->target_key, timeout, - key_ref_to_ptr(keyring_ref), instkey); + dest_keyring, instkey); - key_ref_put(keyring_ref); + key_put(dest_keyring); /* discard the assumed authority if it's just been disabled by * instantiation of the key */ @@ -979,13 +1003,13 @@ long keyctl_set_reqkey_keyring(int reqkey_defl) switch (reqkey_defl) { case KEY_REQKEY_DEFL_THREAD_KEYRING: - ret = install_thread_keyring(current); + ret = install_thread_keyring(); if (ret < 0) return ret; goto set; case KEY_REQKEY_DEFL_PROCESS_KEYRING: - ret = install_process_keyring(current); + ret = install_process_keyring(); if (ret < 0) return ret; @@ -1018,7 +1042,7 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout) time_t expiry; long ret; - key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); + key_ref = lookup_user_key(id, 1, 1, KEY_SETATTR); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -1105,7 +1129,7 @@ long keyctl_get_security(key_serial_t keyid, char *context; long ret; - key_ref = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW); + key_ref = lookup_user_key(keyid, 0, 1, KEY_VIEW); if (IS_ERR(key_ref)) { if (PTR_ERR(key_ref) != -EACCES) return PTR_ERR(key_ref); @@ -1117,7 +1141,7 @@ long keyctl_get_security(key_serial_t keyid, return PTR_ERR(key_ref); key_put(instkey); - key_ref = lookup_user_key(NULL, keyid, 0, 1, 0); + key_ref = lookup_user_key(keyid, 0, 1, 0); if (IS_ERR(key_ref)) return PTR_ERR(key_ref); } diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 5be6d018759a..1c793b7090a7 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -40,9 +40,9 @@ struct key_user root_key_user = { /* * install user and user session keyrings for a particular UID */ -static int install_user_keyrings(struct task_struct *tsk) +int install_user_keyrings(void) { - struct user_struct *user = tsk->user; + struct user_struct *user = current->user; struct key *uid_keyring, *session_keyring; char buf[20]; int ret; @@ -67,7 +67,7 @@ static int install_user_keyrings(struct task_struct *tsk) uid_keyring = find_keyring_by_name(buf, true); if (IS_ERR(uid_keyring)) { uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, - tsk, KEY_ALLOC_IN_QUOTA, + current, KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(uid_keyring)) { ret = PTR_ERR(uid_keyring); @@ -83,7 +83,8 @@ static int install_user_keyrings(struct task_struct *tsk) if (IS_ERR(session_keyring)) { session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, - tsk, KEY_ALLOC_IN_QUOTA, NULL); + current, KEY_ALLOC_IN_QUOTA, + NULL); if (IS_ERR(session_keyring)) { ret = PTR_ERR(session_keyring); goto error_release; @@ -146,8 +147,9 @@ void switch_uid_keyring(struct user_struct *new_user) /* * install a fresh thread keyring, discarding the old one */ -int install_thread_keyring(struct task_struct *tsk) +int install_thread_keyring(void) { + struct task_struct *tsk = current; struct key *keyring, *old; char buf[20]; int ret; @@ -178,8 +180,9 @@ error: /* * make sure a process keyring is installed */ -int install_process_keyring(struct task_struct *tsk) +int install_process_keyring(void) { + struct task_struct *tsk = current; struct key *keyring; char buf[20]; int ret; @@ -218,9 +221,9 @@ error: * install a session keyring, discarding the old one * - if a keyring is not supplied, an empty one is invented */ -static int install_session_keyring(struct task_struct *tsk, - struct key *keyring) +static int install_session_keyring(struct key *keyring) { + struct task_struct *tsk = current; unsigned long flags; struct key *old; char buf[20]; @@ -572,93 +575,91 @@ static int lookup_user_key_possessed(const struct key *key, const void *target) * - don't create special keyrings unless so requested * - partially constructed keys aren't found unless requested */ -key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, - int create, int partial, key_perm_t perm) +key_ref_t lookup_user_key(key_serial_t id, int create, int partial, + key_perm_t perm) { + struct request_key_auth *rka; + struct task_struct *t = current; key_ref_t key_ref, skey_ref; struct key *key; int ret; - if (!context) - context = current; - key_ref = ERR_PTR(-ENOKEY); switch (id) { case KEY_SPEC_THREAD_KEYRING: - if (!context->thread_keyring) { + if (!t->thread_keyring) { if (!create) goto error; - ret = install_thread_keyring(context); + ret = install_thread_keyring(); if (ret < 0) { key = ERR_PTR(ret); goto error; } } - key = context->thread_keyring; + key = t->thread_keyring; atomic_inc(&key->usage); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_PROCESS_KEYRING: - if (!context->signal->process_keyring) { + if (!t->signal->process_keyring) { if (!create) goto error; - ret = install_process_keyring(context); + ret = install_process_keyring(); if (ret < 0) { key = ERR_PTR(ret); goto error; } } - key = context->signal->process_keyring; + key = t->signal->process_keyring; atomic_inc(&key->usage); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_SESSION_KEYRING: - if (!context->signal->session_keyring) { + if (!t->signal->session_keyring) { /* always install a session keyring upon access if one * doesn't exist yet */ - ret = install_user_keyrings(context); + ret = install_user_keyrings(); if (ret < 0) goto error; - ret = install_session_keyring( - context, context->user->session_keyring); + ret = install_session_keyring(t->user->session_keyring); if (ret < 0) goto error; } rcu_read_lock(); - key = rcu_dereference(context->signal->session_keyring); + key = rcu_dereference(t->signal->session_keyring); atomic_inc(&key->usage); rcu_read_unlock(); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_USER_KEYRING: - if (!context->user->uid_keyring) { - ret = install_user_keyrings(context); + if (!t->user->uid_keyring) { + ret = install_user_keyrings(); if (ret < 0) goto error; } - key = context->user->uid_keyring; + key = t->user->uid_keyring; atomic_inc(&key->usage); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_USER_SESSION_KEYRING: - if (!context->user->session_keyring) { - ret = install_user_keyrings(context); + if (!t->user->session_keyring) { + ret = install_user_keyrings(); if (ret < 0) goto error; } - key = context->user->session_keyring; + key = t->user->session_keyring; atomic_inc(&key->usage); key_ref = make_key_ref(key, 1); break; @@ -669,7 +670,7 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, goto error; case KEY_SPEC_REQKEY_AUTH_KEY: - key = context->request_key_auth; + key = t->request_key_auth; if (!key) goto error; @@ -677,6 +678,25 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, key_ref = make_key_ref(key, 1); break; + case KEY_SPEC_REQUESTOR_KEYRING: + if (!t->request_key_auth) + goto error; + + down_read(&t->request_key_auth->sem); + if (t->request_key_auth->flags & KEY_FLAG_REVOKED) { + key_ref = ERR_PTR(-EKEYREVOKED); + key = NULL; + } else { + rka = t->request_key_auth->payload.data; + key = rka->dest_keyring; + atomic_inc(&key->usage); + } + up_read(&t->request_key_auth->sem); + if (!key) + goto error; + key_ref = make_key_ref(key, 1); + break; + default: key_ref = ERR_PTR(-EINVAL); if (id < 1) @@ -725,7 +745,7 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, goto invalid_key; /* check the permissions */ - ret = key_task_permission(key_ref, context, perm); + ret = key_task_permission(key_ref, t, perm); if (ret < 0) goto invalid_key; @@ -754,7 +774,7 @@ long join_session_keyring(const char *name) /* if no name is provided, install an anonymous keyring */ if (!name) { - ret = install_session_keyring(tsk, NULL); + ret = install_session_keyring(NULL); if (ret < 0) goto error; @@ -784,7 +804,7 @@ long join_session_keyring(const char *name) } /* we've got a keyring - now to install it */ - ret = install_session_keyring(tsk, keyring); + ret = install_session_keyring(keyring); if (ret < 0) goto error2; diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 91953c814497..8e9d93b4a402 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -76,6 +76,10 @@ static int call_sbin_request_key(struct key_construction *cons, kenter("{%d},{%d},%s", key->serial, authkey->serial, op); + ret = install_user_keyrings(); + if (ret < 0) + goto error_alloc; + /* allocate a new session keyring */ sprintf(desc, "_req.%u", key->serial); @@ -165,7 +169,8 @@ error_alloc: * - we ignore program failure and go on key status instead */ static int construct_key(struct key *key, const void *callout_info, - size_t callout_len, void *aux) + size_t callout_len, void *aux, + struct key *dest_keyring) { struct key_construction *cons; request_key_actor_t actor; @@ -179,7 +184,8 @@ static int construct_key(struct key *key, const void *callout_info, return -ENOMEM; /* allocate an authorisation key */ - authkey = request_key_auth_new(key, callout_info, callout_len); + authkey = request_key_auth_new(key, callout_info, callout_len, + dest_keyring); if (IS_ERR(authkey)) { kfree(cons); ret = PTR_ERR(authkey); @@ -207,27 +213,48 @@ static int construct_key(struct key *key, const void *callout_info, } /* - * link a key to the appropriate destination keyring - * - the caller must hold a write lock on the destination keyring + * get the appropriate destination keyring for the request + * - we return whatever keyring we select with an extra reference upon it which + * the caller must release */ -static void construct_key_make_link(struct key *key, struct key *dest_keyring) +static void construct_get_dest_keyring(struct key **_dest_keyring) { + struct request_key_auth *rka; struct task_struct *tsk = current; - struct key *drop = NULL; + struct key *dest_keyring = *_dest_keyring, *authkey; - kenter("{%d},%p", key->serial, dest_keyring); + kenter("%p", dest_keyring); /* find the appropriate keyring */ - if (!dest_keyring) { + if (dest_keyring) { + /* the caller supplied one */ + key_get(dest_keyring); + } else { + /* use a default keyring; falling through the cases until we + * find one that we actually have */ switch (tsk->jit_keyring) { case KEY_REQKEY_DEFL_DEFAULT: + case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: + if (tsk->request_key_auth) { + authkey = tsk->request_key_auth; + down_read(&authkey->sem); + rka = authkey->payload.data; + if (!test_bit(KEY_FLAG_REVOKED, + &authkey->flags)) + dest_keyring = + key_get(rka->dest_keyring); + up_read(&authkey->sem); + if (dest_keyring) + break; + } + case KEY_REQKEY_DEFL_THREAD_KEYRING: - dest_keyring = tsk->thread_keyring; + dest_keyring = key_get(tsk->thread_keyring); if (dest_keyring) break; case KEY_REQKEY_DEFL_PROCESS_KEYRING: - dest_keyring = tsk->signal->process_keyring; + dest_keyring = key_get(tsk->signal->process_keyring); if (dest_keyring) break; @@ -236,17 +263,16 @@ static void construct_key_make_link(struct key *key, struct key *dest_keyring) dest_keyring = key_get( rcu_dereference(tsk->signal->session_keyring)); rcu_read_unlock(); - drop = dest_keyring; if (dest_keyring) break; case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: - dest_keyring = tsk->user->session_keyring; + dest_keyring = key_get(tsk->user->session_keyring); break; case KEY_REQKEY_DEFL_USER_KEYRING: - dest_keyring = tsk->user->uid_keyring; + dest_keyring = key_get(tsk->user->uid_keyring); break; case KEY_REQKEY_DEFL_GROUP_KEYRING: @@ -255,10 +281,9 @@ static void construct_key_make_link(struct key *key, struct key *dest_keyring) } } - /* and attach the key to it */ - __key_link(dest_keyring, key); - key_put(drop); - kleave(""); + *_dest_keyring = dest_keyring; + kleave(" [dk %d]", key_serial(dest_keyring)); + return; } /* @@ -288,8 +313,7 @@ static int construct_alloc_key(struct key_type *type, set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); - if (dest_keyring) - down_write(&dest_keyring->sem); + down_write(&dest_keyring->sem); /* attach the key to the destination keyring under lock, but we do need * to do another check just in case someone beat us to it whilst we @@ -301,12 +325,10 @@ static int construct_alloc_key(struct key_type *type, if (!IS_ERR(key_ref)) goto key_already_present; - if (dest_keyring) - construct_key_make_link(key, dest_keyring); + __key_link(dest_keyring, key); mutex_unlock(&key_construction_mutex); - if (dest_keyring) - up_write(&dest_keyring->sem); + up_write(&dest_keyring->sem); mutex_unlock(&user->cons_lock); *_key = key; kleave(" = 0 [%d]", key_serial(key)); @@ -348,21 +370,26 @@ static struct key *construct_key_and_link(struct key_type *type, if (!user) return ERR_PTR(-ENOMEM); + construct_get_dest_keyring(&dest_keyring); + ret = construct_alloc_key(type, description, dest_keyring, flags, user, &key); key_user_put(user); if (ret == 0) { - ret = construct_key(key, callout_info, callout_len, aux); + ret = construct_key(key, callout_info, callout_len, aux, + dest_keyring); if (ret < 0) goto construction_failed; } + key_put(dest_keyring); return key; construction_failed: key_negate_and_link(key, key_negative_timeout, NULL, NULL); key_put(key); + key_put(dest_keyring); return ERR_PTR(ret); } diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c index 729156b3485e..1762d44711d5 100644 --- a/security/keys/request_key_auth.c +++ b/security/keys/request_key_auth.c @@ -128,6 +128,7 @@ static void request_key_auth_destroy(struct key *key) } key_put(rka->target_key); + key_put(rka->dest_keyring); kfree(rka->callout_info); kfree(rka); @@ -139,7 +140,7 @@ static void request_key_auth_destroy(struct key *key) * access to the caller's security data */ struct key *request_key_auth_new(struct key *target, const void *callout_info, - size_t callout_len) + size_t callout_len, struct key *dest_keyring) { struct request_key_auth *rka, *irka; struct key *authkey = NULL; @@ -188,6 +189,7 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, } rka->target_key = key_get(target); + rka->dest_keyring = key_get(dest_keyring); memcpy(rka->callout_info, callout_info, callout_len); rka->callout_len = callout_len; @@ -223,6 +225,7 @@ error_inst: key_put(authkey); error_alloc: key_put(rka->target_key); + key_put(rka->dest_keyring); kfree(rka->callout_info); kfree(rka); kleave("= %d", ret); -- cgit v1.2.3 From 1cdcbec1a3372c0c49c59d292e708fd07b509f18 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:14 +1100 Subject: CRED: Neuter sys_capset() Take away the ability for sys_capset() to affect processes other than current. This means that current will not need to lock its own credentials when reading them against interference by other processes. This has effectively been the case for a while anyway, since: (1) Without LSM enabled, sys_capset() is disallowed. (2) With file-based capabilities, sys_capset() is neutered. Signed-off-by: David Howells Acked-by: Serge Hallyn Acked-by: Andrew G. Morgan Acked-by: James Morris Signed-off-by: James Morris --- fs/open.c | 12 +-- include/linux/security.h | 48 ++++------ kernel/capability.c | 227 +++++------------------------------------------ security/commoncap.c | 29 ++---- security/security.c | 18 ++-- security/selinux/hooks.c | 10 +-- 6 files changed, 61 insertions(+), 283 deletions(-) (limited to 'include') diff --git a/fs/open.c b/fs/open.c index 83cdb9dee0c1..500cc0c54762 100644 --- a/fs/open.c +++ b/fs/open.c @@ -441,17 +441,7 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) current->fsgid = current->gid; if (!issecure(SECURE_NO_SETUID_FIXUP)) { - /* - * Clear the capabilities if we switch to a non-root user - */ -#ifndef CONFIG_SECURITY_FILE_CAPABILITIES - /* - * FIXME: There is a race here against sys_capset. The - * capabilities can change yet we will restore the old - * value below. We should hold task_capabilities_lock, - * but we cannot because user_path_at can sleep. - */ -#endif /* ndef CONFIG_SECURITY_FILE_CAPABILITIES */ + /* Clear the capabilities if we switch to a non-root user */ if (current->uid) old_cap = cap_set_effective(__cap_empty_set); else diff --git a/include/linux/security.h b/include/linux/security.h index 5fe28a671cd3..d1ce8beddbd7 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -53,8 +53,8 @@ extern int cap_settime(struct timespec *ts, struct timezone *tz); extern int cap_ptrace_may_access(struct task_struct *child, unsigned int mode); extern int cap_ptrace_traceme(struct task_struct *parent); extern int cap_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); -extern int cap_capset_check(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); -extern void cap_capset_set(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); +extern int cap_capset_check(kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); +extern void cap_capset_set(kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); extern int cap_bprm_set_security(struct linux_binprm *bprm); extern void cap_bprm_apply_creds(struct linux_binprm *bprm, int unsafe); extern int cap_bprm_secureexec(struct linux_binprm *bprm); @@ -1191,24 +1191,14 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * Return 0 if the capability sets were successfully obtained. * @capset_check: * Check permission before setting the @effective, @inheritable, and - * @permitted capability sets for the @target process. - * Caveat: @target is also set to current if a set of processes is - * specified (i.e. all processes other than current and init or a - * particular process group). Hence, the capset_set hook may need to - * revalidate permission to the actual target process. - * @target contains the task_struct structure for target process. + * @permitted capability sets for the current process. * @effective contains the effective capability set. * @inheritable contains the inheritable capability set. * @permitted contains the permitted capability set. * Return 0 if permission is granted. * @capset_set: * Set the @effective, @inheritable, and @permitted capability sets for - * the @target process. Since capset_check cannot always check permission - * to the real @target process, this hook may also perform permission - * checking to determine if the current process is allowed to set the - * capability sets of the @target process. However, this hook has no way - * of returning an error due to the structure of the sys_capset code. - * @target contains the task_struct structure for target process. + * the current process. * @effective contains the effective capability set. * @inheritable contains the inheritable capability set. * @permitted contains the permitted capability set. @@ -1303,12 +1293,10 @@ struct security_operations { int (*capget) (struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); - int (*capset_check) (struct task_struct *target, - kernel_cap_t *effective, + int (*capset_check) (kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); - void (*capset_set) (struct task_struct *target, - kernel_cap_t *effective, + void (*capset_set) (kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); int (*capable) (struct task_struct *tsk, int cap, int audit); @@ -1572,12 +1560,10 @@ int security_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); -int security_capset_check(struct task_struct *target, - kernel_cap_t *effective, +int security_capset_check(kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); -void security_capset_set(struct task_struct *target, - kernel_cap_t *effective, +void security_capset_set(kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); int security_capable(struct task_struct *tsk, int cap); @@ -1769,20 +1755,18 @@ static inline int security_capget(struct task_struct *target, return cap_capget(target, effective, inheritable, permitted); } -static inline int security_capset_check(struct task_struct *target, - kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) +static inline int security_capset_check(kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) { - return cap_capset_check(target, effective, inheritable, permitted); + return cap_capset_check(effective, inheritable, permitted); } -static inline void security_capset_set(struct task_struct *target, - kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) +static inline void security_capset_set(kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) { - cap_capset_set(target, effective, inheritable, permitted); + cap_capset_set(effective, inheritable, permitted); } static inline int security_capable(struct task_struct *tsk, int cap) diff --git a/kernel/capability.c b/kernel/capability.c index adb262f83de1..58b00519624a 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -127,160 +127,6 @@ static int cap_validate_magic(cap_user_header_t header, unsigned *tocopy) return 0; } -#ifndef CONFIG_SECURITY_FILE_CAPABILITIES - -/* - * Without filesystem capability support, we nominally support one process - * setting the capabilities of another - */ -static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp, - kernel_cap_t *pIp, kernel_cap_t *pPp) -{ - struct task_struct *target; - int ret; - - spin_lock(&task_capability_lock); - read_lock(&tasklist_lock); - - if (pid && pid != task_pid_vnr(current)) { - target = find_task_by_vpid(pid); - if (!target) { - ret = -ESRCH; - goto out; - } - } else - target = current; - - ret = security_capget(target, pEp, pIp, pPp); - -out: - read_unlock(&tasklist_lock); - spin_unlock(&task_capability_lock); - - return ret; -} - -/* - * cap_set_pg - set capabilities for all processes in a given process - * group. We call this holding task_capability_lock and tasklist_lock. - */ -static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) -{ - struct task_struct *g, *target; - int ret = -EPERM; - int found = 0; - struct pid *pgrp; - - spin_lock(&task_capability_lock); - read_lock(&tasklist_lock); - - pgrp = find_vpid(pgrp_nr); - do_each_pid_task(pgrp, PIDTYPE_PGID, g) { - target = g; - while_each_thread(g, target) { - if (!security_capset_check(target, effective, - inheritable, permitted)) { - security_capset_set(target, effective, - inheritable, permitted); - ret = 0; - } - found = 1; - } - } while_each_pid_task(pgrp, PIDTYPE_PGID, g); - - read_unlock(&tasklist_lock); - spin_unlock(&task_capability_lock); - - if (!found) - ret = 0; - return ret; -} - -/* - * cap_set_all - set capabilities for all processes other than init - * and self. We call this holding task_capability_lock and tasklist_lock. - */ -static inline int cap_set_all(kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) -{ - struct task_struct *g, *target; - int ret = -EPERM; - int found = 0; - - spin_lock(&task_capability_lock); - read_lock(&tasklist_lock); - - do_each_thread(g, target) { - if (target == current - || is_container_init(target->group_leader)) - continue; - found = 1; - if (security_capset_check(target, effective, inheritable, - permitted)) - continue; - ret = 0; - security_capset_set(target, effective, inheritable, permitted); - } while_each_thread(g, target); - - read_unlock(&tasklist_lock); - spin_unlock(&task_capability_lock); - - if (!found) - ret = 0; - - return ret; -} - -/* - * Given the target pid does not refer to the current process we - * need more elaborate support... (This support is not present when - * filesystem capabilities are configured.) - */ -static inline int do_sys_capset_other_tasks(pid_t pid, kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) -{ - struct task_struct *target; - int ret; - - if (!capable(CAP_SETPCAP)) - return -EPERM; - - if (pid == -1) /* all procs other than current and init */ - return cap_set_all(effective, inheritable, permitted); - - else if (pid < 0) /* all procs in process group */ - return cap_set_pg(-pid, effective, inheritable, permitted); - - /* target != current */ - spin_lock(&task_capability_lock); - read_lock(&tasklist_lock); - - target = find_task_by_vpid(pid); - if (!target) - ret = -ESRCH; - else { - ret = security_capset_check(target, effective, inheritable, - permitted); - - /* having verified that the proposed changes are legal, - we now put them into effect. */ - if (!ret) - security_capset_set(target, effective, inheritable, - permitted); - } - - read_unlock(&tasklist_lock); - spin_unlock(&task_capability_lock); - - return ret; -} - -#else /* ie., def CONFIG_SECURITY_FILE_CAPABILITIES */ - /* * If we have configured with filesystem capability support, then the * only thing that can change the capabilities of the current process @@ -314,22 +160,6 @@ static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp, return ret; } -/* - * With filesystem capability support configured, the kernel does not - * permit the changing of capabilities in one process by another - * process. (CAP_SETPCAP has much less broad semantics when configured - * this way.) - */ -static inline int do_sys_capset_other_tasks(pid_t pid, - kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) -{ - return -EPERM; -} - -#endif /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ - /* * Atomically modify the effective capabilities returning the original * value. No permission check is performed here - it is assumed that the @@ -424,16 +254,14 @@ asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr) * @data: pointer to struct that contains the effective, permitted, * and inheritable capabilities * - * Set capabilities for a given process, all processes, or all - * processes in a given process group. + * Set capabilities for the current process only. The ability to any other + * process(es) has been deprecated and removed. * * The restrictions on setting capabilities are specified as: * - * [pid is for the 'target' task. 'current' is the calling task.] - * - * I: any raised capabilities must be a subset of the (old current) permitted - * P: any raised capabilities must be a subset of the (old current) permitted - * E: must be set to a subset of (new target) permitted + * I: any raised capabilities must be a subset of the old permitted + * P: any raised capabilities must be a subset of the old permitted + * E: must be set to a subset of new permitted * * Returns 0 on success and < 0 on error. */ @@ -452,10 +280,13 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) if (get_user(pid, &header->pid)) return -EFAULT; + /* may only affect current now */ + if (pid != 0 && pid != task_pid_vnr(current)) + return -EPERM; + if (copy_from_user(&kdata, data, tocopy - * sizeof(struct __user_cap_data_struct))) { + * sizeof(struct __user_cap_data_struct))) return -EFAULT; - } for (i = 0; i < tocopy; i++) { effective.cap[i] = kdata[i].effective; @@ -473,32 +304,20 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) if (ret) return ret; - if (pid && (pid != task_pid_vnr(current))) - ret = do_sys_capset_other_tasks(pid, &effective, &inheritable, - &permitted); - else { - /* - * This lock is required even when filesystem - * capability support is configured - it protects the - * sys_capget() call from returning incorrect data in - * the case that the targeted process is not the - * current one. - */ - spin_lock(&task_capability_lock); - - ret = security_capset_check(current, &effective, &inheritable, - &permitted); - /* - * Having verified that the proposed changes are - * legal, we now put them into effect. - */ - if (!ret) - security_capset_set(current, &effective, &inheritable, - &permitted); - spin_unlock(&task_capability_lock); - } - + /* This lock is required even when filesystem capability support is + * configured - it protects the sys_capget() call from returning + * incorrect data in the case that the targeted process is not the + * current one. + */ + spin_lock(&task_capability_lock); + ret = security_capset_check(&effective, &inheritable, &permitted); + /* Having verified that the proposed changes are legal, we now put them + * into effect. + */ + if (!ret) + security_capset_set(&effective, &inheritable, &permitted); + spin_unlock(&task_capability_lock); return ret; } diff --git a/security/commoncap.c b/security/commoncap.c index 8283271f0768..e3f36ef629fa 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -96,15 +96,6 @@ int cap_capget (struct task_struct *target, kernel_cap_t *effective, #ifdef CONFIG_SECURITY_FILE_CAPABILITIES -static inline int cap_block_setpcap(struct task_struct *target) -{ - /* - * No support for remote process capability manipulation with - * filesystem capability support. - */ - return (target != current); -} - static inline int cap_inh_is_capped(void) { /* @@ -119,7 +110,6 @@ static inline int cap_limit_ptraced_target(void) { return 1; } #else /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ -static inline int cap_block_setpcap(struct task_struct *t) { return 0; } static inline int cap_inh_is_capped(void) { return 1; } static inline int cap_limit_ptraced_target(void) { @@ -128,21 +118,18 @@ static inline int cap_limit_ptraced_target(void) #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ -int cap_capset_check (struct task_struct *target, kernel_cap_t *effective, +int cap_capset_check (kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted) { - if (cap_block_setpcap(target)) { - return -EPERM; - } if (cap_inh_is_capped() && !cap_issubset(*inheritable, - cap_combine(target->cap_inheritable, + cap_combine(current->cap_inheritable, current->cap_permitted))) { /* incapable of using this inheritable set */ return -EPERM; } if (!cap_issubset(*inheritable, - cap_combine(target->cap_inheritable, + cap_combine(current->cap_inheritable, current->cap_bset))) { /* no new pI capabilities outside bounding set */ return -EPERM; @@ -150,7 +137,7 @@ int cap_capset_check (struct task_struct *target, kernel_cap_t *effective, /* verify restrictions on target's new Permitted set */ if (!cap_issubset (*permitted, - cap_combine (target->cap_permitted, + cap_combine (current->cap_permitted, current->cap_permitted))) { return -EPERM; } @@ -163,12 +150,12 @@ int cap_capset_check (struct task_struct *target, kernel_cap_t *effective, return 0; } -void cap_capset_set (struct task_struct *target, kernel_cap_t *effective, +void cap_capset_set (kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted) { - target->cap_effective = *effective; - target->cap_inheritable = *inheritable; - target->cap_permitted = *permitted; + current->cap_effective = *effective; + current->cap_inheritable = *inheritable; + current->cap_permitted = *permitted; } static inline void bprm_clear_caps(struct linux_binprm *bprm) diff --git a/security/security.c b/security/security.c index 346f21e0ec2c..dca37381e2a7 100644 --- a/security/security.c +++ b/security/security.c @@ -145,20 +145,18 @@ int security_capget(struct task_struct *target, return security_ops->capget(target, effective, inheritable, permitted); } -int security_capset_check(struct task_struct *target, - kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) +int security_capset_check(kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) { - return security_ops->capset_check(target, effective, inheritable, permitted); + return security_ops->capset_check(effective, inheritable, permitted); } -void security_capset_set(struct task_struct *target, - kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) +void security_capset_set(kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) { - security_ops->capset_set(target, effective, inheritable, permitted); + security_ops->capset_set(effective, inheritable, permitted); } int security_capable(struct task_struct *tsk, int cap) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 378dc53c08e8..df9986940e9c 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1790,22 +1790,22 @@ static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, return secondary_ops->capget(target, effective, inheritable, permitted); } -static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective, +static int selinux_capset_check(kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted) { int error; - error = secondary_ops->capset_check(target, effective, inheritable, permitted); + error = secondary_ops->capset_check(effective, inheritable, permitted); if (error) return error; - return task_has_perm(current, target, PROCESS__SETCAP); + return task_has_perm(current, current, PROCESS__SETCAP); } -static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective, +static void selinux_capset_set(kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted) { - secondary_ops->capset_set(target, effective, inheritable, permitted); + secondary_ops->capset_set(effective, inheritable, permitted); } static int selinux_capable(struct task_struct *tsk, int cap, int audit) -- cgit v1.2.3 From 15a2460ed0af7538ca8e6c610fe607a2cd9da142 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:15 +1100 Subject: CRED: Constify the kernel_cap_t arguments to the capset LSM hooks Constify the kernel_cap_t arguments to the capset LSM hooks. Signed-off-by: David Howells Acked-by: Serge Hallyn Acked-by: James Morris Signed-off-by: James Morris --- include/linux/security.h | 44 ++++++++++++++++++++++++-------------------- security/commoncap.c | 10 ++++++---- security/security.c | 12 ++++++------ security/selinux/hooks.c | 10 ++++++---- 4 files changed, 42 insertions(+), 34 deletions(-) (limited to 'include') diff --git a/include/linux/security.h b/include/linux/security.h index d1ce8beddbd7..9f305d4a31a7 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -53,8 +53,12 @@ extern int cap_settime(struct timespec *ts, struct timezone *tz); extern int cap_ptrace_may_access(struct task_struct *child, unsigned int mode); extern int cap_ptrace_traceme(struct task_struct *parent); extern int cap_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); -extern int cap_capset_check(kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); -extern void cap_capset_set(kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); +extern int cap_capset_check(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted); +extern void cap_capset_set(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted); extern int cap_bprm_set_security(struct linux_binprm *bprm); extern void cap_bprm_apply_creds(struct linux_binprm *bprm, int unsafe); extern int cap_bprm_secureexec(struct linux_binprm *bprm); @@ -1293,12 +1297,12 @@ struct security_operations { int (*capget) (struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); - int (*capset_check) (kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted); - void (*capset_set) (kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted); + int (*capset_check) (const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted); + void (*capset_set) (const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted); int (*capable) (struct task_struct *tsk, int cap, int audit); int (*acct) (struct file *file); int (*sysctl) (struct ctl_table *table, int op); @@ -1560,12 +1564,12 @@ int security_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); -int security_capset_check(kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted); -void security_capset_set(kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted); +int security_capset_check(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted); +void security_capset_set(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted); int security_capable(struct task_struct *tsk, int cap); int security_capable_noaudit(struct task_struct *tsk, int cap); int security_acct(struct file *file); @@ -1755,16 +1759,16 @@ static inline int security_capget(struct task_struct *target, return cap_capget(target, effective, inheritable, permitted); } -static inline int security_capset_check(kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) +static inline int security_capset_check(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { return cap_capset_check(effective, inheritable, permitted); } -static inline void security_capset_set(kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) +static inline void security_capset_set(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { cap_capset_set(effective, inheritable, permitted); } diff --git a/security/commoncap.c b/security/commoncap.c index e3f36ef629fa..fb4e240720d8 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -118,8 +118,9 @@ static inline int cap_limit_ptraced_target(void) #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ -int cap_capset_check (kernel_cap_t *effective, - kernel_cap_t *inheritable, kernel_cap_t *permitted) +int cap_capset_check(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { if (cap_inh_is_capped() && !cap_issubset(*inheritable, @@ -150,8 +151,9 @@ int cap_capset_check (kernel_cap_t *effective, return 0; } -void cap_capset_set (kernel_cap_t *effective, - kernel_cap_t *inheritable, kernel_cap_t *permitted) +void cap_capset_set(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { current->cap_effective = *effective; current->cap_inheritable = *inheritable; diff --git a/security/security.c b/security/security.c index dca37381e2a7..81c956a12300 100644 --- a/security/security.c +++ b/security/security.c @@ -145,16 +145,16 @@ int security_capget(struct task_struct *target, return security_ops->capget(target, effective, inheritable, permitted); } -int security_capset_check(kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) +int security_capset_check(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { return security_ops->capset_check(effective, inheritable, permitted); } -void security_capset_set(kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) +void security_capset_set(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { security_ops->capset_set(effective, inheritable, permitted); } diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index df9986940e9c..9f6da154cc82 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1790,8 +1790,9 @@ static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, return secondary_ops->capget(target, effective, inheritable, permitted); } -static int selinux_capset_check(kernel_cap_t *effective, - kernel_cap_t *inheritable, kernel_cap_t *permitted) +static int selinux_capset_check(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { int error; @@ -1802,8 +1803,9 @@ static int selinux_capset_check(kernel_cap_t *effective, return task_has_perm(current, current, PROCESS__SETCAP); } -static void selinux_capset_set(kernel_cap_t *effective, - kernel_cap_t *inheritable, kernel_cap_t *permitted) +static void selinux_capset_set(const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { secondary_ops->capset_set(effective, inheritable, permitted); } -- cgit v1.2.3 From b6dff3ec5e116e3af6f537d4caedcad6b9e5082a Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:16 +1100 Subject: CRED: Separate task security context from task_struct Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne Signed-off-by: David Howells Acked-by: James Morris Acked-by: Serge Hallyn Signed-off-by: James Morris --- arch/alpha/kernel/asm-offsets.c | 11 +- arch/alpha/kernel/entry.S | 10 +- arch/ia64/ia32/sys_ia32.c | 8 +- arch/mips/kernel/kspd.c | 4 +- arch/s390/kernel/compat_linux.c | 28 ++--- drivers/connector/cn_proc.c | 8 +- fs/binfmt_elf.c | 12 +- fs/binfmt_elf_fdpic.c | 12 +- fs/exec.c | 4 +- fs/fcntl.c | 4 +- fs/file_table.c | 4 +- fs/fuse/dir.c | 12 +- fs/hugetlbfs/inode.c | 4 +- fs/ioprio.c | 12 +- fs/nfsd/auth.c | 22 ++-- fs/nfsd/nfs4recover.c | 12 +- fs/nfsd/nfsfh.c | 6 +- fs/open.c | 17 +-- fs/proc/array.c | 18 +-- fs/proc/base.c | 16 +-- fs/xfs/linux-2.6/xfs_cred.h | 6 +- fs/xfs/linux-2.6/xfs_globals.h | 2 +- fs/xfs/xfs_inode.h | 2 +- fs/xfs/xfs_vnodeops.h | 10 +- include/linux/cred.h | 155 +++++++++++++++++++---- include/linux/init_task.h | 24 ++-- include/linux/sched.h | 52 +------- include/linux/securebits.h | 2 +- ipc/mqueue.c | 2 +- ipc/shm.c | 4 +- kernel/auditsc.c | 52 ++++---- kernel/capability.c | 4 +- kernel/cgroup.c | 4 +- kernel/exit.c | 10 +- kernel/fork.c | 24 ++-- kernel/futex.c | 6 +- kernel/futex_compat.c | 5 +- kernel/ptrace.c | 19 +-- kernel/sched.c | 10 +- kernel/signal.c | 16 +-- kernel/sys.c | 266 ++++++++++++++++++++++----------------- kernel/trace/trace.c | 2 +- kernel/tsacct.c | 4 +- kernel/uid16.c | 28 ++--- kernel/user.c | 4 +- mm/mempolicy.c | 10 +- mm/migrate.c | 10 +- mm/oom_kill.c | 2 +- net/core/scm.c | 10 +- net/sunrpc/auth.c | 2 +- security/commoncap.c | 161 +++++++++++++----------- security/keys/keyctl.c | 25 ++-- security/keys/permission.c | 11 +- security/keys/process_keys.c | 98 ++++++++------- security/keys/request_key.c | 18 +-- security/keys/request_key_auth.c | 12 +- security/selinux/exports.c | 2 +- security/selinux/hooks.c | 116 ++++++++--------- security/selinux/selinuxfs.c | 2 +- security/selinux/xfrm.c | 6 +- security/smack/smack_access.c | 4 +- security/smack/smack_lsm.c | 77 ++++++------ security/smack/smackfs.c | 6 +- 63 files changed, 832 insertions(+), 677 deletions(-) (limited to 'include') diff --git a/arch/alpha/kernel/asm-offsets.c b/arch/alpha/kernel/asm-offsets.c index 4b18cd94d59d..6ff8886e7e22 100644 --- a/arch/alpha/kernel/asm-offsets.c +++ b/arch/alpha/kernel/asm-offsets.c @@ -19,15 +19,18 @@ void foo(void) BLANK(); DEFINE(TASK_BLOCKED, offsetof(struct task_struct, blocked)); - DEFINE(TASK_UID, offsetof(struct task_struct, uid)); - DEFINE(TASK_EUID, offsetof(struct task_struct, euid)); - DEFINE(TASK_GID, offsetof(struct task_struct, gid)); - DEFINE(TASK_EGID, offsetof(struct task_struct, egid)); + DEFINE(TASK_CRED, offsetof(struct task_struct, cred)); DEFINE(TASK_REAL_PARENT, offsetof(struct task_struct, real_parent)); DEFINE(TASK_GROUP_LEADER, offsetof(struct task_struct, group_leader)); DEFINE(TASK_TGID, offsetof(struct task_struct, tgid)); BLANK(); + DEFINE(CRED_UID, offsetof(struct cred, uid)); + DEFINE(CRED_EUID, offsetof(struct cred, euid)); + DEFINE(CRED_GID, offsetof(struct cred, gid)); + DEFINE(CRED_EGID, offsetof(struct cred, egid)); + BLANK(); + DEFINE(SIZEOF_PT_REGS, sizeof(struct pt_regs)); DEFINE(PT_PTRACED, PT_PTRACED); DEFINE(CLONE_VM, CLONE_VM); diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S index 5fc61e281ac7..f77345bc66a9 100644 --- a/arch/alpha/kernel/entry.S +++ b/arch/alpha/kernel/entry.S @@ -850,8 +850,9 @@ osf_getpriority: sys_getxuid: .prologue 0 ldq $2, TI_TASK($8) - ldl $0, TASK_UID($2) - ldl $1, TASK_EUID($2) + ldq $3, TASK_CRED($2) + ldl $0, CRED_UID($3) + ldl $1, CRED_EUID($3) stq $1, 80($sp) ret .end sys_getxuid @@ -862,8 +863,9 @@ sys_getxuid: sys_getxgid: .prologue 0 ldq $2, TI_TASK($8) - ldl $0, TASK_GID($2) - ldl $1, TASK_EGID($2) + ldq $3, TASK_CRED($2) + ldl $0, CRED_GID($3) + ldl $1, CRED_EGID($3) stq $1, 80($sp) ret .end sys_getxgid diff --git a/arch/ia64/ia32/sys_ia32.c b/arch/ia64/ia32/sys_ia32.c index 5e92ae00bdbb..2445a9d3488e 100644 --- a/arch/ia64/ia32/sys_ia32.c +++ b/arch/ia64/ia32/sys_ia32.c @@ -1772,20 +1772,20 @@ sys32_getgroups16 (int gidsetsize, short __user *grouplist) if (gidsetsize < 0) return -EINVAL; - get_group_info(current->group_info); - i = current->group_info->ngroups; + get_group_info(current->cred->group_info); + i = current->cred->group_info->ngroups; if (gidsetsize) { if (i > gidsetsize) { i = -EINVAL; goto out; } - if (groups16_to_user(grouplist, current->group_info)) { + if (groups16_to_user(grouplist, current->cred->group_info)) { i = -EFAULT; goto out; } } out: - put_group_info(current->group_info); + put_group_info(current->cred->group_info); return i; } diff --git a/arch/mips/kernel/kspd.c b/arch/mips/kernel/kspd.c index b0591ae0ce56..fd6e51224034 100644 --- a/arch/mips/kernel/kspd.c +++ b/arch/mips/kernel/kspd.c @@ -174,8 +174,8 @@ static unsigned int translate_open_flags(int flags) static void sp_setfsuidgid( uid_t uid, gid_t gid) { - current->fsuid = uid; - current->fsgid = gid; + current->cred->fsuid = uid; + current->cred->fsgid = gid; key_fsuid_changed(current); key_fsgid_changed(current); diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c index 4646382af34f..6cc87d8c8682 100644 --- a/arch/s390/kernel/compat_linux.c +++ b/arch/s390/kernel/compat_linux.c @@ -148,9 +148,9 @@ asmlinkage long sys32_getresuid16(u16 __user *ruid, u16 __user *euid, u16 __user { int retval; - if (!(retval = put_user(high2lowuid(current->uid), ruid)) && - !(retval = put_user(high2lowuid(current->euid), euid))) - retval = put_user(high2lowuid(current->suid), suid); + if (!(retval = put_user(high2lowuid(current->cred->uid), ruid)) && + !(retval = put_user(high2lowuid(current->cred->euid), euid))) + retval = put_user(high2lowuid(current->cred->suid), suid); return retval; } @@ -165,9 +165,9 @@ asmlinkage long sys32_getresgid16(u16 __user *rgid, u16 __user *egid, u16 __user { int retval; - if (!(retval = put_user(high2lowgid(current->gid), rgid)) && - !(retval = put_user(high2lowgid(current->egid), egid))) - retval = put_user(high2lowgid(current->sgid), sgid); + if (!(retval = put_user(high2lowgid(current->cred->gid), rgid)) && + !(retval = put_user(high2lowgid(current->cred->egid), egid))) + retval = put_user(high2lowgid(current->cred->sgid), sgid); return retval; } @@ -217,20 +217,20 @@ asmlinkage long sys32_getgroups16(int gidsetsize, u16 __user *grouplist) if (gidsetsize < 0) return -EINVAL; - get_group_info(current->group_info); - i = current->group_info->ngroups; + get_group_info(current->cred->group_info); + i = current->cred->group_info->ngroups; if (gidsetsize) { if (i > gidsetsize) { i = -EINVAL; goto out; } - if (groups16_to_user(grouplist, current->group_info)) { + if (groups16_to_user(grouplist, current->cred->group_info)) { i = -EFAULT; goto out; } } out: - put_group_info(current->group_info); + put_group_info(current->cred->group_info); return i; } @@ -261,22 +261,22 @@ asmlinkage long sys32_setgroups16(int gidsetsize, u16 __user *grouplist) asmlinkage long sys32_getuid16(void) { - return high2lowuid(current->uid); + return high2lowuid(current->cred->uid); } asmlinkage long sys32_geteuid16(void) { - return high2lowuid(current->euid); + return high2lowuid(current->cred->euid); } asmlinkage long sys32_getgid16(void) { - return high2lowgid(current->gid); + return high2lowgid(current->cred->gid); } asmlinkage long sys32_getegid16(void) { - return high2lowgid(current->egid); + return high2lowgid(current->cred->egid); } /* diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c index 5c9f67f98d10..354c1ff17159 100644 --- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -116,11 +116,11 @@ void proc_id_connector(struct task_struct *task, int which_id) ev->event_data.id.process_pid = task->pid; ev->event_data.id.process_tgid = task->tgid; if (which_id == PROC_EVENT_UID) { - ev->event_data.id.r.ruid = task->uid; - ev->event_data.id.e.euid = task->euid; + ev->event_data.id.r.ruid = task->cred->uid; + ev->event_data.id.e.euid = task->cred->euid; } else if (which_id == PROC_EVENT_GID) { - ev->event_data.id.r.rgid = task->gid; - ev->event_data.id.e.egid = task->egid; + ev->event_data.id.r.rgid = task->cred->gid; + ev->event_data.id.e.egid = task->cred->egid; } else return; get_seq(&msg->seq, &ev->cpu); diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 8fcfa398d350..7a52477ce493 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -223,10 +223,10 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, NEW_AUX_ENT(AT_BASE, interp_load_addr); NEW_AUX_ENT(AT_FLAGS, 0); NEW_AUX_ENT(AT_ENTRY, exec->e_entry); - NEW_AUX_ENT(AT_UID, tsk->uid); - NEW_AUX_ENT(AT_EUID, tsk->euid); - NEW_AUX_ENT(AT_GID, tsk->gid); - NEW_AUX_ENT(AT_EGID, tsk->egid); + NEW_AUX_ENT(AT_UID, tsk->cred->uid); + NEW_AUX_ENT(AT_EUID, tsk->cred->euid); + NEW_AUX_ENT(AT_GID, tsk->cred->gid); + NEW_AUX_ENT(AT_EGID, tsk->cred->egid); NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); NEW_AUX_ENT(AT_EXECFN, bprm->exec); if (k_platform) { @@ -1388,8 +1388,8 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, psinfo->pr_zomb = psinfo->pr_sname == 'Z'; psinfo->pr_nice = task_nice(p); psinfo->pr_flag = p->flags; - SET_UID(psinfo->pr_uid, p->uid); - SET_GID(psinfo->pr_gid, p->gid); + SET_UID(psinfo->pr_uid, p->cred->uid); + SET_GID(psinfo->pr_gid, p->cred->gid); strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); return 0; diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 488584c87512..9f67054c2c4e 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -623,10 +623,10 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); NEW_AUX_ENT(AT_FLAGS, 0); NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); - NEW_AUX_ENT(AT_UID, (elf_addr_t) current_uid()); - NEW_AUX_ENT(AT_EUID, (elf_addr_t) current_euid()); - NEW_AUX_ENT(AT_GID, (elf_addr_t) current_gid()); - NEW_AUX_ENT(AT_EGID, (elf_addr_t) current_egid()); + NEW_AUX_ENT(AT_UID, (elf_addr_t) current->cred->uid); + NEW_AUX_ENT(AT_EUID, (elf_addr_t) current->cred->euid); + NEW_AUX_ENT(AT_GID, (elf_addr_t) current->cred->gid); + NEW_AUX_ENT(AT_EGID, (elf_addr_t) current->cred->egid); NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); NEW_AUX_ENT(AT_EXECFN, bprm->exec); @@ -1440,8 +1440,8 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, psinfo->pr_zomb = psinfo->pr_sname == 'Z'; psinfo->pr_nice = task_nice(p); psinfo->pr_flag = p->flags; - SET_UID(psinfo->pr_uid, p->uid); - SET_GID(psinfo->pr_gid, p->gid); + SET_UID(psinfo->pr_uid, p->cred->uid); + SET_GID(psinfo->pr_gid, p->cred->gid); strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); return 0; diff --git a/fs/exec.c b/fs/exec.c index 604834f3b208..31149e430a89 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1738,7 +1738,7 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs) */ if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ flag = O_EXCL; /* Stop rewrite attacks */ - current->fsuid = 0; /* Dump root private */ + current->cred->fsuid = 0; /* Dump root private */ } retval = coredump_wait(exit_code, &core_state); @@ -1834,7 +1834,7 @@ fail_unlock: if (helper_argv) argv_free(helper_argv); - current->fsuid = fsuid; + current->cred->fsuid = fsuid; coredump_finish(mm); fail: return retval; diff --git a/fs/fcntl.c b/fs/fcntl.c index bf049a805e59..63964d863ad6 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -401,8 +401,8 @@ static inline int sigio_perm(struct task_struct *p, struct fown_struct *fown, int sig) { return (((fown->euid == 0) || - (fown->euid == p->suid) || (fown->euid == p->uid) || - (fown->uid == p->suid) || (fown->uid == p->uid)) && + (fown->euid == p->cred->suid) || (fown->euid == p->cred->uid) || + (fown->uid == p->cred->suid) || (fown->uid == p->cred->uid)) && !security_file_send_sigiotask(p, fown, sig)); } diff --git a/fs/file_table.c b/fs/file_table.c index 5ad0eca6eea2..3152b53cfab0 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -122,8 +122,8 @@ struct file *get_empty_filp(void) INIT_LIST_HEAD(&f->f_u.fu_list); atomic_long_set(&f->f_count, 1); rwlock_init(&f->f_owner.lock); - f->f_uid = tsk->fsuid; - f->f_gid = tsk->fsgid; + f->f_uid = tsk->cred->fsuid; + f->f_gid = tsk->cred->fsgid; eventpoll_init_file(f); /* f->f_version: 0 */ return f; diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index fd03330cadeb..e97a98981862 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -872,12 +872,12 @@ int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task) if (fc->flags & FUSE_ALLOW_OTHER) return 1; - if (task->euid == fc->user_id && - task->suid == fc->user_id && - task->uid == fc->user_id && - task->egid == fc->group_id && - task->sgid == fc->group_id && - task->gid == fc->group_id) + if (task->cred->euid == fc->user_id && + task->cred->suid == fc->user_id && + task->cred->uid == fc->user_id && + task->cred->egid == fc->group_id && + task->cred->sgid == fc->group_id && + task->cred->gid == fc->group_id) return 1; return 0; diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 08ad76c79b49..870a721b8bd2 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -958,7 +958,7 @@ struct file *hugetlb_file_setup(const char *name, size_t size) if (!can_do_hugetlb_shm()) return ERR_PTR(-EPERM); - if (!user_shm_lock(size, current->user)) + if (!user_shm_lock(size, current->cred->user)) return ERR_PTR(-ENOMEM); root = hugetlbfs_vfsmount->mnt_root; @@ -998,7 +998,7 @@ out_inode: out_dentry: dput(dentry); out_shm_unlock: - user_shm_unlock(size, current->user); + user_shm_unlock(size, current->cred->user); return ERR_PTR(error); } diff --git a/fs/ioprio.c b/fs/ioprio.c index 68d2cd807118..bb5210af77c2 100644 --- a/fs/ioprio.c +++ b/fs/ioprio.c @@ -32,8 +32,8 @@ static int set_task_ioprio(struct task_struct *task, int ioprio) int err; struct io_context *ioc; - if (task->uid != current_euid() && - task->uid != current_uid() && !capable(CAP_SYS_NICE)) + if (task->cred->uid != current_euid() && + task->cred->uid != current_uid() && !capable(CAP_SYS_NICE)) return -EPERM; err = security_task_setioprio(task, ioprio); @@ -123,7 +123,7 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio) break; case IOPRIO_WHO_USER: if (!who) - user = current->user; + user = current->cred->user; else user = find_user(who); @@ -131,7 +131,7 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio) break; do_each_thread(g, p) { - if (p->uid != who) + if (p->cred->uid != who) continue; ret = set_task_ioprio(p, ioprio); if (ret) @@ -216,7 +216,7 @@ asmlinkage long sys_ioprio_get(int which, int who) break; case IOPRIO_WHO_USER: if (!who) - user = current->user; + user = current->cred->user; else user = find_user(who); @@ -224,7 +224,7 @@ asmlinkage long sys_ioprio_get(int which, int who) break; do_each_thread(g, p) { - if (p->uid != user->uid) + if (p->cred->uid != user->uid) continue; tmpio = get_task_ioprio(p); if (tmpio < 0) diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c index 294992e9bf69..808fc03a6fbd 100644 --- a/fs/nfsd/auth.c +++ b/fs/nfsd/auth.c @@ -27,6 +27,7 @@ int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp) int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp) { + struct cred *act_as = current->cred ; struct svc_cred cred = rqstp->rq_cred; int i; int flags = nfsexp_flags(rqstp, exp); @@ -55,25 +56,26 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp) get_group_info(cred.cr_group_info); if (cred.cr_uid != (uid_t) -1) - current->fsuid = cred.cr_uid; + act_as->fsuid = cred.cr_uid; else - current->fsuid = exp->ex_anon_uid; + act_as->fsuid = exp->ex_anon_uid; if (cred.cr_gid != (gid_t) -1) - current->fsgid = cred.cr_gid; + act_as->fsgid = cred.cr_gid; else - current->fsgid = exp->ex_anon_gid; + act_as->fsgid = exp->ex_anon_gid; if (!cred.cr_group_info) return -ENOMEM; - ret = set_current_groups(cred.cr_group_info); + ret = set_groups(act_as, cred.cr_group_info); put_group_info(cred.cr_group_info); if ((cred.cr_uid)) { - current->cap_effective = - cap_drop_nfsd_set(current->cap_effective); + act_as->cap_effective = + cap_drop_nfsd_set(act_as->cap_effective); } else { - current->cap_effective = - cap_raise_nfsd_set(current->cap_effective, - current->cap_permitted); + act_as->cap_effective = + cap_raise_nfsd_set(act_as->cap_effective, + act_as->cap_permitted); } return ret; } + diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index bb93946ace22..a5e14e8695ea 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -57,17 +57,17 @@ static int rec_dir_init = 0; static void nfs4_save_user(uid_t *saveuid, gid_t *savegid) { - *saveuid = current->fsuid; - *savegid = current->fsgid; - current->fsuid = 0; - current->fsgid = 0; + *saveuid = current->cred->fsuid; + *savegid = current->cred->fsgid; + current->cred->fsuid = 0; + current->cred->fsgid = 0; } static void nfs4_reset_user(uid_t saveuid, gid_t savegid) { - current->fsuid = saveuid; - current->fsgid = savegid; + current->cred->fsuid = saveuid; + current->cred->fsgid = savegid; } static void diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c index cd25d91895a1..e67cfaea0865 100644 --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -186,9 +186,9 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp) * access control settings being in effect, we cannot * fix that case easily. */ - current->cap_effective = - cap_raise_nfsd_set(current->cap_effective, - current->cap_permitted); + current->cred->cap_effective = + cap_raise_nfsd_set(current->cred->cap_effective, + current->cred->cap_permitted); } else { error = nfsd_setuser_and_check_port(rqstp, exp); if (error) diff --git a/fs/open.c b/fs/open.c index 500cc0c54762..b1238e195e7e 100644 --- a/fs/open.c +++ b/fs/open.c @@ -425,6 +425,7 @@ out: */ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) { + struct cred *cred = current->cred; struct path path; struct inode *inode; int old_fsuid, old_fsgid; @@ -434,18 +435,18 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ return -EINVAL; - old_fsuid = current->fsuid; - old_fsgid = current->fsgid; + old_fsuid = cred->fsuid; + old_fsgid = cred->fsgid; - current->fsuid = current->uid; - current->fsgid = current->gid; + cred->fsuid = cred->uid; + cred->fsgid = cred->gid; if (!issecure(SECURE_NO_SETUID_FIXUP)) { /* Clear the capabilities if we switch to a non-root user */ - if (current->uid) + if (current->cred->uid) old_cap = cap_set_effective(__cap_empty_set); else - old_cap = cap_set_effective(current->cap_permitted); + old_cap = cap_set_effective(cred->cap_permitted); } res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); @@ -484,8 +485,8 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) out_path_release: path_put(&path); out: - current->fsuid = old_fsuid; - current->fsgid = old_fsgid; + cred->fsuid = old_fsuid; + cred->fsgid = old_fsgid; if (!issecure(SECURE_NO_SETUID_FIXUP)) cap_set_effective(old_cap); diff --git a/fs/proc/array.c b/fs/proc/array.c index 6af7fba7abb1..62fe9b2009b6 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -182,8 +182,8 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, task_tgid_nr_ns(p, ns), pid_nr_ns(pid, ns), ppid, tpid, - p->uid, p->euid, p->suid, p->fsuid, - p->gid, p->egid, p->sgid, p->fsgid); + p->cred->uid, p->cred->euid, p->cred->suid, p->cred->fsuid, + p->cred->gid, p->cred->egid, p->cred->sgid, p->cred->fsgid); task_lock(p); if (p->files) @@ -194,7 +194,7 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, fdt ? fdt->max_fds : 0); rcu_read_unlock(); - group_info = p->group_info; + group_info = p->cred->group_info; get_group_info(group_info); task_unlock(p); @@ -262,7 +262,7 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p) blocked = p->blocked; collect_sigign_sigcatch(p, &ignored, &caught); num_threads = atomic_read(&p->signal->count); - qsize = atomic_read(&p->user->sigpending); + qsize = atomic_read(&p->cred->user->sigpending); qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur; unlock_task_sighand(p, &flags); } @@ -293,10 +293,12 @@ static void render_cap_t(struct seq_file *m, const char *header, static inline void task_cap(struct seq_file *m, struct task_struct *p) { - render_cap_t(m, "CapInh:\t", &p->cap_inheritable); - render_cap_t(m, "CapPrm:\t", &p->cap_permitted); - render_cap_t(m, "CapEff:\t", &p->cap_effective); - render_cap_t(m, "CapBnd:\t", &p->cap_bset); + struct cred *cred = p->cred; + + render_cap_t(m, "CapInh:\t", &cred->cap_inheritable); + render_cap_t(m, "CapPrm:\t", &cred->cap_permitted); + render_cap_t(m, "CapEff:\t", &cred->cap_effective); + render_cap_t(m, "CapBnd:\t", &cred->cap_bset); } static inline void task_context_switch_counts(struct seq_file *m, diff --git a/fs/proc/base.c b/fs/proc/base.c index 486cf3fe7139..6862b360c36c 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1428,8 +1428,8 @@ static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_st inode->i_uid = 0; inode->i_gid = 0; if (task_dumpable(task)) { - inode->i_uid = task->euid; - inode->i_gid = task->egid; + inode->i_uid = task->cred->euid; + inode->i_gid = task->cred->egid; } security_task_to_inode(task, inode); @@ -1454,8 +1454,8 @@ static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat if (task) { if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || task_dumpable(task)) { - stat->uid = task->euid; - stat->gid = task->egid; + stat->uid = task->cred->euid; + stat->gid = task->cred->egid; } } rcu_read_unlock(); @@ -1486,8 +1486,8 @@ static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) if (task) { if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || task_dumpable(task)) { - inode->i_uid = task->euid; - inode->i_gid = task->egid; + inode->i_uid = task->cred->euid; + inode->i_gid = task->cred->egid; } else { inode->i_uid = 0; inode->i_gid = 0; @@ -1658,8 +1658,8 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) rcu_read_unlock(); put_files_struct(files); if (task_dumpable(task)) { - inode->i_uid = task->euid; - inode->i_gid = task->egid; + inode->i_uid = task->cred->euid; + inode->i_gid = task->cred->egid; } else { inode->i_uid = 0; inode->i_gid = 0; diff --git a/fs/xfs/linux-2.6/xfs_cred.h b/fs/xfs/linux-2.6/xfs_cred.h index 293043a5573a..8c022cd0ad67 100644 --- a/fs/xfs/linux-2.6/xfs_cred.h +++ b/fs/xfs/linux-2.6/xfs_cred.h @@ -23,11 +23,9 @@ /* * Credentials */ -typedef struct cred { - /* EMPTY */ -} cred_t; +typedef const struct cred cred_t; -extern struct cred *sys_cred; +extern cred_t *sys_cred; /* this is a hack.. (assumes sys_cred is the only cred_t in the system) */ static inline int capable_cred(cred_t *cr, int cid) diff --git a/fs/xfs/linux-2.6/xfs_globals.h b/fs/xfs/linux-2.6/xfs_globals.h index 2770b0085ee8..6eda8a3eb6f1 100644 --- a/fs/xfs/linux-2.6/xfs_globals.h +++ b/fs/xfs/linux-2.6/xfs_globals.h @@ -19,6 +19,6 @@ #define __XFS_GLOBALS_H__ extern uint64_t xfs_panic_mask; /* set to cause more panics */ -extern struct cred *sys_cred; +extern cred_t *sys_cred; #endif /* __XFS_GLOBALS_H__ */ diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index 1420c49674d7..6be310d41daf 100644 --- a/fs/xfs/xfs_inode.h +++ b/fs/xfs/xfs_inode.h @@ -497,7 +497,7 @@ int xfs_iread(struct xfs_mount *, struct xfs_trans *, xfs_ino_t, xfs_inode_t **, xfs_daddr_t, uint); int xfs_iread_extents(struct xfs_trans *, xfs_inode_t *, int); int xfs_ialloc(struct xfs_trans *, xfs_inode_t *, mode_t, - xfs_nlink_t, xfs_dev_t, struct cred *, xfs_prid_t, + xfs_nlink_t, xfs_dev_t, cred_t *, xfs_prid_t, int, struct xfs_buf **, boolean_t *, xfs_inode_t **); void xfs_dinode_from_disk(struct xfs_icdinode *, struct xfs_dinode_core *); diff --git a/fs/xfs/xfs_vnodeops.h b/fs/xfs/xfs_vnodeops.h index e932a96bec54..7b0c2ab88333 100644 --- a/fs/xfs/xfs_vnodeops.h +++ b/fs/xfs/xfs_vnodeops.h @@ -16,7 +16,7 @@ struct xfs_iomap; int xfs_open(struct xfs_inode *ip); int xfs_setattr(struct xfs_inode *ip, struct iattr *vap, int flags, - struct cred *credp); + cred_t *credp); #define XFS_ATTR_DMI 0x01 /* invocation from a DMI function */ #define XFS_ATTR_NONBLOCK 0x02 /* return EAGAIN if operation would block */ #define XFS_ATTR_NOLOCK 0x04 /* Don't grab any conflicting locks */ @@ -28,24 +28,24 @@ int xfs_inactive(struct xfs_inode *ip); int xfs_lookup(struct xfs_inode *dp, struct xfs_name *name, struct xfs_inode **ipp, struct xfs_name *ci_name); int xfs_create(struct xfs_inode *dp, struct xfs_name *name, mode_t mode, - xfs_dev_t rdev, struct xfs_inode **ipp, struct cred *credp); + xfs_dev_t rdev, struct xfs_inode **ipp, cred_t *credp); int xfs_remove(struct xfs_inode *dp, struct xfs_name *name, struct xfs_inode *ip); int xfs_link(struct xfs_inode *tdp, struct xfs_inode *sip, struct xfs_name *target_name); int xfs_mkdir(struct xfs_inode *dp, struct xfs_name *dir_name, - mode_t mode, struct xfs_inode **ipp, struct cred *credp); + mode_t mode, struct xfs_inode **ipp, cred_t *credp); int xfs_readdir(struct xfs_inode *dp, void *dirent, size_t bufsize, xfs_off_t *offset, filldir_t filldir); int xfs_symlink(struct xfs_inode *dp, struct xfs_name *link_name, const char *target_path, mode_t mode, struct xfs_inode **ipp, - struct cred *credp); + cred_t *credp); int xfs_inode_flush(struct xfs_inode *ip, int flags); int xfs_set_dmattrs(struct xfs_inode *ip, u_int evmask, u_int16_t state); int xfs_reclaim(struct xfs_inode *ip); int xfs_change_file_space(struct xfs_inode *ip, int cmd, xfs_flock64_t *bf, xfs_off_t offset, - struct cred *credp, int attr_flags); + cred_t *credp, int attr_flags); int xfs_rename(struct xfs_inode *src_dp, struct xfs_name *src_name, struct xfs_inode *src_ip, struct xfs_inode *target_dp, struct xfs_name *target_name, struct xfs_inode *target_ip); diff --git a/include/linux/cred.h b/include/linux/cred.h index b69222cc1fd2..3e65587a72e5 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -12,39 +12,150 @@ #ifndef _LINUX_CRED_H #define _LINUX_CRED_H -#define get_current_user() (get_uid(current->user)) - -#define task_uid(task) ((task)->uid) -#define task_gid(task) ((task)->gid) -#define task_euid(task) ((task)->euid) -#define task_egid(task) ((task)->egid) - -#define current_uid() (current->uid) -#define current_gid() (current->gid) -#define current_euid() (current->euid) -#define current_egid() (current->egid) -#define current_suid() (current->suid) -#define current_sgid() (current->sgid) -#define current_fsuid() (current->fsuid) -#define current_fsgid() (current->fsgid) -#define current_cap() (current->cap_effective) +#include +#include +#include + +struct user_struct; +struct cred; + +/* + * COW Supplementary groups list + */ +#define NGROUPS_SMALL 32 +#define NGROUPS_PER_BLOCK ((unsigned int)(PAGE_SIZE / sizeof(gid_t))) + +struct group_info { + atomic_t usage; + int ngroups; + int nblocks; + gid_t small_block[NGROUPS_SMALL]; + gid_t *blocks[0]; +}; + +/** + * get_group_info - Get a reference to a group info structure + * @group_info: The group info to reference + * + * This must be called with the owning task locked (via task_lock()) when task + * != current. The reason being that the vast majority of callers are looking + * at current->group_info, which can not be changed except by the current task. + * Changing current->group_info requires the task lock, too. + */ +#define get_group_info(group_info) \ +do { \ + atomic_inc(&(group_info)->usage); \ +} while (0) + +/** + * put_group_info - Release a reference to a group info structure + * @group_info: The group info to release + */ +#define put_group_info(group_info) \ +do { \ + if (atomic_dec_and_test(&(group_info)->usage)) \ + groups_free(group_info); \ +} while (0) + +extern struct group_info *groups_alloc(int); +extern void groups_free(struct group_info *); +extern int set_current_groups(struct group_info *); +extern int set_groups(struct cred *, struct group_info *); +extern int groups_search(struct group_info *, gid_t); + +/* access the groups "array" with this macro */ +#define GROUP_AT(gi, i) \ + ((gi)->blocks[(i) / NGROUPS_PER_BLOCK][(i) % NGROUPS_PER_BLOCK]) + +extern int in_group_p(gid_t); +extern int in_egroup_p(gid_t); + +/* + * The security context of a task + * + * The parts of the context break down into two categories: + * + * (1) The objective context of a task. These parts are used when some other + * task is attempting to affect this one. + * + * (2) The subjective context. These details are used when the task is acting + * upon another object, be that a file, a task, a key or whatever. + * + * Note that some members of this structure belong to both categories - the + * LSM security pointer for instance. + * + * A task has two security pointers. task->real_cred points to the objective + * context that defines that task's actual details. The objective part of this + * context is used whenever that task is acted upon. + * + * task->cred points to the subjective context that defines the details of how + * that task is going to act upon another object. This may be overridden + * temporarily to point to another security context, but normally points to the + * same context as task->real_cred. + */ +struct cred { + atomic_t usage; + uid_t uid; /* real UID of the task */ + gid_t gid; /* real GID of the task */ + uid_t suid; /* saved UID of the task */ + gid_t sgid; /* saved GID of the task */ + uid_t euid; /* effective UID of the task */ + gid_t egid; /* effective GID of the task */ + uid_t fsuid; /* UID for VFS ops */ + gid_t fsgid; /* GID for VFS ops */ + unsigned securebits; /* SUID-less security management */ + kernel_cap_t cap_inheritable; /* caps our children can inherit */ + kernel_cap_t cap_permitted; /* caps we're permitted */ + kernel_cap_t cap_effective; /* caps we can actually use */ + kernel_cap_t cap_bset; /* capability bounding set */ +#ifdef CONFIG_KEYS + unsigned char jit_keyring; /* default keyring to attach requested + * keys to */ + struct key *thread_keyring; /* keyring private to this thread */ + struct key *request_key_auth; /* assumed request_key authority */ +#endif +#ifdef CONFIG_SECURITY + void *security; /* subjective LSM security */ +#endif + struct user_struct *user; /* real user ID subscription */ + struct group_info *group_info; /* supplementary groups for euid/fsgid */ + struct rcu_head rcu; /* RCU deletion hook */ + spinlock_t lock; /* lock for pointer changes */ +}; + +#define get_current_user() (get_uid(current->cred->user)) + +#define task_uid(task) ((task)->cred->uid) +#define task_gid(task) ((task)->cred->gid) +#define task_euid(task) ((task)->cred->euid) +#define task_egid(task) ((task)->cred->egid) + +#define current_uid() (current->cred->uid) +#define current_gid() (current->cred->gid) +#define current_euid() (current->cred->euid) +#define current_egid() (current->cred->egid) +#define current_suid() (current->cred->suid) +#define current_sgid() (current->cred->sgid) +#define current_fsuid() (current->cred->fsuid) +#define current_fsgid() (current->cred->fsgid) +#define current_cap() (current->cred->cap_effective) #define current_uid_gid(_uid, _gid) \ do { \ - *(_uid) = current->uid; \ - *(_gid) = current->gid; \ + *(_uid) = current->cred->uid; \ + *(_gid) = current->cred->gid; \ } while(0) #define current_euid_egid(_uid, _gid) \ do { \ - *(_uid) = current->euid; \ - *(_gid) = current->egid; \ + *(_uid) = current->cred->euid; \ + *(_gid) = current->cred->egid; \ } while(0) #define current_fsuid_fsgid(_uid, _gid) \ do { \ - *(_uid) = current->fsuid; \ - *(_gid) = current->fsgid; \ + *(_uid) = current->cred->fsuid; \ + *(_gid) = current->cred->fsgid; \ } while(0) #endif /* _LINUX_CRED_H */ diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 23fd8909b9e5..9de41ccd67b5 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -113,6 +113,21 @@ extern struct group_info init_groups; # define CAP_INIT_BSET CAP_INIT_EFF_SET #endif +extern struct cred init_cred; + +#define INIT_CRED(p) \ +{ \ + .usage = ATOMIC_INIT(3), \ + .securebits = SECUREBITS_DEFAULT, \ + .cap_inheritable = CAP_INIT_INH_SET, \ + .cap_permitted = CAP_FULL_SET, \ + .cap_effective = CAP_INIT_EFF_SET, \ + .cap_bset = CAP_INIT_BSET, \ + .user = INIT_USER, \ + .group_info = &init_groups, \ + .lock = __SPIN_LOCK_UNLOCKED(p.lock), \ +} + /* * INIT_TASK is used to set up the first task table, touch at * your own risk!. Base=0, limit=0x1fffff (=2MB) @@ -147,13 +162,8 @@ extern struct group_info init_groups; .children = LIST_HEAD_INIT(tsk.children), \ .sibling = LIST_HEAD_INIT(tsk.sibling), \ .group_leader = &tsk, \ - .group_info = &init_groups, \ - .cap_effective = CAP_INIT_EFF_SET, \ - .cap_inheritable = CAP_INIT_INH_SET, \ - .cap_permitted = CAP_FULL_SET, \ - .cap_bset = CAP_INIT_BSET, \ - .securebits = SECUREBITS_DEFAULT, \ - .user = INIT_USER, \ + .__temp_cred = INIT_CRED(tsk.__temp_cred), \ + .cred = &tsk.__temp_cred, \ .comm = "swapper", \ .thread = INIT_THREAD, \ .fs = &init_fs, \ diff --git a/include/linux/sched.h b/include/linux/sched.h index b483f39a7112..c8b92502354d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -660,6 +660,7 @@ extern struct user_struct *find_user(uid_t); extern struct user_struct root_user; #define INIT_USER (&root_user) + struct backing_dev_info; struct reclaim_state; @@ -883,38 +884,7 @@ partition_sched_domains(int ndoms_new, cpumask_t *doms_new, #endif /* !CONFIG_SMP */ struct io_context; /* See blkdev.h */ -#define NGROUPS_SMALL 32 -#define NGROUPS_PER_BLOCK ((unsigned int)(PAGE_SIZE / sizeof(gid_t))) -struct group_info { - int ngroups; - atomic_t usage; - gid_t small_block[NGROUPS_SMALL]; - int nblocks; - gid_t *blocks[0]; -}; - -/* - * get_group_info() must be called with the owning task locked (via task_lock()) - * when task != current. The reason being that the vast majority of callers are - * looking at current->group_info, which can not be changed except by the - * current task. Changing current->group_info requires the task lock, too. - */ -#define get_group_info(group_info) do { \ - atomic_inc(&(group_info)->usage); \ -} while (0) -#define put_group_info(group_info) do { \ - if (atomic_dec_and_test(&(group_info)->usage)) \ - groups_free(group_info); \ -} while (0) - -extern struct group_info *groups_alloc(int gidsetsize); -extern void groups_free(struct group_info *group_info); -extern int set_current_groups(struct group_info *group_info); -extern int groups_search(struct group_info *group_info, gid_t grp); -/* access the groups "array" with this macro */ -#define GROUP_AT(gi, i) \ - ((gi)->blocks[(i)/NGROUPS_PER_BLOCK][(i)%NGROUPS_PER_BLOCK]) #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK extern void prefetch_stack(struct task_struct *t); @@ -1181,17 +1151,9 @@ struct task_struct { struct list_head cpu_timers[3]; /* process credentials */ - uid_t uid,euid,suid,fsuid; - gid_t gid,egid,sgid,fsgid; - struct group_info *group_info; - kernel_cap_t cap_effective, cap_inheritable, cap_permitted, cap_bset; - struct user_struct *user; - unsigned securebits; -#ifdef CONFIG_KEYS - unsigned char jit_keyring; /* default keyring to attach requested keys to */ - struct key *request_key_auth; /* assumed request_key authority */ - struct key *thread_keyring; /* keyring private to this thread */ -#endif + struct cred __temp_cred __deprecated; /* temporary credentials to be removed */ + struct cred *cred; /* actual/objective task credentials */ + char comm[TASK_COMM_LEN]; /* executable name excluding path - access with [gs]et_task_comm (which lock it with task_lock()) @@ -1228,9 +1190,6 @@ struct task_struct { int (*notifier)(void *priv); void *notifier_data; sigset_t *notifier_mask; -#ifdef CONFIG_SECURITY - void *security; -#endif struct audit_context *audit_context; #ifdef CONFIG_AUDITSYSCALL uid_t loginuid; @@ -1787,9 +1746,6 @@ extern void wake_up_new_task(struct task_struct *tsk, extern void sched_fork(struct task_struct *p, int clone_flags); extern void sched_dead(struct task_struct *p); -extern int in_group_p(gid_t); -extern int in_egroup_p(gid_t); - extern void proc_caches_init(void); extern void flush_signals(struct task_struct *); extern void ignore_signals(struct task_struct *); diff --git a/include/linux/securebits.h b/include/linux/securebits.h index 92f09bdf1175..6d389491bfa2 100644 --- a/include/linux/securebits.h +++ b/include/linux/securebits.h @@ -32,7 +32,7 @@ setting is locked or not. A setting which is locked cannot be changed from user-level. */ #define issecure_mask(X) (1 << (X)) -#define issecure(X) (issecure_mask(X) & current->securebits) +#define issecure(X) (issecure_mask(X) & current->cred->securebits) #define SECURE_ALL_BITS (issecure_mask(SECURE_NOROOT) | \ issecure_mask(SECURE_NO_SETUID_FIXUP) | \ diff --git a/ipc/mqueue.c b/ipc/mqueue.c index abda5991d7e3..e1885b494bac 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -126,7 +126,7 @@ static struct inode *mqueue_get_inode(struct super_block *sb, int mode, if (S_ISREG(mode)) { struct mqueue_inode_info *info; struct task_struct *p = current; - struct user_struct *u = p->user; + struct user_struct *u = p->cred->user; unsigned long mq_bytes, mq_msg_tblsz; inode->i_fop = &mqueue_file_operations; diff --git a/ipc/shm.c b/ipc/shm.c index 0c3debbe32d5..264a9d33c5dd 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -366,7 +366,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) if (shmflg & SHM_HUGETLB) { /* hugetlb_file_setup takes care of mlock user accounting */ file = hugetlb_file_setup(name, size); - shp->mlock_user = current->user; + shp->mlock_user = current->cred->user; } else { int acctflag = VM_ACCOUNT; /* @@ -767,7 +767,7 @@ asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf) goto out_unlock; if(cmd==SHM_LOCK) { - struct user_struct * user = current->user; + struct user_struct *user = current->cred->user; if (!is_file_hugepages(shp->shm_file)) { err = shmem_lock(shp->shm_file, 1, user); if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 9c7e47ae4576..2febf5165fad 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -447,6 +447,7 @@ static int audit_filter_rules(struct task_struct *tsk, struct audit_names *name, enum audit_state *state) { + struct cred *cred = tsk->cred; int i, j, need_sid = 1; u32 sid; @@ -466,28 +467,28 @@ static int audit_filter_rules(struct task_struct *tsk, } break; case AUDIT_UID: - result = audit_comparator(tsk->uid, f->op, f->val); + result = audit_comparator(cred->uid, f->op, f->val); break; case AUDIT_EUID: - result = audit_comparator(tsk->euid, f->op, f->val); + result = audit_comparator(cred->euid, f->op, f->val); break; case AUDIT_SUID: - result = audit_comparator(tsk->suid, f->op, f->val); + result = audit_comparator(cred->suid, f->op, f->val); break; case AUDIT_FSUID: - result = audit_comparator(tsk->fsuid, f->op, f->val); + result = audit_comparator(cred->fsuid, f->op, f->val); break; case AUDIT_GID: - result = audit_comparator(tsk->gid, f->op, f->val); + result = audit_comparator(cred->gid, f->op, f->val); break; case AUDIT_EGID: - result = audit_comparator(tsk->egid, f->op, f->val); + result = audit_comparator(cred->egid, f->op, f->val); break; case AUDIT_SGID: - result = audit_comparator(tsk->sgid, f->op, f->val); + result = audit_comparator(cred->sgid, f->op, f->val); break; case AUDIT_FSGID: - result = audit_comparator(tsk->fsgid, f->op, f->val); + result = audit_comparator(cred->fsgid, f->op, f->val); break; case AUDIT_PERS: result = audit_comparator(tsk->personality, f->op, f->val); @@ -1228,6 +1229,7 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) static void audit_log_exit(struct audit_context *context, struct task_struct *tsk) { + struct cred *cred = tsk->cred; int i, call_panic = 0; struct audit_buffer *ab; struct audit_aux_data *aux; @@ -1237,14 +1239,14 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts context->pid = tsk->pid; if (!context->ppid) context->ppid = sys_getppid(); - context->uid = tsk->uid; - context->gid = tsk->gid; - context->euid = tsk->euid; - context->suid = tsk->suid; - context->fsuid = tsk->fsuid; - context->egid = tsk->egid; - context->sgid = tsk->sgid; - context->fsgid = tsk->fsgid; + context->uid = cred->uid; + context->gid = cred->gid; + context->euid = cred->euid; + context->suid = cred->suid; + context->fsuid = cred->fsuid; + context->egid = cred->egid; + context->sgid = cred->sgid; + context->fsgid = cred->fsgid; context->personality = tsk->personality; ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL); @@ -2086,7 +2088,7 @@ int audit_set_loginuid(struct task_struct *task, uid_t loginuid) audit_log_format(ab, "login pid=%d uid=%u " "old auid=%u new auid=%u" " old ses=%u new ses=%u", - task->pid, task->uid, + task->pid, task->cred->uid, task->loginuid, loginuid, task->sessionid, sessionid); audit_log_end(ab); @@ -2469,7 +2471,7 @@ void __audit_ptrace(struct task_struct *t) context->target_pid = t->pid; context->target_auid = audit_get_loginuid(t); - context->target_uid = t->uid; + context->target_uid = t->cred->uid; context->target_sessionid = audit_get_sessionid(t); security_task_getsecid(t, &context->target_sid); memcpy(context->target_comm, t->comm, TASK_COMM_LEN); @@ -2495,7 +2497,7 @@ int __audit_signal_info(int sig, struct task_struct *t) if (tsk->loginuid != -1) audit_sig_uid = tsk->loginuid; else - audit_sig_uid = tsk->uid; + audit_sig_uid = tsk->cred->uid; security_task_getsecid(tsk, &audit_sig_sid); } if (!audit_signals || audit_dummy_context()) @@ -2507,7 +2509,7 @@ int __audit_signal_info(int sig, struct task_struct *t) if (!ctx->target_pid) { ctx->target_pid = t->tgid; ctx->target_auid = audit_get_loginuid(t); - ctx->target_uid = t->uid; + ctx->target_uid = t->cred->uid; ctx->target_sessionid = audit_get_sessionid(t); security_task_getsecid(t, &ctx->target_sid); memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN); @@ -2528,7 +2530,7 @@ int __audit_signal_info(int sig, struct task_struct *t) axp->target_pid[axp->pid_count] = t->tgid; axp->target_auid[axp->pid_count] = audit_get_loginuid(t); - axp->target_uid[axp->pid_count] = t->uid; + axp->target_uid[axp->pid_count] = t->cred->uid; axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t); security_task_getsecid(t, &axp->target_sid[axp->pid_count]); memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN); @@ -2575,12 +2577,12 @@ void __audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_ ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT; ax->old_pcap.permitted = *pP; - ax->old_pcap.inheritable = current->cap_inheritable; + ax->old_pcap.inheritable = current->cred->cap_inheritable; ax->old_pcap.effective = *pE; - ax->new_pcap.permitted = current->cap_permitted; - ax->new_pcap.inheritable = current->cap_inheritable; - ax->new_pcap.effective = current->cap_effective; + ax->new_pcap.permitted = current->cred->cap_permitted; + ax->new_pcap.inheritable = current->cred->cap_inheritable; + ax->new_pcap.effective = current->cred->cap_effective; } /** diff --git a/kernel/capability.c b/kernel/capability.c index 58b00519624a..a404b980b1bd 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -171,8 +171,8 @@ kernel_cap_t cap_set_effective(const kernel_cap_t pE_new) spin_lock(&task_capability_lock); - pE_old = current->cap_effective; - current->cap_effective = pE_new; + pE_old = current->cred->cap_effective; + current->cred->cap_effective = pE_new; spin_unlock(&task_capability_lock); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 78f9b310c4f3..e210526e6401 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1293,7 +1293,9 @@ static int attach_task_by_pid(struct cgroup *cgrp, u64 pid) rcu_read_unlock(); euid = current_euid(); - if (euid && euid != tsk->uid && euid != tsk->suid) { + if (euid && + euid != tsk->cred->uid && + euid != tsk->cred->suid) { put_task_struct(tsk); return -EACCES; } diff --git a/kernel/exit.c b/kernel/exit.c index 80137a5d9467..e0f6e1892fb9 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -160,7 +160,7 @@ void release_task(struct task_struct * p) int zap_leader; repeat: tracehook_prepare_release_task(p); - atomic_dec(&p->user->processes); + atomic_dec(&p->cred->user->processes); proc_flush_task(p); write_lock_irq(&tasklist_lock); tracehook_finish_release_task(p); @@ -1272,7 +1272,7 @@ static int wait_task_zombie(struct task_struct *p, int options, return 0; if (unlikely(options & WNOWAIT)) { - uid_t uid = p->uid; + uid_t uid = p->cred->uid; int exit_code = p->exit_code; int why, status; @@ -1393,7 +1393,7 @@ static int wait_task_zombie(struct task_struct *p, int options, if (!retval && infop) retval = put_user(pid, &infop->si_pid); if (!retval && infop) - retval = put_user(p->uid, &infop->si_uid); + retval = put_user(p->cred->uid, &infop->si_uid); if (!retval) retval = pid; @@ -1458,7 +1458,7 @@ static int wait_task_stopped(int ptrace, struct task_struct *p, if (!unlikely(options & WNOWAIT)) p->exit_code = 0; - uid = p->uid; + uid = p->cred->uid; unlock_sig: spin_unlock_irq(&p->sighand->siglock); if (!exit_code) @@ -1535,7 +1535,7 @@ static int wait_task_continued(struct task_struct *p, int options, spin_unlock_irq(&p->sighand->siglock); pid = task_pid_vnr(p); - uid = p->uid; + uid = p->cred->uid; get_task_struct(p); read_unlock(&tasklist_lock); diff --git a/kernel/fork.c b/kernel/fork.c index f6083561dfe0..81fdc7733908 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -147,8 +147,8 @@ void __put_task_struct(struct task_struct *tsk) WARN_ON(tsk == current); security_task_free(tsk); - free_uid(tsk->user); - put_group_info(tsk->group_info); + free_uid(tsk->__temp_cred.user); + put_group_info(tsk->__temp_cred.group_info); delayacct_tsk_free(tsk); if (!profile_handoff_task(tsk)) @@ -969,17 +969,18 @@ static struct task_struct *copy_process(unsigned long clone_flags, DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled); DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled); #endif + p->cred = &p->__temp_cred; retval = -EAGAIN; - if (atomic_read(&p->user->processes) >= + if (atomic_read(&p->cred->user->processes) >= p->signal->rlim[RLIMIT_NPROC].rlim_cur) { if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) && - p->user != current->nsproxy->user_ns->root_user) + p->cred->user != current->nsproxy->user_ns->root_user) goto bad_fork_free; } - atomic_inc(&p->user->__count); - atomic_inc(&p->user->processes); - get_group_info(p->group_info); + atomic_inc(&p->cred->user->__count); + atomic_inc(&p->cred->user->processes); + get_group_info(p->cred->group_info); /* * If multiple threads are within copy_process(), then this check @@ -1035,9 +1036,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->real_start_time = p->start_time; monotonic_to_bootbased(&p->real_start_time); #ifdef CONFIG_SECURITY - p->security = NULL; + p->cred->security = NULL; #endif - p->cap_bset = current->cap_bset; p->io_context = NULL; p->audit_context = NULL; cgroup_fork(p); @@ -1298,9 +1298,9 @@ bad_fork_cleanup_cgroup: bad_fork_cleanup_put_domain: module_put(task_thread_info(p)->exec_domain->module); bad_fork_cleanup_count: - put_group_info(p->group_info); - atomic_dec(&p->user->processes); - free_uid(p->user); + put_group_info(p->cred->group_info); + atomic_dec(&p->cred->user->processes); + free_uid(p->cred->user); bad_fork_free: free_task(p); fork_out: diff --git a/kernel/futex.c b/kernel/futex.c index e06962132aaf..28421d8210b8 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -443,7 +443,8 @@ static struct task_struct * futex_find_get_task(pid_t pid) rcu_read_lock(); p = find_task_by_vpid(pid); - if (!p || (euid != p->euid && euid != p->uid)) + if (!p || (euid != p->cred->euid && + euid != p->cred->uid)) p = ERR_PTR(-ESRCH); else get_task_struct(p); @@ -1846,7 +1847,8 @@ sys_get_robust_list(int pid, struct robust_list_head __user * __user *head_ptr, if (!p) goto err_unlock; ret = -EPERM; - if (euid != p->euid && euid != p->uid && + if (euid != p->cred->euid && + euid != p->cred->uid && !capable(CAP_SYS_PTRACE)) goto err_unlock; head = p->robust_list; diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c index 3254d4e41e88..2c3fd5ed34f5 100644 --- a/kernel/futex_compat.c +++ b/kernel/futex_compat.c @@ -151,8 +151,9 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, if (!p) goto err_unlock; ret = -EPERM; - if (euid != p->euid && euid != p->uid && - !capable(CAP_SYS_PTRACE)) + if (euid != p->cred->euid && + euid != p->cred->uid && + !capable(CAP_SYS_PTRACE)) goto err_unlock; head = p->compat_robust_list; read_unlock(&tasklist_lock); diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 937f6b5b2008..49849d12dd12 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -115,6 +115,8 @@ int ptrace_check_attach(struct task_struct *child, int kill) int __ptrace_may_access(struct task_struct *task, unsigned int mode) { + struct cred *cred = current->cred, *tcred = task->cred; + /* May we inspect the given task? * This check is used both for attaching with ptrace * and for allowing access to sensitive information in /proc. @@ -123,19 +125,18 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode) * because setting up the necessary parent/child relationship * or halting the specified task is impossible. */ - uid_t uid; - gid_t gid; + uid_t uid = cred->uid; + gid_t gid = cred->gid; int dumpable = 0; /* Don't let security modules deny introspection */ if (task == current) return 0; - current_uid_gid(&uid, &gid); - if ((uid != task->euid || - uid != task->suid || - uid != task->uid || - gid != task->egid || - gid != task->sgid || - gid != task->gid) && !capable(CAP_SYS_PTRACE)) + if ((uid != tcred->euid || + uid != tcred->suid || + uid != tcred->uid || + gid != tcred->egid || + gid != tcred->sgid || + gid != tcred->gid) && !capable(CAP_SYS_PTRACE)) return -EPERM; smp_rmb(); if (task->mm) diff --git a/kernel/sched.c b/kernel/sched.c index c3b8b1fcde0d..733c59e645aa 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -345,7 +345,7 @@ static inline struct task_group *task_group(struct task_struct *p) struct task_group *tg; #ifdef CONFIG_USER_SCHED - tg = p->user->tg; + tg = p->cred->user->tg; #elif defined(CONFIG_CGROUP_SCHED) tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), struct task_group, css); @@ -5182,8 +5182,8 @@ recheck: /* can't change other user's priorities */ euid = current_euid(); - if (euid != p->euid && - euid != p->uid) + if (euid != p->cred->euid && + euid != p->cred->uid) return -EPERM; } @@ -5417,7 +5417,9 @@ long sched_setaffinity(pid_t pid, const cpumask_t *in_mask) euid = current_euid(); retval = -EPERM; - if (euid != p->euid && euid != p->uid && !capable(CAP_SYS_NICE)) + if (euid != p->cred->euid && + euid != p->cred->uid && + !capable(CAP_SYS_NICE)) goto out_unlock; retval = security_task_setscheduler(p, 0, NULL); diff --git a/kernel/signal.c b/kernel/signal.c index 167b535fe1a9..80e8a6489f97 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -187,7 +187,7 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, * In order to avoid problems with "switch_user()", we want to make * sure that the compiler doesn't re-load "t->user" */ - user = t->user; + user = t->cred->user; barrier(); atomic_inc(&user->sigpending); if (override_rlimit || @@ -582,8 +582,8 @@ static int check_kill_permission(int sig, struct siginfo *info, uid = current_uid(); euid = current_euid(); - if ((euid ^ t->suid) && (euid ^ t->uid) && - (uid ^ t->suid) && (uid ^ t->uid) && + if ((euid ^ t->cred->suid) && (euid ^ t->cred->uid) && + (uid ^ t->cred->suid) && (uid ^ t->cred->uid) && !capable(CAP_KILL)) { switch (sig) { case SIGCONT: @@ -1100,8 +1100,8 @@ int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, goto out_unlock; } if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info))) - && (euid != p->suid) && (euid != p->uid) - && (uid != p->suid) && (uid != p->uid)) { + && (euid != p->cred->suid) && (euid != p->cred->uid) + && (uid != p->cred->suid) && (uid != p->cred->uid)) { ret = -EPERM; goto out_unlock; } @@ -1374,7 +1374,7 @@ int do_notify_parent(struct task_struct *tsk, int sig) info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); rcu_read_unlock(); - info.si_uid = tsk->uid; + info.si_uid = tsk->cred->uid; thread_group_cputime(tsk, &cputime); info.si_utime = cputime_to_jiffies(cputime.utime); @@ -1445,7 +1445,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, int why) info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); rcu_read_unlock(); - info.si_uid = tsk->uid; + info.si_uid = tsk->cred->uid; info.si_utime = cputime_to_clock_t(tsk->utime); info.si_stime = cputime_to_clock_t(tsk->stime); @@ -1713,7 +1713,7 @@ static int ptrace_signal(int signr, siginfo_t *info, info->si_errno = 0; info->si_code = SI_USER; info->si_pid = task_pid_vnr(current->parent); - info->si_uid = current->parent->uid; + info->si_uid = current->parent->cred->uid; } /* If the (new) signal is now blocked, requeue it. */ diff --git a/kernel/sys.c b/kernel/sys.c index ed5c29c748ac..5d81f07c0150 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -117,7 +117,9 @@ static int set_one_prio(struct task_struct *p, int niceval, int error) uid_t euid = current_euid(); int no_nice; - if (p->uid != euid && p->euid != euid && !capable(CAP_SYS_NICE)) { + if (p->cred->uid != euid && + p->cred->euid != euid && + !capable(CAP_SYS_NICE)) { error = -EPERM; goto out; } @@ -174,7 +176,7 @@ asmlinkage long sys_setpriority(int which, int who, int niceval) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: - user = current->user; + user = current->cred->user; if (!who) who = current_uid(); else @@ -182,7 +184,7 @@ asmlinkage long sys_setpriority(int which, int who, int niceval) goto out_unlock; /* No processes for this user */ do_each_thread(g, p) - if (p->uid == who) + if (p->cred->uid == who) error = set_one_prio(p, niceval, error); while_each_thread(g, p); if (who != current_uid()) @@ -236,7 +238,7 @@ asmlinkage long sys_getpriority(int which, int who) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: - user = current->user; + user = current->cred->user; if (!who) who = current_uid(); else @@ -244,7 +246,7 @@ asmlinkage long sys_getpriority(int which, int who) goto out_unlock; /* No processes for this user */ do_each_thread(g, p) - if (p->uid == who) { + if (p->cred->uid == who) { niceval = 20 - task_nice(p); if (niceval > retval) retval = niceval; @@ -472,8 +474,9 @@ void ctrl_alt_del(void) */ asmlinkage long sys_setregid(gid_t rgid, gid_t egid) { - int old_rgid = current->gid; - int old_egid = current->egid; + struct cred *cred = current->cred; + int old_rgid = cred->gid; + int old_egid = cred->egid; int new_rgid = old_rgid; int new_egid = old_egid; int retval; @@ -484,7 +487,7 @@ asmlinkage long sys_setregid(gid_t rgid, gid_t egid) if (rgid != (gid_t) -1) { if ((old_rgid == rgid) || - (current->egid==rgid) || + (cred->egid == rgid) || capable(CAP_SETGID)) new_rgid = rgid; else @@ -492,8 +495,8 @@ asmlinkage long sys_setregid(gid_t rgid, gid_t egid) } if (egid != (gid_t) -1) { if ((old_rgid == egid) || - (current->egid == egid) || - (current->sgid == egid) || + (cred->egid == egid) || + (cred->sgid == egid) || capable(CAP_SETGID)) new_egid = egid; else @@ -505,10 +508,10 @@ asmlinkage long sys_setregid(gid_t rgid, gid_t egid) } if (rgid != (gid_t) -1 || (egid != (gid_t) -1 && egid != old_rgid)) - current->sgid = new_egid; - current->fsgid = new_egid; - current->egid = new_egid; - current->gid = new_rgid; + cred->sgid = new_egid; + cred->fsgid = new_egid; + cred->egid = new_egid; + cred->gid = new_rgid; key_fsgid_changed(current); proc_id_connector(current, PROC_EVENT_GID); return 0; @@ -521,7 +524,8 @@ asmlinkage long sys_setregid(gid_t rgid, gid_t egid) */ asmlinkage long sys_setgid(gid_t gid) { - int old_egid = current->egid; + struct cred *cred = current->cred; + int old_egid = cred->egid; int retval; retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); @@ -533,13 +537,13 @@ asmlinkage long sys_setgid(gid_t gid) set_dumpable(current->mm, suid_dumpable); smp_wmb(); } - current->gid = current->egid = current->sgid = current->fsgid = gid; - } else if ((gid == current->gid) || (gid == current->sgid)) { + cred->gid = cred->egid = cred->sgid = cred->fsgid = gid; + } else if ((gid == cred->gid) || (gid == cred->sgid)) { if (old_egid != gid) { set_dumpable(current->mm, suid_dumpable); smp_wmb(); } - current->egid = current->fsgid = gid; + cred->egid = cred->fsgid = gid; } else return -EPERM; @@ -570,7 +574,7 @@ static int set_user(uid_t new_ruid, int dumpclear) set_dumpable(current->mm, suid_dumpable); smp_wmb(); } - current->uid = new_ruid; + current->cred->uid = new_ruid; return 0; } @@ -591,6 +595,7 @@ static int set_user(uid_t new_ruid, int dumpclear) */ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) { + struct cred *cred = current->cred; int old_ruid, old_euid, old_suid, new_ruid, new_euid; int retval; @@ -598,14 +603,14 @@ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) if (retval) return retval; - new_ruid = old_ruid = current->uid; - new_euid = old_euid = current->euid; - old_suid = current->suid; + new_ruid = old_ruid = cred->uid; + new_euid = old_euid = cred->euid; + old_suid = cred->suid; if (ruid != (uid_t) -1) { new_ruid = ruid; if ((old_ruid != ruid) && - (current->euid != ruid) && + (cred->euid != ruid) && !capable(CAP_SETUID)) return -EPERM; } @@ -613,8 +618,8 @@ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) if (euid != (uid_t) -1) { new_euid = euid; if ((old_ruid != euid) && - (current->euid != euid) && - (current->suid != euid) && + (cred->euid != euid) && + (cred->suid != euid) && !capable(CAP_SETUID)) return -EPERM; } @@ -626,11 +631,11 @@ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) set_dumpable(current->mm, suid_dumpable); smp_wmb(); } - current->fsuid = current->euid = new_euid; + cred->fsuid = cred->euid = new_euid; if (ruid != (uid_t) -1 || (euid != (uid_t) -1 && euid != old_ruid)) - current->suid = current->euid; - current->fsuid = current->euid; + cred->suid = cred->euid; + cred->fsuid = cred->euid; key_fsuid_changed(current); proc_id_connector(current, PROC_EVENT_UID); @@ -653,7 +658,8 @@ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) */ asmlinkage long sys_setuid(uid_t uid) { - int old_euid = current->euid; + struct cred *cred = current->cred; + int old_euid = cred->euid; int old_ruid, old_suid, new_suid; int retval; @@ -661,23 +667,23 @@ asmlinkage long sys_setuid(uid_t uid) if (retval) return retval; - old_ruid = current->uid; - old_suid = current->suid; + old_ruid = cred->uid; + old_suid = cred->suid; new_suid = old_suid; if (capable(CAP_SETUID)) { if (uid != old_ruid && set_user(uid, old_euid != uid) < 0) return -EAGAIN; new_suid = uid; - } else if ((uid != current->uid) && (uid != new_suid)) + } else if ((uid != cred->uid) && (uid != new_suid)) return -EPERM; if (old_euid != uid) { set_dumpable(current->mm, suid_dumpable); smp_wmb(); } - current->fsuid = current->euid = uid; - current->suid = new_suid; + cred->fsuid = cred->euid = uid; + cred->suid = new_suid; key_fsuid_changed(current); proc_id_connector(current, PROC_EVENT_UID); @@ -692,9 +698,10 @@ asmlinkage long sys_setuid(uid_t uid) */ asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) { - int old_ruid = current->uid; - int old_euid = current->euid; - int old_suid = current->suid; + struct cred *cred = current->cred; + int old_ruid = cred->uid; + int old_euid = cred->euid; + int old_suid = cred->suid; int retval; retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES); @@ -702,30 +709,31 @@ asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) return retval; if (!capable(CAP_SETUID)) { - if ((ruid != (uid_t) -1) && (ruid != current->uid) && - (ruid != current->euid) && (ruid != current->suid)) + if ((ruid != (uid_t) -1) && (ruid != cred->uid) && + (ruid != cred->euid) && (ruid != cred->suid)) return -EPERM; - if ((euid != (uid_t) -1) && (euid != current->uid) && - (euid != current->euid) && (euid != current->suid)) + if ((euid != (uid_t) -1) && (euid != cred->uid) && + (euid != cred->euid) && (euid != cred->suid)) return -EPERM; - if ((suid != (uid_t) -1) && (suid != current->uid) && - (suid != current->euid) && (suid != current->suid)) + if ((suid != (uid_t) -1) && (suid != cred->uid) && + (suid != cred->euid) && (suid != cred->suid)) return -EPERM; } if (ruid != (uid_t) -1) { - if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0) + if (ruid != cred->uid && + set_user(ruid, euid != cred->euid) < 0) return -EAGAIN; } if (euid != (uid_t) -1) { - if (euid != current->euid) { + if (euid != cred->euid) { set_dumpable(current->mm, suid_dumpable); smp_wmb(); } - current->euid = euid; + cred->euid = euid; } - current->fsuid = current->euid; + cred->fsuid = cred->euid; if (suid != (uid_t) -1) - current->suid = suid; + cred->suid = suid; key_fsuid_changed(current); proc_id_connector(current, PROC_EVENT_UID); @@ -735,11 +743,12 @@ asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid) { + struct cred *cred = current->cred; int retval; - if (!(retval = put_user(current->uid, ruid)) && - !(retval = put_user(current->euid, euid))) - retval = put_user(current->suid, suid); + if (!(retval = put_user(cred->uid, ruid)) && + !(retval = put_user(cred->euid, euid))) + retval = put_user(cred->suid, suid); return retval; } @@ -749,6 +758,7 @@ asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __us */ asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) { + struct cred *cred = current->cred; int retval; retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES); @@ -756,28 +766,28 @@ asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) return retval; if (!capable(CAP_SETGID)) { - if ((rgid != (gid_t) -1) && (rgid != current->gid) && - (rgid != current->egid) && (rgid != current->sgid)) + if ((rgid != (gid_t) -1) && (rgid != cred->gid) && + (rgid != cred->egid) && (rgid != cred->sgid)) return -EPERM; - if ((egid != (gid_t) -1) && (egid != current->gid) && - (egid != current->egid) && (egid != current->sgid)) + if ((egid != (gid_t) -1) && (egid != cred->gid) && + (egid != cred->egid) && (egid != cred->sgid)) return -EPERM; - if ((sgid != (gid_t) -1) && (sgid != current->gid) && - (sgid != current->egid) && (sgid != current->sgid)) + if ((sgid != (gid_t) -1) && (sgid != cred->gid) && + (sgid != cred->egid) && (sgid != cred->sgid)) return -EPERM; } if (egid != (gid_t) -1) { - if (egid != current->egid) { + if (egid != cred->egid) { set_dumpable(current->mm, suid_dumpable); smp_wmb(); } - current->egid = egid; + cred->egid = egid; } - current->fsgid = current->egid; + cred->fsgid = cred->egid; if (rgid != (gid_t) -1) - current->gid = rgid; + cred->gid = rgid; if (sgid != (gid_t) -1) - current->sgid = sgid; + cred->sgid = sgid; key_fsgid_changed(current); proc_id_connector(current, PROC_EVENT_GID); @@ -786,11 +796,12 @@ asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid) { + struct cred *cred = current->cred; int retval; - if (!(retval = put_user(current->gid, rgid)) && - !(retval = put_user(current->egid, egid))) - retval = put_user(current->sgid, sgid); + if (!(retval = put_user(cred->gid, rgid)) && + !(retval = put_user(cred->egid, egid))) + retval = put_user(cred->sgid, sgid); return retval; } @@ -804,20 +815,21 @@ asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __us */ asmlinkage long sys_setfsuid(uid_t uid) { + struct cred *cred = current->cred; int old_fsuid; - old_fsuid = current->fsuid; + old_fsuid = cred->fsuid; if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS)) return old_fsuid; - if (uid == current->uid || uid == current->euid || - uid == current->suid || uid == current->fsuid || + if (uid == cred->uid || uid == cred->euid || + uid == cred->suid || uid == cred->fsuid || capable(CAP_SETUID)) { if (uid != old_fsuid) { set_dumpable(current->mm, suid_dumpable); smp_wmb(); } - current->fsuid = uid; + cred->fsuid = uid; } key_fsuid_changed(current); @@ -833,20 +845,21 @@ asmlinkage long sys_setfsuid(uid_t uid) */ asmlinkage long sys_setfsgid(gid_t gid) { + struct cred *cred = current->cred; int old_fsgid; - old_fsgid = current->fsgid; + old_fsgid = cred->fsgid; if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS)) return old_fsgid; - if (gid == current->gid || gid == current->egid || - gid == current->sgid || gid == current->fsgid || + if (gid == cred->gid || gid == cred->egid || + gid == cred->sgid || gid == cred->fsgid || capable(CAP_SETGID)) { if (gid != old_fsgid) { set_dumpable(current->mm, suid_dumpable); smp_wmb(); } - current->fsgid = gid; + cred->fsgid = gid; key_fsgid_changed(current); proc_id_connector(current, PROC_EVENT_GID); } @@ -1208,8 +1221,15 @@ int groups_search(struct group_info *group_info, gid_t grp) return 0; } -/* validate and set current->group_info */ -int set_current_groups(struct group_info *group_info) +/** + * set_groups - Change a group subscription in a security record + * @sec: The security record to alter + * @group_info: The group list to impose + * + * Validate a group subscription and, if valid, impose it upon a task security + * record. + */ +int set_groups(struct cred *cred, struct group_info *group_info) { int retval; struct group_info *old_info; @@ -1221,20 +1241,34 @@ int set_current_groups(struct group_info *group_info) groups_sort(group_info); get_group_info(group_info); - task_lock(current); - old_info = current->group_info; - current->group_info = group_info; - task_unlock(current); + spin_lock(&cred->lock); + old_info = cred->group_info; + cred->group_info = group_info; + spin_unlock(&cred->lock); put_group_info(old_info); - return 0; } +EXPORT_SYMBOL(set_groups); + +/** + * set_current_groups - Change current's group subscription + * @group_info: The group list to impose + * + * Validate a group subscription and, if valid, impose it upon current's task + * security record. + */ +int set_current_groups(struct group_info *group_info) +{ + return set_groups(current->cred, group_info); +} + EXPORT_SYMBOL(set_current_groups); asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist) { + struct cred *cred = current->cred; int i = 0; /* @@ -1246,13 +1280,13 @@ asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist) return -EINVAL; /* no need to grab task_lock here; it cannot change */ - i = current->group_info->ngroups; + i = cred->group_info->ngroups; if (gidsetsize) { if (i > gidsetsize) { i = -EINVAL; goto out; } - if (groups_to_user(grouplist, current->group_info)) { + if (groups_to_user(grouplist, cred->group_info)) { i = -EFAULT; goto out; } @@ -1296,9 +1330,10 @@ asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist) */ int in_group_p(gid_t grp) { + struct cred *cred = current->cred; int retval = 1; - if (grp != current->fsgid) - retval = groups_search(current->group_info, grp); + if (grp != cred->fsgid) + retval = groups_search(cred->group_info, grp); return retval; } @@ -1306,9 +1341,10 @@ EXPORT_SYMBOL(in_group_p); int in_egroup_p(gid_t grp) { + struct cred *cred = current->cred; int retval = 1; - if (grp != current->egid) - retval = groups_search(current->group_info, grp); + if (grp != cred->egid) + retval = groups_search(cred->group_info, grp); return retval; } @@ -1624,7 +1660,9 @@ asmlinkage long sys_umask(int mask) asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { - long error = 0; + struct task_struct *me = current; + unsigned char comm[sizeof(me->comm)]; + long error; if (security_task_prctl(option, arg2, arg3, arg4, arg5, &error)) return error; @@ -1635,39 +1673,41 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, error = -EINVAL; break; } - current->pdeath_signal = arg2; + me->pdeath_signal = arg2; + error = 0; break; case PR_GET_PDEATHSIG: - error = put_user(current->pdeath_signal, (int __user *)arg2); + error = put_user(me->pdeath_signal, (int __user *)arg2); break; case PR_GET_DUMPABLE: - error = get_dumpable(current->mm); + error = get_dumpable(me->mm); break; case PR_SET_DUMPABLE: if (arg2 < 0 || arg2 > 1) { error = -EINVAL; break; } - set_dumpable(current->mm, arg2); + set_dumpable(me->mm, arg2); + error = 0; break; case PR_SET_UNALIGN: - error = SET_UNALIGN_CTL(current, arg2); + error = SET_UNALIGN_CTL(me, arg2); break; case PR_GET_UNALIGN: - error = GET_UNALIGN_CTL(current, arg2); + error = GET_UNALIGN_CTL(me, arg2); break; case PR_SET_FPEMU: - error = SET_FPEMU_CTL(current, arg2); + error = SET_FPEMU_CTL(me, arg2); break; case PR_GET_FPEMU: - error = GET_FPEMU_CTL(current, arg2); + error = GET_FPEMU_CTL(me, arg2); break; case PR_SET_FPEXC: - error = SET_FPEXC_CTL(current, arg2); + error = SET_FPEXC_CTL(me, arg2); break; case PR_GET_FPEXC: - error = GET_FPEXC_CTL(current, arg2); + error = GET_FPEXC_CTL(me, arg2); break; case PR_GET_TIMING: error = PR_TIMING_STATISTICAL; @@ -1675,33 +1715,28 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, case PR_SET_TIMING: if (arg2 != PR_TIMING_STATISTICAL) error = -EINVAL; + else + error = 0; break; - case PR_SET_NAME: { - struct task_struct *me = current; - unsigned char ncomm[sizeof(me->comm)]; - - ncomm[sizeof(me->comm)-1] = 0; - if (strncpy_from_user(ncomm, (char __user *)arg2, - sizeof(me->comm)-1) < 0) + case PR_SET_NAME: + comm[sizeof(me->comm)-1] = 0; + if (strncpy_from_user(comm, (char __user *)arg2, + sizeof(me->comm) - 1) < 0) return -EFAULT; - set_task_comm(me, ncomm); + set_task_comm(me, comm); return 0; - } - case PR_GET_NAME: { - struct task_struct *me = current; - unsigned char tcomm[sizeof(me->comm)]; - - get_task_comm(tcomm, me); - if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm))) + case PR_GET_NAME: + get_task_comm(comm, me); + if (copy_to_user((char __user *)arg2, comm, + sizeof(comm))) return -EFAULT; return 0; - } case PR_GET_ENDIAN: - error = GET_ENDIAN(current, arg2); + error = GET_ENDIAN(me, arg2); break; case PR_SET_ENDIAN: - error = SET_ENDIAN(current, arg2); + error = SET_ENDIAN(me, arg2); break; case PR_GET_SECCOMP: @@ -1725,6 +1760,7 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, current->default_timer_slack_ns; else current->timer_slack_ns = arg2; + error = 0; break; default: error = -EINVAL; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 9f3b478f9171..5c97c5b4ea8f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -246,7 +246,7 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) memcpy(data->comm, tsk->comm, TASK_COMM_LEN); data->pid = tsk->pid; - data->uid = tsk->uid; + data->uid = task_uid(tsk); data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; data->policy = tsk->policy; data->rt_priority = tsk->rt_priority; diff --git a/kernel/tsacct.c b/kernel/tsacct.c index 8ebcd8532dfb..6d1ed07bf312 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -53,8 +53,8 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk) stats->ac_flag |= AXSIG; stats->ac_nice = task_nice(tsk); stats->ac_sched = tsk->policy; - stats->ac_uid = tsk->uid; - stats->ac_gid = tsk->gid; + stats->ac_uid = tsk->cred->uid; + stats->ac_gid = tsk->cred->gid; stats->ac_pid = tsk->pid; rcu_read_lock(); stats->ac_ppid = pid_alive(tsk) ? diff --git a/kernel/uid16.c b/kernel/uid16.c index 3e41c1673e2f..71f07fc39fea 100644 --- a/kernel/uid16.c +++ b/kernel/uid16.c @@ -86,9 +86,9 @@ asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, { int retval; - if (!(retval = put_user(high2lowuid(current->uid), ruid)) && - !(retval = put_user(high2lowuid(current->euid), euid))) - retval = put_user(high2lowuid(current->suid), suid); + if (!(retval = put_user(high2lowuid(current->cred->uid), ruid)) && + !(retval = put_user(high2lowuid(current->cred->euid), euid))) + retval = put_user(high2lowuid(current->cred->suid), suid); return retval; } @@ -106,9 +106,9 @@ asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, { int retval; - if (!(retval = put_user(high2lowgid(current->gid), rgid)) && - !(retval = put_user(high2lowgid(current->egid), egid))) - retval = put_user(high2lowgid(current->sgid), sgid); + if (!(retval = put_user(high2lowgid(current->cred->gid), rgid)) && + !(retval = put_user(high2lowgid(current->cred->egid), egid))) + retval = put_user(high2lowgid(current->cred->sgid), sgid); return retval; } @@ -166,20 +166,20 @@ asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist) if (gidsetsize < 0) return -EINVAL; - get_group_info(current->group_info); - i = current->group_info->ngroups; + get_group_info(current->cred->group_info); + i = current->cred->group_info->ngroups; if (gidsetsize) { if (i > gidsetsize) { i = -EINVAL; goto out; } - if (groups16_to_user(grouplist, current->group_info)) { + if (groups16_to_user(grouplist, current->cred->group_info)) { i = -EFAULT; goto out; } } out: - put_group_info(current->group_info); + put_group_info(current->cred->group_info); return i; } @@ -210,20 +210,20 @@ asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist) asmlinkage long sys_getuid16(void) { - return high2lowuid(current->uid); + return high2lowuid(current->cred->uid); } asmlinkage long sys_geteuid16(void) { - return high2lowuid(current->euid); + return high2lowuid(current->cred->euid); } asmlinkage long sys_getgid16(void) { - return high2lowgid(current->gid); + return high2lowgid(current->cred->gid); } asmlinkage long sys_getegid16(void) { - return high2lowgid(current->egid); + return high2lowgid(current->cred->egid); } diff --git a/kernel/user.c b/kernel/user.c index 39d6159fae43..104d22ac84d5 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -457,11 +457,11 @@ void switch_uid(struct user_struct *new_user) * cheaply with the new uid cache, so if it matters * we should be checking for it. -DaveM */ - old_user = current->user; + old_user = current->cred->user; atomic_inc(&new_user->processes); atomic_dec(&old_user->processes); switch_uid_keyring(new_user); - current->user = new_user; + current->cred->user = new_user; sched_switch_user(current); /* diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 07a96474077d..b23492ee3e50 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1110,12 +1110,12 @@ asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode, const unsigned long __user *old_nodes, const unsigned long __user *new_nodes) { + struct cred *cred, *tcred; struct mm_struct *mm; struct task_struct *task; nodemask_t old; nodemask_t new; nodemask_t task_nodes; - uid_t uid, euid; int err; err = get_nodes(&old, old_nodes, maxnode); @@ -1145,10 +1145,10 @@ asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode, * capabilities, superuser privileges or the same * userid as the target process. */ - uid = current_uid(); - euid = current_euid(); - if (euid != task->suid && euid != task->uid && - uid != task->suid && uid != task->uid && + cred = current->cred; + tcred = task->cred; + if (cred->euid != tcred->suid && cred->euid != tcred->uid && + cred->uid != tcred->suid && cred->uid != tcred->uid && !capable(CAP_SYS_NICE)) { err = -EPERM; goto out; diff --git a/mm/migrate.c b/mm/migrate.c index 6263c24c4afe..794443da1b4f 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1045,10 +1045,10 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages, const int __user *nodes, int __user *status, int flags) { + struct cred *cred, *tcred; struct task_struct *task; struct mm_struct *mm; int err; - uid_t uid, euid; /* Check flags */ if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL)) @@ -1076,10 +1076,10 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages, * capabilities, superuser privileges or the same * userid as the target process. */ - uid = current_uid(); - euid = current_euid(); - if (euid != task->suid && euid != task->uid && - uid != task->suid && uid != task->uid && + cred = current->cred; + tcred = task->cred; + if (cred->euid != tcred->suid && cred->euid != tcred->uid && + cred->uid != tcred->suid && cred->uid != tcred->uid && !capable(CAP_SYS_NICE)) { err = -EPERM; goto out; diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 34a458aa7997..3af787ba2077 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -298,7 +298,7 @@ static void dump_tasks(const struct mem_cgroup *mem) task_lock(p); printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d %3d %s\n", - p->pid, p->uid, p->tgid, p->mm->total_vm, + p->pid, p->cred->uid, p->tgid, p->mm->total_vm, get_mm_rss(p->mm), (int)task_cpu(p), p->oomkilladj, p->comm); task_unlock(p); diff --git a/net/core/scm.c b/net/core/scm.c index 4681d8f9b45b..c28ca32a7d93 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -44,11 +44,13 @@ static __inline__ int scm_check_creds(struct ucred *creds) { + struct cred *cred = current->cred; + if ((creds->pid == task_tgid_vnr(current) || capable(CAP_SYS_ADMIN)) && - ((creds->uid == current_uid() || creds->uid == current_euid() || - creds->uid == current_suid()) || capable(CAP_SETUID)) && - ((creds->gid == current_gid() || creds->gid == current_egid() || - creds->gid == current_sgid()) || capable(CAP_SETGID))) { + ((creds->uid == cred->uid || creds->uid == cred->euid || + creds->uid == cred->suid) || capable(CAP_SETUID)) && + ((creds->gid == cred->gid || creds->gid == cred->egid || + creds->gid == cred->sgid) || capable(CAP_SETGID))) { return 0; } return -EPERM; diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index 8fc380578807..c79543212602 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -353,7 +353,7 @@ rpcauth_lookupcred(struct rpc_auth *auth, int flags) struct auth_cred acred = { .uid = current_fsuid(), .gid = current_fsgid(), - .group_info = current->group_info, + .group_info = current->cred->group_info, }; struct rpc_cred *ret; diff --git a/security/commoncap.c b/security/commoncap.c index fb4e240720d8..fa61679f8c73 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -30,7 +30,7 @@ int cap_netlink_send(struct sock *sk, struct sk_buff *skb) { - NETLINK_CB(skb).eff_cap = current->cap_effective; + NETLINK_CB(skb).eff_cap = current_cap(); return 0; } @@ -52,7 +52,7 @@ EXPORT_SYMBOL(cap_netlink_recv); int cap_capable(struct task_struct *tsk, int cap, int audit) { /* Derived from include/linux/sched.h:capable. */ - if (cap_raised(tsk->cap_effective, cap)) + if (cap_raised(tsk->cred->cap_effective, cap)) return 0; return -EPERM; } @@ -67,7 +67,8 @@ int cap_settime(struct timespec *ts, struct timezone *tz) int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) { /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ - if (cap_issubset(child->cap_permitted, current->cap_permitted)) + if (cap_issubset(child->cred->cap_permitted, + current->cred->cap_permitted)) return 0; if (capable(CAP_SYS_PTRACE)) return 0; @@ -76,8 +77,8 @@ int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) int cap_ptrace_traceme(struct task_struct *parent) { - /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ - if (cap_issubset(current->cap_permitted, parent->cap_permitted)) + if (cap_issubset(current->cred->cap_permitted, + parent->cred->cap_permitted)) return 0; if (has_capability(parent, CAP_SYS_PTRACE)) return 0; @@ -87,10 +88,12 @@ int cap_ptrace_traceme(struct task_struct *parent) int cap_capget (struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted) { + struct cred *cred = target->cred; + /* Derived from kernel/capability.c:sys_capget. */ - *effective = target->cap_effective; - *inheritable = target->cap_inheritable; - *permitted = target->cap_permitted; + *effective = cred->cap_effective; + *inheritable = cred->cap_inheritable; + *permitted = cred->cap_permitted; return 0; } @@ -122,24 +125,26 @@ int cap_capset_check(const kernel_cap_t *effective, const kernel_cap_t *inheritable, const kernel_cap_t *permitted) { + const struct cred *cred = current->cred; + if (cap_inh_is_capped() && !cap_issubset(*inheritable, - cap_combine(current->cap_inheritable, - current->cap_permitted))) { + cap_combine(cred->cap_inheritable, + cred->cap_permitted))) { /* incapable of using this inheritable set */ return -EPERM; } if (!cap_issubset(*inheritable, - cap_combine(current->cap_inheritable, - current->cap_bset))) { + cap_combine(cred->cap_inheritable, + cred->cap_bset))) { /* no new pI capabilities outside bounding set */ return -EPERM; } /* verify restrictions on target's new Permitted set */ if (!cap_issubset (*permitted, - cap_combine (current->cap_permitted, - current->cap_permitted))) { + cap_combine (cred->cap_permitted, + cred->cap_permitted))) { return -EPERM; } @@ -155,9 +160,11 @@ void cap_capset_set(const kernel_cap_t *effective, const kernel_cap_t *inheritable, const kernel_cap_t *permitted) { - current->cap_effective = *effective; - current->cap_inheritable = *inheritable; - current->cap_permitted = *permitted; + struct cred *cred = current->cred; + + cred->cap_effective = *effective; + cred->cap_inheritable = *inheritable; + cred->cap_permitted = *permitted; } static inline void bprm_clear_caps(struct linux_binprm *bprm) @@ -211,8 +218,8 @@ static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, * pP' = (X & fP) | (pI & fI) */ bprm->cap_post_exec_permitted.cap[i] = - (current->cap_bset.cap[i] & permitted) | - (current->cap_inheritable.cap[i] & inheritable); + (current->cred->cap_bset.cap[i] & permitted) | + (current->cred->cap_inheritable.cap[i] & inheritable); if (permitted & ~bprm->cap_post_exec_permitted.cap[i]) { /* @@ -354,8 +361,8 @@ int cap_bprm_set_security (struct linux_binprm *bprm) if (bprm->e_uid == 0 || current_uid() == 0) { /* pP' = (cap_bset & ~0) | (pI & ~0) */ bprm->cap_post_exec_permitted = cap_combine( - current->cap_bset, current->cap_inheritable - ); + current->cred->cap_bset, + current->cred->cap_inheritable); bprm->cap_effective = (bprm->e_uid == 0); ret = 0; } @@ -366,44 +373,39 @@ int cap_bprm_set_security (struct linux_binprm *bprm) void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) { - kernel_cap_t pP = current->cap_permitted; - kernel_cap_t pE = current->cap_effective; - uid_t uid; - gid_t gid; + struct cred *cred = current->cred; - current_uid_gid(&uid, &gid); - - if (bprm->e_uid != uid || bprm->e_gid != gid || + if (bprm->e_uid != cred->uid || bprm->e_gid != cred->gid || !cap_issubset(bprm->cap_post_exec_permitted, - current->cap_permitted)) { + cred->cap_permitted)) { set_dumpable(current->mm, suid_dumpable); current->pdeath_signal = 0; if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) { if (!capable(CAP_SETUID)) { - bprm->e_uid = uid; - bprm->e_gid = gid; + bprm->e_uid = cred->uid; + bprm->e_gid = cred->gid; } if (cap_limit_ptraced_target()) { bprm->cap_post_exec_permitted = cap_intersect( bprm->cap_post_exec_permitted, - current->cap_permitted); + cred->cap_permitted); } } } - current->suid = current->euid = current->fsuid = bprm->e_uid; - current->sgid = current->egid = current->fsgid = bprm->e_gid; + cred->suid = cred->euid = cred->fsuid = bprm->e_uid; + cred->sgid = cred->egid = cred->fsgid = bprm->e_gid; /* For init, we want to retain the capabilities set * in the init_task struct. Thus we skip the usual * capability rules */ if (!is_global_init(current)) { - current->cap_permitted = bprm->cap_post_exec_permitted; + cred->cap_permitted = bprm->cap_post_exec_permitted; if (bprm->cap_effective) - current->cap_effective = bprm->cap_post_exec_permitted; + cred->cap_effective = bprm->cap_post_exec_permitted; else - cap_clear(current->cap_effective); + cap_clear(cred->cap_effective); } /* @@ -418,27 +420,30 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) * Number 1 above might fail if you don't have a full bset, but I think * that is interesting information to audit. */ - if (!cap_isclear(current->cap_effective)) { - if (!cap_issubset(CAP_FULL_SET, current->cap_effective) || - (bprm->e_uid != 0) || (current->uid != 0) || + if (!cap_isclear(cred->cap_effective)) { + if (!cap_issubset(CAP_FULL_SET, cred->cap_effective) || + (bprm->e_uid != 0) || (cred->uid != 0) || issecure(SECURE_NOROOT)) - audit_log_bprm_fcaps(bprm, &pP, &pE); + audit_log_bprm_fcaps(bprm, &cred->cap_permitted, + &cred->cap_effective); } - current->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); + cred->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); } int cap_bprm_secureexec (struct linux_binprm *bprm) { - if (current_uid() != 0) { + const struct cred *cred = current->cred; + + if (cred->uid != 0) { if (bprm->cap_effective) return 1; if (!cap_isclear(bprm->cap_post_exec_permitted)) return 1; } - return (current_euid() != current_uid() || - current_egid() != current_gid()); + return (cred->euid != cred->uid || + cred->egid != cred->gid); } int cap_inode_setxattr(struct dentry *dentry, const char *name, @@ -501,25 +506,27 @@ int cap_inode_removexattr(struct dentry *dentry, const char *name) static inline void cap_emulate_setxuid (int old_ruid, int old_euid, int old_suid) { - uid_t euid = current_euid(); + struct cred *cred = current->cred; if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) && - (current_uid() != 0 && euid != 0 && current_suid() != 0) && + (cred->uid != 0 && cred->euid != 0 && cred->suid != 0) && !issecure(SECURE_KEEP_CAPS)) { - cap_clear (current->cap_permitted); - cap_clear (current->cap_effective); + cap_clear (cred->cap_permitted); + cap_clear (cred->cap_effective); } - if (old_euid == 0 && euid != 0) { - cap_clear (current->cap_effective); + if (old_euid == 0 && cred->euid != 0) { + cap_clear (cred->cap_effective); } - if (old_euid != 0 && euid == 0) { - current->cap_effective = current->cap_permitted; + if (old_euid != 0 && cred->euid == 0) { + cred->cap_effective = cred->cap_permitted; } } int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, int flags) { + struct cred *cred = current->cred; + switch (flags) { case LSM_SETID_RE: case LSM_SETID_ID: @@ -541,16 +548,16 @@ int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, */ if (!issecure (SECURE_NO_SETUID_FIXUP)) { - if (old_fsuid == 0 && current_fsuid() != 0) { - current->cap_effective = + if (old_fsuid == 0 && cred->fsuid != 0) { + cred->cap_effective = cap_drop_fs_set( - current->cap_effective); + cred->cap_effective); } - if (old_fsuid != 0 && current_fsuid() == 0) { - current->cap_effective = + if (old_fsuid != 0 && cred->fsuid == 0) { + cred->cap_effective = cap_raise_fs_set( - current->cap_effective, - current->cap_permitted); + cred->cap_effective, + cred->cap_permitted); } } break; @@ -575,7 +582,8 @@ int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, */ static int cap_safe_nice(struct task_struct *p) { - if (!cap_issubset(p->cap_permitted, current->cap_permitted) && + if (!cap_issubset(p->cred->cap_permitted, + current->cred->cap_permitted) && !capable(CAP_SYS_NICE)) return -EPERM; return 0; @@ -610,7 +618,7 @@ static long cap_prctl_drop(unsigned long cap) return -EPERM; if (!cap_valid(cap)) return -EINVAL; - cap_lower(current->cap_bset, cap); + cap_lower(current->cred->cap_bset, cap); return 0; } @@ -633,6 +641,7 @@ int cap_task_setnice (struct task_struct *p, int nice) int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5, long *rc_p) { + struct cred *cred = current->cred; long error = 0; switch (option) { @@ -640,7 +649,7 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, if (!cap_valid(arg2)) error = -EINVAL; else - error = !!cap_raised(current->cap_bset, arg2); + error = !!cap_raised(cred->cap_bset, arg2); break; #ifdef CONFIG_SECURITY_FILE_CAPABILITIES case PR_CAPBSET_DROP: @@ -667,9 +676,9 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, * capability-based-privilege environment. */ case PR_SET_SECUREBITS: - if ((((current->securebits & SECURE_ALL_LOCKS) >> 1) - & (current->securebits ^ arg2)) /*[1]*/ - || ((current->securebits & SECURE_ALL_LOCKS + if ((((cred->securebits & SECURE_ALL_LOCKS) >> 1) + & (cred->securebits ^ arg2)) /*[1]*/ + || ((cred->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0)) { /*[4]*/ @@ -682,11 +691,11 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, */ error = -EPERM; /* cannot change a locked bit */ } else { - current->securebits = arg2; + cred->securebits = arg2; } break; case PR_GET_SECUREBITS: - error = current->securebits; + error = cred->securebits; break; #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ @@ -701,10 +710,9 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, else if (issecure(SECURE_KEEP_CAPS_LOCKED)) error = -EPERM; else if (arg2) - current->securebits |= issecure_mask(SECURE_KEEP_CAPS); + cred->securebits |= issecure_mask(SECURE_KEEP_CAPS); else - current->securebits &= - ~issecure_mask(SECURE_KEEP_CAPS); + cred->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); break; default: @@ -719,11 +727,12 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, void cap_task_reparent_to_init (struct task_struct *p) { - cap_set_init_eff(p->cap_effective); - cap_clear(p->cap_inheritable); - cap_set_full(p->cap_permitted); - p->securebits = SECUREBITS_DEFAULT; - return; + struct cred *cred = p->cred; + + cap_set_init_eff(cred->cap_effective); + cap_clear(cred->cap_inheritable); + cap_set_full(cred->cap_permitted); + p->cred->securebits = SECUREBITS_DEFAULT; } int cap_syslog (int type) diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index fcce331eca72..8833b447adef 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -889,7 +889,7 @@ long keyctl_instantiate_key(key_serial_t id, /* the appropriate instantiation authorisation key must have been * assumed before calling this */ ret = -EPERM; - instkey = current->request_key_auth; + instkey = current->cred->request_key_auth; if (!instkey) goto error; @@ -932,8 +932,8 @@ long keyctl_instantiate_key(key_serial_t id, /* discard the assumed authority if it's just been disabled by * instantiation of the key */ if (ret == 0) { - key_put(current->request_key_auth); - current->request_key_auth = NULL; + key_put(current->cred->request_key_auth); + current->cred->request_key_auth = NULL; } error2: @@ -960,7 +960,7 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) /* the appropriate instantiation authorisation key must have been * assumed before calling this */ ret = -EPERM; - instkey = current->request_key_auth; + instkey = current->cred->request_key_auth; if (!instkey) goto error; @@ -983,8 +983,8 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) /* discard the assumed authority if it's just been disabled by * instantiation of the key */ if (ret == 0) { - key_put(current->request_key_auth); - current->request_key_auth = NULL; + key_put(current->cred->request_key_auth); + current->cred->request_key_auth = NULL; } error: @@ -999,6 +999,7 @@ error: */ long keyctl_set_reqkey_keyring(int reqkey_defl) { + struct cred *cred = current->cred; int ret; switch (reqkey_defl) { @@ -1018,10 +1019,10 @@ long keyctl_set_reqkey_keyring(int reqkey_defl) case KEY_REQKEY_DEFL_USER_KEYRING: case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: set: - current->jit_keyring = reqkey_defl; + cred->jit_keyring = reqkey_defl; case KEY_REQKEY_DEFL_NO_CHANGE: - return current->jit_keyring; + return cred->jit_keyring; case KEY_REQKEY_DEFL_GROUP_KEYRING: default: @@ -1086,8 +1087,8 @@ long keyctl_assume_authority(key_serial_t id) /* we divest ourselves of authority if given an ID of 0 */ if (id == 0) { - key_put(current->request_key_auth); - current->request_key_auth = NULL; + key_put(current->cred->request_key_auth); + current->cred->request_key_auth = NULL; ret = 0; goto error; } @@ -1103,8 +1104,8 @@ long keyctl_assume_authority(key_serial_t id) goto error; } - key_put(current->request_key_auth); - current->request_key_auth = authkey; + key_put(current->cred->request_key_auth); + current->cred->request_key_auth = authkey; ret = authkey->serial; error: diff --git a/security/keys/permission.c b/security/keys/permission.c index 3b41f9b52537..baf3d5f31e71 100644 --- a/security/keys/permission.c +++ b/security/keys/permission.c @@ -22,6 +22,7 @@ int key_task_permission(const key_ref_t key_ref, struct task_struct *context, key_perm_t perm) { + struct cred *cred = context->cred; struct key *key; key_perm_t kperm; int ret; @@ -29,7 +30,7 @@ int key_task_permission(const key_ref_t key_ref, key = key_ref_to_ptr(key_ref); /* use the second 8-bits of permissions for keys the caller owns */ - if (key->uid == context->fsuid) { + if (key->uid == cred->fsuid) { kperm = key->perm >> 16; goto use_these_perms; } @@ -37,14 +38,14 @@ int key_task_permission(const key_ref_t key_ref, /* use the third 8-bits of permissions for keys the caller has a group * membership in common with */ if (key->gid != -1 && key->perm & KEY_GRP_ALL) { - if (key->gid == context->fsgid) { + if (key->gid == cred->fsgid) { kperm = key->perm >> 8; goto use_these_perms; } - task_lock(context); - ret = groups_search(context->group_info, key->gid); - task_unlock(context); + spin_lock(&cred->lock); + ret = groups_search(cred->group_info, key->gid); + spin_unlock(&cred->lock); if (ret) { kperm = key->perm >> 8; diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 1c793b7090a7..b0904cdda2e7 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -42,7 +42,7 @@ struct key_user root_key_user = { */ int install_user_keyrings(void) { - struct user_struct *user = current->user; + struct user_struct *user = current->cred->user; struct key *uid_keyring, *session_keyring; char buf[20]; int ret; @@ -156,7 +156,7 @@ int install_thread_keyring(void) sprintf(buf, "_tid.%u", tsk->pid); - keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, + keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk, KEY_ALLOC_QUOTA_OVERRUN, NULL); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); @@ -164,8 +164,8 @@ int install_thread_keyring(void) } task_lock(tsk); - old = tsk->thread_keyring; - tsk->thread_keyring = keyring; + old = tsk->cred->thread_keyring; + tsk->cred->thread_keyring = keyring; task_unlock(tsk); ret = 0; @@ -192,7 +192,7 @@ int install_process_keyring(void) if (!tsk->signal->process_keyring) { sprintf(buf, "_pid.%u", tsk->tgid); - keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, + keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk, KEY_ALLOC_QUOTA_OVERRUN, NULL); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); @@ -238,7 +238,7 @@ static int install_session_keyring(struct key *keyring) if (tsk->signal->session_keyring) flags = KEY_ALLOC_IN_QUOTA; - keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, + keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk, flags, NULL); if (IS_ERR(keyring)) return PTR_ERR(keyring); @@ -292,14 +292,14 @@ int copy_thread_group_keys(struct task_struct *tsk) */ int copy_keys(unsigned long clone_flags, struct task_struct *tsk) { - key_check(tsk->thread_keyring); - key_check(tsk->request_key_auth); + key_check(tsk->cred->thread_keyring); + key_check(tsk->cred->request_key_auth); /* no thread keyring yet */ - tsk->thread_keyring = NULL; + tsk->cred->thread_keyring = NULL; /* copy the request_key() authorisation for this thread */ - key_get(tsk->request_key_auth); + key_get(tsk->cred->request_key_auth); return 0; @@ -322,8 +322,8 @@ void exit_thread_group_keys(struct signal_struct *tg) */ void exit_keys(struct task_struct *tsk) { - key_put(tsk->thread_keyring); - key_put(tsk->request_key_auth); + key_put(tsk->cred->thread_keyring); + key_put(tsk->cred->request_key_auth); } /* end exit_keys() */ @@ -337,8 +337,8 @@ int exec_keys(struct task_struct *tsk) /* newly exec'd tasks don't get a thread keyring */ task_lock(tsk); - old = tsk->thread_keyring; - tsk->thread_keyring = NULL; + old = tsk->cred->thread_keyring; + tsk->cred->thread_keyring = NULL; task_unlock(tsk); key_put(old); @@ -373,10 +373,11 @@ int suid_keys(struct task_struct *tsk) void key_fsuid_changed(struct task_struct *tsk) { /* update the ownership of the thread keyring */ - if (tsk->thread_keyring) { - down_write(&tsk->thread_keyring->sem); - tsk->thread_keyring->uid = tsk->fsuid; - up_write(&tsk->thread_keyring->sem); + BUG_ON(!tsk->cred); + if (tsk->cred->thread_keyring) { + down_write(&tsk->cred->thread_keyring->sem); + tsk->cred->thread_keyring->uid = tsk->cred->fsuid; + up_write(&tsk->cred->thread_keyring->sem); } } /* end key_fsuid_changed() */ @@ -388,10 +389,11 @@ void key_fsuid_changed(struct task_struct *tsk) void key_fsgid_changed(struct task_struct *tsk) { /* update the ownership of the thread keyring */ - if (tsk->thread_keyring) { - down_write(&tsk->thread_keyring->sem); - tsk->thread_keyring->gid = tsk->fsgid; - up_write(&tsk->thread_keyring->sem); + BUG_ON(!tsk->cred); + if (tsk->cred->thread_keyring) { + down_write(&tsk->cred->thread_keyring->sem); + tsk->cred->thread_keyring->gid = tsk->cred->fsgid; + up_write(&tsk->cred->thread_keyring->sem); } } /* end key_fsgid_changed() */ @@ -426,9 +428,9 @@ key_ref_t search_process_keyrings(struct key_type *type, err = ERR_PTR(-EAGAIN); /* search the thread keyring first */ - if (context->thread_keyring) { + if (context->cred->thread_keyring) { key_ref = keyring_search_aux( - make_key_ref(context->thread_keyring, 1), + make_key_ref(context->cred->thread_keyring, 1), context, type, description, match); if (!IS_ERR(key_ref)) goto found; @@ -493,9 +495,9 @@ key_ref_t search_process_keyrings(struct key_type *type, } } /* or search the user-session keyring */ - else if (context->user->session_keyring) { + else if (context->cred->user->session_keyring) { key_ref = keyring_search_aux( - make_key_ref(context->user->session_keyring, 1), + make_key_ref(context->cred->user->session_keyring, 1), context, type, description, match); if (!IS_ERR(key_ref)) goto found; @@ -517,20 +519,20 @@ key_ref_t search_process_keyrings(struct key_type *type, * search the keyrings of the process mentioned there * - we don't permit access to request_key auth keys via this method */ - if (context->request_key_auth && + if (context->cred->request_key_auth && context == current && type != &key_type_request_key_auth ) { /* defend against the auth key being revoked */ - down_read(&context->request_key_auth->sem); + down_read(&context->cred->request_key_auth->sem); - if (key_validate(context->request_key_auth) == 0) { - rka = context->request_key_auth->payload.data; + if (key_validate(context->cred->request_key_auth) == 0) { + rka = context->cred->request_key_auth->payload.data; key_ref = search_process_keyrings(type, description, match, rka->context); - up_read(&context->request_key_auth->sem); + up_read(&context->cred->request_key_auth->sem); if (!IS_ERR(key_ref)) goto found; @@ -547,7 +549,7 @@ key_ref_t search_process_keyrings(struct key_type *type, break; } } else { - up_read(&context->request_key_auth->sem); + up_read(&context->cred->request_key_auth->sem); } } @@ -580,15 +582,16 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, { struct request_key_auth *rka; struct task_struct *t = current; - key_ref_t key_ref, skey_ref; + struct cred *cred = t->cred; struct key *key; + key_ref_t key_ref, skey_ref; int ret; key_ref = ERR_PTR(-ENOKEY); switch (id) { case KEY_SPEC_THREAD_KEYRING: - if (!t->thread_keyring) { + if (!cred->thread_keyring) { if (!create) goto error; @@ -599,7 +602,7 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, } } - key = t->thread_keyring; + key = cred->thread_keyring; atomic_inc(&key->usage); key_ref = make_key_ref(key, 1); break; @@ -628,7 +631,8 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, ret = install_user_keyrings(); if (ret < 0) goto error; - ret = install_session_keyring(t->user->session_keyring); + ret = install_session_keyring( + cred->user->session_keyring); if (ret < 0) goto error; } @@ -641,25 +645,25 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, break; case KEY_SPEC_USER_KEYRING: - if (!t->user->uid_keyring) { + if (!cred->user->uid_keyring) { ret = install_user_keyrings(); if (ret < 0) goto error; } - key = t->user->uid_keyring; + key = cred->user->uid_keyring; atomic_inc(&key->usage); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_USER_SESSION_KEYRING: - if (!t->user->session_keyring) { + if (!cred->user->session_keyring) { ret = install_user_keyrings(); if (ret < 0) goto error; } - key = t->user->session_keyring; + key = cred->user->session_keyring; atomic_inc(&key->usage); key_ref = make_key_ref(key, 1); break; @@ -670,7 +674,7 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, goto error; case KEY_SPEC_REQKEY_AUTH_KEY: - key = t->request_key_auth; + key = cred->request_key_auth; if (!key) goto error; @@ -679,19 +683,19 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, break; case KEY_SPEC_REQUESTOR_KEYRING: - if (!t->request_key_auth) + if (!cred->request_key_auth) goto error; - down_read(&t->request_key_auth->sem); - if (t->request_key_auth->flags & KEY_FLAG_REVOKED) { + down_read(&cred->request_key_auth->sem); + if (cred->request_key_auth->flags & KEY_FLAG_REVOKED) { key_ref = ERR_PTR(-EKEYREVOKED); key = NULL; } else { - rka = t->request_key_auth->payload.data; + rka = cred->request_key_auth->payload.data; key = rka->dest_keyring; atomic_inc(&key->usage); } - up_read(&t->request_key_auth->sem); + up_read(&cred->request_key_auth->sem); if (!key) goto error; key_ref = make_key_ref(key, 1); @@ -791,7 +795,7 @@ long join_session_keyring(const char *name) keyring = find_keyring_by_name(name, false); if (PTR_ERR(keyring) == -ENOKEY) { /* not found - try and create a new one */ - keyring = keyring_alloc(name, tsk->uid, tsk->gid, tsk, + keyring = keyring_alloc(name, tsk->cred->uid, tsk->cred->gid, tsk, KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 8e9d93b4a402..3e9b9eb1dd28 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -104,7 +104,8 @@ static int call_sbin_request_key(struct key_construction *cons, /* we specify the process's default keyrings */ sprintf(keyring_str[0], "%d", - tsk->thread_keyring ? tsk->thread_keyring->serial : 0); + tsk->cred->thread_keyring ? + tsk->cred->thread_keyring->serial : 0); prkey = 0; if (tsk->signal->process_keyring) @@ -117,7 +118,7 @@ static int call_sbin_request_key(struct key_construction *cons, sskey = rcu_dereference(tsk->signal->session_keyring)->serial; rcu_read_unlock(); } else { - sskey = tsk->user->session_keyring->serial; + sskey = tsk->cred->user->session_keyring->serial; } sprintf(keyring_str[2], "%d", sskey); @@ -232,11 +233,11 @@ static void construct_get_dest_keyring(struct key **_dest_keyring) } else { /* use a default keyring; falling through the cases until we * find one that we actually have */ - switch (tsk->jit_keyring) { + switch (tsk->cred->jit_keyring) { case KEY_REQKEY_DEFL_DEFAULT: case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: - if (tsk->request_key_auth) { - authkey = tsk->request_key_auth; + if (tsk->cred->request_key_auth) { + authkey = tsk->cred->request_key_auth; down_read(&authkey->sem); rka = authkey->payload.data; if (!test_bit(KEY_FLAG_REVOKED, @@ -249,7 +250,7 @@ static void construct_get_dest_keyring(struct key **_dest_keyring) } case KEY_REQKEY_DEFL_THREAD_KEYRING: - dest_keyring = key_get(tsk->thread_keyring); + dest_keyring = key_get(tsk->cred->thread_keyring); if (dest_keyring) break; @@ -268,11 +269,12 @@ static void construct_get_dest_keyring(struct key **_dest_keyring) break; case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: - dest_keyring = key_get(tsk->user->session_keyring); + dest_keyring = + key_get(tsk->cred->user->session_keyring); break; case KEY_REQKEY_DEFL_USER_KEYRING: - dest_keyring = key_get(tsk->user->uid_keyring); + dest_keyring = key_get(tsk->cred->user->uid_keyring); break; case KEY_REQKEY_DEFL_GROUP_KEYRING: diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c index 1762d44711d5..2125579d5d73 100644 --- a/security/keys/request_key_auth.c +++ b/security/keys/request_key_auth.c @@ -164,22 +164,22 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, /* see if the calling process is already servicing the key request of * another process */ - if (current->request_key_auth) { + if (current->cred->request_key_auth) { /* it is - use that instantiation context here too */ - down_read(¤t->request_key_auth->sem); + down_read(¤t->cred->request_key_auth->sem); /* if the auth key has been revoked, then the key we're * servicing is already instantiated */ if (test_bit(KEY_FLAG_REVOKED, - ¤t->request_key_auth->flags)) + ¤t->cred->request_key_auth->flags)) goto auth_key_revoked; - irka = current->request_key_auth->payload.data; + irka = current->cred->request_key_auth->payload.data; rka->context = irka->context; rka->pid = irka->pid; get_task_struct(rka->context); - up_read(¤t->request_key_auth->sem); + up_read(¤t->cred->request_key_auth->sem); } else { /* it isn't - use this process as the context */ @@ -214,7 +214,7 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, return authkey; auth_key_revoked: - up_read(¤t->request_key_auth->sem); + up_read(¤t->cred->request_key_auth->sem); kfree(rka->callout_info); kfree(rka); kleave("= -EKEYREVOKED"); diff --git a/security/selinux/exports.c b/security/selinux/exports.c index 64af2d3409ef..cf02490cd1eb 100644 --- a/security/selinux/exports.c +++ b/security/selinux/exports.c @@ -39,7 +39,7 @@ EXPORT_SYMBOL_GPL(selinux_string_to_sid); int selinux_secmark_relabel_packet_permission(u32 sid) { if (selinux_enabled) { - struct task_security_struct *tsec = current->security; + struct task_security_struct *tsec = current->cred->security; return avc_has_perm(tsec->sid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 9f6da154cc82..328308f2882a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -167,21 +167,21 @@ static int task_alloc_security(struct task_struct *task) return -ENOMEM; tsec->osid = tsec->sid = SECINITSID_UNLABELED; - task->security = tsec; + task->cred->security = tsec; return 0; } static void task_free_security(struct task_struct *task) { - struct task_security_struct *tsec = task->security; - task->security = NULL; + struct task_security_struct *tsec = task->cred->security; + task->cred->security = NULL; kfree(tsec); } static int inode_alloc_security(struct inode *inode) { - struct task_security_struct *tsec = current->security; + struct task_security_struct *tsec = current->cred->security; struct inode_security_struct *isec; isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); @@ -215,7 +215,7 @@ static void inode_free_security(struct inode *inode) static int file_alloc_security(struct file *file) { - struct task_security_struct *tsec = current->security; + struct task_security_struct *tsec = current->cred->security; struct file_security_struct *fsec; fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL); @@ -554,7 +554,7 @@ static int selinux_set_mnt_opts(struct super_block *sb, struct security_mnt_opts *opts) { int rc = 0, i; - struct task_security_struct *tsec = current->security; + struct task_security_struct *tsec = current->cred->security; struct superblock_security_struct *sbsec = sb->s_security; const char *name = sb->s_type->name; struct inode *inode = sbsec->sb->s_root->d_inode; @@ -1353,8 +1353,8 @@ static int task_has_perm(struct task_struct *tsk1, { struct task_security_struct *tsec1, *tsec2; - tsec1 = tsk1->security; - tsec2 = tsk2->security; + tsec1 = tsk1->cred->security; + tsec2 = tsk2->cred->security; return avc_has_perm(tsec1->sid, tsec2->sid, SECCLASS_PROCESS, perms, NULL); } @@ -1374,7 +1374,7 @@ static int task_has_capability(struct task_struct *tsk, u32 av = CAP_TO_MASK(cap); int rc; - tsec = tsk->security; + tsec = tsk->cred->security; AVC_AUDIT_DATA_INIT(&ad, CAP); ad.tsk = tsk; @@ -1405,7 +1405,7 @@ static int task_has_system(struct task_struct *tsk, { struct task_security_struct *tsec; - tsec = tsk->security; + tsec = tsk->cred->security; return avc_has_perm(tsec->sid, SECINITSID_KERNEL, SECCLASS_SYSTEM, perms, NULL); @@ -1426,7 +1426,7 @@ static int inode_has_perm(struct task_struct *tsk, if (unlikely(IS_PRIVATE(inode))) return 0; - tsec = tsk->security; + tsec = tsk->cred->security; isec = inode->i_security; if (!adp) { @@ -1466,7 +1466,7 @@ static int file_has_perm(struct task_struct *tsk, struct file *file, u32 av) { - struct task_security_struct *tsec = tsk->security; + struct task_security_struct *tsec = tsk->cred->security; struct file_security_struct *fsec = file->f_security; struct inode *inode = file->f_path.dentry->d_inode; struct avc_audit_data ad; @@ -1503,7 +1503,7 @@ static int may_create(struct inode *dir, struct avc_audit_data ad; int rc; - tsec = current->security; + tsec = current->cred->security; dsec = dir->i_security; sbsec = dir->i_sb->s_security; @@ -1540,7 +1540,7 @@ static int may_create_key(u32 ksid, { struct task_security_struct *tsec; - tsec = ctx->security; + tsec = ctx->cred->security; return avc_has_perm(tsec->sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL); } @@ -1561,7 +1561,7 @@ static int may_link(struct inode *dir, u32 av; int rc; - tsec = current->security; + tsec = current->cred->security; dsec = dir->i_security; isec = dentry->d_inode->i_security; @@ -1606,7 +1606,7 @@ static inline int may_rename(struct inode *old_dir, int old_is_dir, new_is_dir; int rc; - tsec = current->security; + tsec = current->cred->security; old_dsec = old_dir->i_security; old_isec = old_dentry->d_inode->i_security; old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); @@ -1659,7 +1659,7 @@ static int superblock_has_perm(struct task_struct *tsk, struct task_security_struct *tsec; struct superblock_security_struct *sbsec; - tsec = tsk->security; + tsec = tsk->cred->security; sbsec = sb->s_security; return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); @@ -1758,8 +1758,8 @@ static int selinux_ptrace_may_access(struct task_struct *child, return rc; if (mode == PTRACE_MODE_READ) { - struct task_security_struct *tsec = current->security; - struct task_security_struct *csec = child->security; + struct task_security_struct *tsec = current->cred->security; + struct task_security_struct *csec = child->cred->security; return avc_has_perm(tsec->sid, csec->sid, SECCLASS_FILE, FILE__READ, NULL); } @@ -1874,7 +1874,7 @@ static int selinux_sysctl(ctl_table *table, int op) if (rc) return rc; - tsec = current->security; + tsec = current->cred->security; rc = selinux_sysctl_get_sid(table, (op == 0001) ? SECCLASS_DIR : SECCLASS_FILE, &tsid); @@ -2025,7 +2025,7 @@ static int selinux_bprm_set_security(struct linux_binprm *bprm) if (bsec->set) return 0; - tsec = current->security; + tsec = current->cred->security; isec = inode->i_security; /* Default to the current task SID. */ @@ -2090,7 +2090,7 @@ static int selinux_bprm_check_security(struct linux_binprm *bprm) static int selinux_bprm_secureexec(struct linux_binprm *bprm) { - struct task_security_struct *tsec = current->security; + struct task_security_struct *tsec = current->cred->security; int atsecure = 0; if (tsec->osid != tsec->sid) { @@ -2214,7 +2214,7 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) secondary_ops->bprm_apply_creds(bprm, unsafe); - tsec = current->security; + tsec = current->cred->security; bsec = bprm->security; sid = bsec->sid; @@ -2243,7 +2243,7 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) rcu_read_lock(); tracer = tracehook_tracer_task(current); if (likely(tracer != NULL)) { - sec = tracer->security; + sec = tracer->cred->security; ptsid = sec->sid; } rcu_read_unlock(); @@ -2274,7 +2274,7 @@ static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) int rc, i; unsigned long flags; - tsec = current->security; + tsec = current->cred->security; bsec = bprm->security; if (bsec->unsafe) { @@ -2521,7 +2521,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir, int rc; char *namep = NULL, *context; - tsec = current->security; + tsec = current->cred->security; dsec = dir->i_security; sbsec = dir->i_sb->s_security; @@ -2706,7 +2706,7 @@ static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name) static int selinux_inode_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { - struct task_security_struct *tsec = current->security; + struct task_security_struct *tsec = current->cred->security; struct inode *inode = dentry->d_inode; struct inode_security_struct *isec = inode->i_security; struct superblock_security_struct *sbsec; @@ -2918,7 +2918,7 @@ static int selinux_revalidate_file_permission(struct file *file, int mask) static int selinux_file_permission(struct file *file, int mask) { struct inode *inode = file->f_path.dentry->d_inode; - struct task_security_struct *tsec = current->security; + struct task_security_struct *tsec = current->cred->security; struct file_security_struct *fsec = file->f_security; struct inode_security_struct *isec = inode->i_security; @@ -2995,7 +2995,8 @@ static int selinux_file_mmap(struct file *file, unsigned long reqprot, unsigned long addr, unsigned long addr_only) { int rc = 0; - u32 sid = ((struct task_security_struct *)(current->security))->sid; + u32 sid = ((struct task_security_struct *) + (current->cred->security))->sid; if (addr < mmap_min_addr) rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, @@ -3107,7 +3108,7 @@ static int selinux_file_set_fowner(struct file *file) struct task_security_struct *tsec; struct file_security_struct *fsec; - tsec = current->security; + tsec = current->cred->security; fsec = file->f_security; fsec->fown_sid = tsec->sid; @@ -3125,7 +3126,7 @@ static int selinux_file_send_sigiotask(struct task_struct *tsk, /* struct fown_struct is never outside the context of a struct file */ file = container_of(fown, struct file, f_owner); - tsec = tsk->security; + tsec = tsk->cred->security; fsec = file->f_security; if (!signum) @@ -3188,12 +3189,12 @@ static int selinux_task_alloc_security(struct task_struct *tsk) struct task_security_struct *tsec1, *tsec2; int rc; - tsec1 = current->security; + tsec1 = current->cred->security; rc = task_alloc_security(tsk); if (rc) return rc; - tsec2 = tsk->security; + tsec2 = tsk->cred->security; tsec2->osid = tsec1->osid; tsec2->sid = tsec1->sid; @@ -3251,7 +3252,7 @@ static int selinux_task_getsid(struct task_struct *p) static void selinux_task_getsecid(struct task_struct *p, u32 *secid) { - struct task_security_struct *tsec = p->security; + struct task_security_struct *tsec = p->cred->security; *secid = tsec->sid; } @@ -3343,7 +3344,7 @@ static int selinux_task_kill(struct task_struct *p, struct siginfo *info, perm = PROCESS__SIGNULL; /* null signal; existence test */ else perm = signal_to_av(sig); - tsec = p->security; + tsec = p->cred->security; if (secid) rc = avc_has_perm(secid, tsec->sid, SECCLASS_PROCESS, perm, NULL); else @@ -3375,7 +3376,7 @@ static void selinux_task_reparent_to_init(struct task_struct *p) secondary_ops->task_reparent_to_init(p); - tsec = p->security; + tsec = p->cred->security; tsec->osid = tsec->sid; tsec->sid = SECINITSID_KERNEL; return; @@ -3384,7 +3385,7 @@ static void selinux_task_reparent_to_init(struct task_struct *p) static void selinux_task_to_inode(struct task_struct *p, struct inode *inode) { - struct task_security_struct *tsec = p->security; + struct task_security_struct *tsec = p->cred->security; struct inode_security_struct *isec = inode->i_security; isec->sid = tsec->sid; @@ -3632,7 +3633,7 @@ static int socket_has_perm(struct task_struct *task, struct socket *sock, struct avc_audit_data ad; int err = 0; - tsec = task->security; + tsec = task->cred->security; isec = SOCK_INODE(sock)->i_security; if (isec->sid == SECINITSID_KERNEL) @@ -3656,7 +3657,7 @@ static int selinux_socket_create(int family, int type, if (kern) goto out; - tsec = current->security; + tsec = current->cred->security; newsid = tsec->sockcreate_sid ? : tsec->sid; err = avc_has_perm(tsec->sid, newsid, socket_type_to_security_class(family, type, @@ -3677,7 +3678,7 @@ static int selinux_socket_post_create(struct socket *sock, int family, isec = SOCK_INODE(sock)->i_security; - tsec = current->security; + tsec = current->cred->security; newsid = tsec->sockcreate_sid ? : tsec->sid; isec->sclass = socket_type_to_security_class(family, type, protocol); isec->sid = kern ? SECINITSID_KERNEL : newsid; @@ -3723,7 +3724,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in struct sock *sk = sock->sk; u32 sid, node_perm; - tsec = current->security; + tsec = current->cred->security; isec = SOCK_INODE(sock)->i_security; if (family == PF_INET) { @@ -4764,7 +4765,7 @@ static int ipc_alloc_security(struct task_struct *task, struct kern_ipc_perm *perm, u16 sclass) { - struct task_security_struct *tsec = task->security; + struct task_security_struct *tsec = task->cred->security; struct ipc_security_struct *isec; isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL); @@ -4814,7 +4815,7 @@ static int ipc_has_perm(struct kern_ipc_perm *ipc_perms, struct ipc_security_struct *isec; struct avc_audit_data ad; - tsec = current->security; + tsec = current->cred->security; isec = ipc_perms->security; AVC_AUDIT_DATA_INIT(&ad, IPC); @@ -4845,7 +4846,7 @@ static int selinux_msg_queue_alloc_security(struct msg_queue *msq) if (rc) return rc; - tsec = current->security; + tsec = current->cred->security; isec = msq->q_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); @@ -4871,7 +4872,7 @@ static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg) struct ipc_security_struct *isec; struct avc_audit_data ad; - tsec = current->security; + tsec = current->cred->security; isec = msq->q_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); @@ -4917,7 +4918,7 @@ static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, struct avc_audit_data ad; int rc; - tsec = current->security; + tsec = current->cred->security; isec = msq->q_perm.security; msec = msg->security; @@ -4965,7 +4966,7 @@ static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, struct avc_audit_data ad; int rc; - tsec = target->security; + tsec = target->cred->security; isec = msq->q_perm.security; msec = msg->security; @@ -4992,7 +4993,7 @@ static int selinux_shm_alloc_security(struct shmid_kernel *shp) if (rc) return rc; - tsec = current->security; + tsec = current->cred->security; isec = shp->shm_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); @@ -5018,7 +5019,7 @@ static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg) struct ipc_security_struct *isec; struct avc_audit_data ad; - tsec = current->security; + tsec = current->cred->security; isec = shp->shm_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); @@ -5091,7 +5092,7 @@ static int selinux_sem_alloc_security(struct sem_array *sma) if (rc) return rc; - tsec = current->security; + tsec = current->cred->security; isec = sma->sem_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); @@ -5117,7 +5118,7 @@ static int selinux_sem_associate(struct sem_array *sma, int semflg) struct ipc_security_struct *isec; struct avc_audit_data ad; - tsec = current->security; + tsec = current->cred->security; isec = sma->sem_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); @@ -5224,7 +5225,7 @@ static int selinux_getprocattr(struct task_struct *p, return error; } - tsec = p->security; + tsec = p->cred->security; if (!strcmp(name, "current")) sid = tsec->sid; @@ -5308,7 +5309,7 @@ static int selinux_setprocattr(struct task_struct *p, operation. See selinux_bprm_set_security for the execve checks and may_create for the file creation checks. The operation will then fail if the context is not permitted. */ - tsec = p->security; + tsec = p->cred->security; if (!strcmp(name, "exec")) tsec->exec_sid = sid; else if (!strcmp(name, "fscreate")) @@ -5361,7 +5362,8 @@ boundary_ok: rcu_read_lock(); tracer = tracehook_tracer_task(p); if (tracer != NULL) { - struct task_security_struct *ptsec = tracer->security; + struct task_security_struct *ptsec = + tracer->cred->security; u32 ptsid = ptsec->sid; rcu_read_unlock(); error = avc_has_perm_noaudit(ptsid, sid, @@ -5405,7 +5407,7 @@ static void selinux_release_secctx(char *secdata, u32 seclen) static int selinux_key_alloc(struct key *k, struct task_struct *tsk, unsigned long flags) { - struct task_security_struct *tsec = tsk->security; + struct task_security_struct *tsec = tsk->cred->security; struct key_security_struct *ksec; ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); @@ -5439,7 +5441,7 @@ static int selinux_key_permission(key_ref_t key_ref, key = key_ref_to_ptr(key_ref); - tsec = ctx->security; + tsec = ctx->cred->security; ksec = key->security; /* if no specific permissions are requested, we skip the @@ -5683,7 +5685,7 @@ static __init int selinux_init(void) /* Set the security state for the initial task. */ if (task_alloc_security(current)) panic("SELinux: Failed to initialize initial task.\n"); - tsec = current->security; + tsec = current->cred->security; tsec->osid = tsec->sid = SECINITSID_KERNEL; sel_inode_cache = kmem_cache_create("selinux_inode_security", diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 69c9dccc8cf0..10715d1330b9 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -97,7 +97,7 @@ static int task_has_security(struct task_struct *tsk, { struct task_security_struct *tsec; - tsec = tsk->security; + tsec = tsk->cred->security; if (!tsec) return -EACCES; diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c index 8f17f542a116..d7db76617b0e 100644 --- a/security/selinux/xfrm.c +++ b/security/selinux/xfrm.c @@ -197,7 +197,7 @@ static int selinux_xfrm_sec_ctx_alloc(struct xfrm_sec_ctx **ctxp, struct xfrm_user_sec_ctx *uctx, u32 sid) { int rc = 0; - struct task_security_struct *tsec = current->security; + struct task_security_struct *tsec = current->cred->security; struct xfrm_sec_ctx *ctx = NULL; char *ctx_str = NULL; u32 str_len; @@ -333,7 +333,7 @@ void selinux_xfrm_policy_free(struct xfrm_sec_ctx *ctx) */ int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx) { - struct task_security_struct *tsec = current->security; + struct task_security_struct *tsec = current->cred->security; int rc = 0; if (ctx) { @@ -378,7 +378,7 @@ void selinux_xfrm_state_free(struct xfrm_state *x) */ int selinux_xfrm_state_delete(struct xfrm_state *x) { - struct task_security_struct *tsec = current->security; + struct task_security_struct *tsec = current->cred->security; struct xfrm_sec_ctx *ctx = x->security; int rc = 0; diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index 79ff21ed4c3b..b6dd4fc0fb0b 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -164,7 +164,7 @@ int smk_curacc(char *obj_label, u32 mode) { int rc; - rc = smk_access(current->security, obj_label, mode); + rc = smk_access(current->cred->security, obj_label, mode); if (rc == 0) return 0; @@ -173,7 +173,7 @@ int smk_curacc(char *obj_label, u32 mode) * only one that gets privilege and current does not * have that label. */ - if (smack_onlycap != NULL && smack_onlycap != current->security) + if (smack_onlycap != NULL && smack_onlycap != current->cred->security) return rc; if (capable(CAP_MAC_OVERRIDE)) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 6e2dc0bab70d..791da238d049 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -102,7 +102,8 @@ static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode) if (rc != 0) return rc; - rc = smk_access(current->security, ctp->security, MAY_READWRITE); + rc = smk_access(current->cred->security, ctp->cred->security, + MAY_READWRITE); if (rc != 0 && capable(CAP_MAC_OVERRIDE)) return 0; return rc; @@ -124,7 +125,8 @@ static int smack_ptrace_traceme(struct task_struct *ptp) if (rc != 0) return rc; - rc = smk_access(ptp->security, current->security, MAY_READWRITE); + rc = smk_access(ptp->cred->security, current->cred->security, + MAY_READWRITE); if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE)) return 0; return rc; @@ -141,7 +143,7 @@ static int smack_ptrace_traceme(struct task_struct *ptp) static int smack_syslog(int type) { int rc; - char *sp = current->security; + char *sp = current->cred->security; rc = cap_syslog(type); if (rc != 0) @@ -373,7 +375,7 @@ static int smack_sb_umount(struct vfsmount *mnt, int flags) */ static int smack_inode_alloc_security(struct inode *inode) { - inode->i_security = new_inode_smack(current->security); + inode->i_security = new_inode_smack(current->cred->security); if (inode->i_security == NULL) return -ENOMEM; return 0; @@ -818,7 +820,7 @@ static int smack_file_permission(struct file *file, int mask) */ static int smack_file_alloc_security(struct file *file) { - file->f_security = current->security; + file->f_security = current->cred->security; return 0; } @@ -916,7 +918,7 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd, */ static int smack_file_set_fowner(struct file *file) { - file->f_security = current->security; + file->f_security = current->cred->security; return 0; } @@ -941,7 +943,7 @@ static int smack_file_send_sigiotask(struct task_struct *tsk, * struct fown_struct is never outside the context of a struct file */ file = container_of(fown, struct file, f_owner); - rc = smk_access(file->f_security, tsk->security, MAY_WRITE); + rc = smk_access(file->f_security, tsk->cred->security, MAY_WRITE); if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE)) return 0; return rc; @@ -984,7 +986,7 @@ static int smack_file_receive(struct file *file) */ static int smack_task_alloc_security(struct task_struct *tsk) { - tsk->security = current->security; + tsk->cred->security = current->cred->security; return 0; } @@ -999,7 +1001,7 @@ static int smack_task_alloc_security(struct task_struct *tsk) */ static void smack_task_free_security(struct task_struct *task) { - task->security = NULL; + task->cred->security = NULL; } /** @@ -1011,7 +1013,7 @@ static void smack_task_free_security(struct task_struct *task) */ static int smack_task_setpgid(struct task_struct *p, pid_t pgid) { - return smk_curacc(p->security, MAY_WRITE); + return smk_curacc(p->cred->security, MAY_WRITE); } /** @@ -1022,7 +1024,7 @@ static int smack_task_setpgid(struct task_struct *p, pid_t pgid) */ static int smack_task_getpgid(struct task_struct *p) { - return smk_curacc(p->security, MAY_READ); + return smk_curacc(p->cred->security, MAY_READ); } /** @@ -1033,7 +1035,7 @@ static int smack_task_getpgid(struct task_struct *p) */ static int smack_task_getsid(struct task_struct *p) { - return smk_curacc(p->security, MAY_READ); + return smk_curacc(p->cred->security, MAY_READ); } /** @@ -1045,7 +1047,7 @@ static int smack_task_getsid(struct task_struct *p) */ static void smack_task_getsecid(struct task_struct *p, u32 *secid) { - *secid = smack_to_secid(p->security); + *secid = smack_to_secid(p->cred->security); } /** @@ -1061,7 +1063,7 @@ static int smack_task_setnice(struct task_struct *p, int nice) rc = cap_task_setnice(p, nice); if (rc == 0) - rc = smk_curacc(p->security, MAY_WRITE); + rc = smk_curacc(p->cred->security, MAY_WRITE); return rc; } @@ -1078,7 +1080,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio) rc = cap_task_setioprio(p, ioprio); if (rc == 0) - rc = smk_curacc(p->security, MAY_WRITE); + rc = smk_curacc(p->cred->security, MAY_WRITE); return rc; } @@ -1090,7 +1092,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio) */ static int smack_task_getioprio(struct task_struct *p) { - return smk_curacc(p->security, MAY_READ); + return smk_curacc(p->cred->security, MAY_READ); } /** @@ -1108,7 +1110,7 @@ static int smack_task_setscheduler(struct task_struct *p, int policy, rc = cap_task_setscheduler(p, policy, lp); if (rc == 0) - rc = smk_curacc(p->security, MAY_WRITE); + rc = smk_curacc(p->cred->security, MAY_WRITE); return rc; } @@ -1120,7 +1122,7 @@ static int smack_task_setscheduler(struct task_struct *p, int policy, */ static int smack_task_getscheduler(struct task_struct *p) { - return smk_curacc(p->security, MAY_READ); + return smk_curacc(p->cred->security, MAY_READ); } /** @@ -1131,7 +1133,7 @@ static int smack_task_getscheduler(struct task_struct *p) */ static int smack_task_movememory(struct task_struct *p) { - return smk_curacc(p->security, MAY_WRITE); + return smk_curacc(p->cred->security, MAY_WRITE); } /** @@ -1154,13 +1156,13 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info, * can write the receiver. */ if (secid == 0) - return smk_curacc(p->security, MAY_WRITE); + return smk_curacc(p->cred->security, MAY_WRITE); /* * If the secid isn't 0 we're dealing with some USB IO * specific behavior. This is not clean. For one thing * we can't take privilege into account. */ - return smk_access(smack_from_secid(secid), p->security, MAY_WRITE); + return smk_access(smack_from_secid(secid), p->cred->security, MAY_WRITE); } /** @@ -1173,7 +1175,7 @@ static int smack_task_wait(struct task_struct *p) { int rc; - rc = smk_access(current->security, p->security, MAY_WRITE); + rc = smk_access(current->cred->security, p->cred->security, MAY_WRITE); if (rc == 0) return 0; @@ -1204,7 +1206,7 @@ static int smack_task_wait(struct task_struct *p) static void smack_task_to_inode(struct task_struct *p, struct inode *inode) { struct inode_smack *isp = inode->i_security; - isp->smk_inode = p->security; + isp->smk_inode = p->cred->security; } /* @@ -1223,7 +1225,7 @@ static void smack_task_to_inode(struct task_struct *p, struct inode *inode) */ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) { - char *csp = current->security; + char *csp = current->cred->security; struct socket_smack *ssp; ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); @@ -1448,7 +1450,7 @@ static int smack_flags_to_may(int flags) */ static int smack_msg_msg_alloc_security(struct msg_msg *msg) { - msg->security = current->security; + msg->security = current->cred->security; return 0; } @@ -1484,7 +1486,7 @@ static int smack_shm_alloc_security(struct shmid_kernel *shp) { struct kern_ipc_perm *isp = &shp->shm_perm; - isp->security = current->security; + isp->security = current->cred->security; return 0; } @@ -1593,7 +1595,7 @@ static int smack_sem_alloc_security(struct sem_array *sma) { struct kern_ipc_perm *isp = &sma->sem_perm; - isp->security = current->security; + isp->security = current->cred->security; return 0; } @@ -1697,7 +1699,7 @@ static int smack_msg_queue_alloc_security(struct msg_queue *msq) { struct kern_ipc_perm *kisp = &msq->q_perm; - kisp->security = current->security; + kisp->security = current->cred->security; return 0; } @@ -1852,7 +1854,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) struct super_block *sbp; struct superblock_smack *sbsp; struct inode_smack *isp; - char *csp = current->security; + char *csp = current->cred->security; char *fetched; char *final; struct dentry *dp; @@ -2009,7 +2011,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value) if (strcmp(name, "current") != 0) return -EINVAL; - cp = kstrdup(p->security, GFP_KERNEL); + cp = kstrdup(p->cred->security, GFP_KERNEL); if (cp == NULL) return -ENOMEM; @@ -2055,7 +2057,7 @@ static int smack_setprocattr(struct task_struct *p, char *name, if (newsmack == NULL) return -EINVAL; - p->security = newsmack; + p->cred->security = newsmack; return size; } @@ -2288,8 +2290,8 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent) return; ssp = sk->sk_security; - ssp->smk_in = current->security; - ssp->smk_out = current->security; + ssp->smk_in = current->cred->security; + ssp->smk_out = current->cred->security; ssp->smk_packet[0] = '\0'; rc = smack_netlabel(sk); @@ -2362,7 +2364,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, static int smack_key_alloc(struct key *key, struct task_struct *tsk, unsigned long flags) { - key->security = tsk->security; + key->security = tsk->cred->security; return 0; } @@ -2403,10 +2405,11 @@ static int smack_key_permission(key_ref_t key_ref, /* * This should not occur */ - if (context->security == NULL) + if (context->cred->security == NULL) return -EACCES; - return smk_access(context->security, keyp->security, MAY_READWRITE); + return smk_access(context->cred->security, keyp->security, + MAY_READWRITE); } #endif /* CONFIG_KEYS */ @@ -2726,7 +2729,7 @@ static __init int smack_init(void) /* * Set the security state for the initial task. */ - current->security = &smack_known_floor.smk_known; + current->cred->security = &smack_known_floor.smk_known; /* * Initialize locks diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index c21d8c8bf0c7..c5ca279e0506 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -336,7 +336,7 @@ static void smk_cipso_doi(void) audit_info.loginuid = audit_get_loginuid(current); audit_info.sessionid = audit_get_sessionid(current); - audit_info.secid = smack_to_secid(current->security); + audit_info.secid = smack_to_secid(current->cred->security); rc = netlbl_cfg_map_del(NULL, &audit_info); if (rc != 0) @@ -371,7 +371,7 @@ static void smk_unlbl_ambient(char *oldambient) audit_info.loginuid = audit_get_loginuid(current); audit_info.sessionid = audit_get_sessionid(current); - audit_info.secid = smack_to_secid(current->security); + audit_info.secid = smack_to_secid(current->cred->security); if (oldambient != NULL) { rc = netlbl_cfg_map_del(oldambient, &audit_info); @@ -843,7 +843,7 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { char in[SMK_LABELLEN]; - char *sp = current->security; + char *sp = current->cred->security; if (!capable(CAP_MAC_ADMIN)) return -EPERM; -- cgit v1.2.3 From f1752eec6145c97163dbce62d17cf5d928e28a27 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:17 +1100 Subject: CRED: Detach the credentials from task_struct Detach the credentials from task_struct, duplicating them in copy_process() and releasing them in __put_task_struct(). Signed-off-by: David Howells Acked-by: James Morris Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/cred.h | 29 ++++++++++++++ include/linux/init_task.h | 16 +------- include/linux/sched.h | 1 - include/linux/security.h | 26 ++++++------- kernel/Makefile | 2 +- kernel/cred.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++ kernel/fork.c | 24 +++--------- security/capability.c | 8 ++-- security/security.c | 8 ++-- security/selinux/hooks.c | 32 ++++++++-------- security/smack/smack_lsm.c | 20 +++++----- 11 files changed, 179 insertions(+), 83 deletions(-) create mode 100644 kernel/cred.c (limited to 'include') diff --git a/include/linux/cred.h b/include/linux/cred.h index 3e65587a72e5..a7a686074cb0 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -158,4 +158,33 @@ do { \ *(_gid) = current->cred->fsgid; \ } while(0) +extern void __put_cred(struct cred *); +extern int copy_creds(struct task_struct *, unsigned long); + +/** + * get_cred - Get a reference on a set of credentials + * @cred: The credentials to reference + * + * Get a reference on the specified set of credentials. The caller must + * release the reference. + */ +static inline struct cred *get_cred(struct cred *cred) +{ + atomic_inc(&cred->usage); + return cred; +} + +/** + * put_cred - Release a reference to a set of credentials + * @cred: The credentials to release + * + * Release a reference to a set of credentials, deleting them when the last ref + * is released. + */ +static inline void put_cred(struct cred *cred) +{ + if (atomic_dec_and_test(&(cred)->usage)) + __put_cred(cred); +} + #endif /* _LINUX_CRED_H */ diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 9de41ccd67b5..5e24c54b6dfd 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -115,19 +115,6 @@ extern struct group_info init_groups; extern struct cred init_cred; -#define INIT_CRED(p) \ -{ \ - .usage = ATOMIC_INIT(3), \ - .securebits = SECUREBITS_DEFAULT, \ - .cap_inheritable = CAP_INIT_INH_SET, \ - .cap_permitted = CAP_FULL_SET, \ - .cap_effective = CAP_INIT_EFF_SET, \ - .cap_bset = CAP_INIT_BSET, \ - .user = INIT_USER, \ - .group_info = &init_groups, \ - .lock = __SPIN_LOCK_UNLOCKED(p.lock), \ -} - /* * INIT_TASK is used to set up the first task table, touch at * your own risk!. Base=0, limit=0x1fffff (=2MB) @@ -162,8 +149,7 @@ extern struct cred init_cred; .children = LIST_HEAD_INIT(tsk.children), \ .sibling = LIST_HEAD_INIT(tsk.sibling), \ .group_leader = &tsk, \ - .__temp_cred = INIT_CRED(tsk.__temp_cred), \ - .cred = &tsk.__temp_cred, \ + .cred = &init_cred, \ .comm = "swapper", \ .thread = INIT_THREAD, \ .fs = &init_fs, \ diff --git a/include/linux/sched.h b/include/linux/sched.h index c8b92502354d..740cf946c8cc 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1151,7 +1151,6 @@ struct task_struct { struct list_head cpu_timers[3]; /* process credentials */ - struct cred __temp_cred __deprecated; /* temporary credentials to be removed */ struct cred *cred; /* actual/objective task credentials */ char comm[TASK_COMM_LEN]; /* executable name excluding path diff --git a/include/linux/security.h b/include/linux/security.h index 9f305d4a31a7..9239cc11eb9c 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -593,15 +593,15 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * manual page for definitions of the @clone_flags. * @clone_flags contains the flags indicating what should be shared. * Return 0 if permission is granted. - * @task_alloc_security: - * @p contains the task_struct for child process. - * Allocate and attach a security structure to the p->security field. The - * security field is initialized to NULL when the task structure is + * @cred_alloc_security: + * @cred contains the cred struct for child process. + * Allocate and attach a security structure to the cred->security field. + * The security field is initialized to NULL when the task structure is * allocated. * Return 0 if operation was successful. - * @task_free_security: - * @p contains the task_struct for process. - * Deallocate and clear the p->security field. + * @cred_free: + * @cred points to the credentials. + * Deallocate and clear the cred->security field in a set of credentials. * @task_setuid: * Check permission before setting one or more of the user identity * attributes of the current process. The @flags parameter indicates @@ -1405,8 +1405,8 @@ struct security_operations { int (*dentry_open) (struct file *file); int (*task_create) (unsigned long clone_flags); - int (*task_alloc_security) (struct task_struct *p); - void (*task_free_security) (struct task_struct *p); + int (*cred_alloc_security) (struct cred *cred); + void (*cred_free) (struct cred *cred); int (*task_setuid) (uid_t id0, uid_t id1, uid_t id2, int flags); int (*task_post_setuid) (uid_t old_ruid /* or fsuid */ , uid_t old_euid, uid_t old_suid, int flags); @@ -1660,8 +1660,8 @@ int security_file_send_sigiotask(struct task_struct *tsk, int security_file_receive(struct file *file); int security_dentry_open(struct file *file); int security_task_create(unsigned long clone_flags); -int security_task_alloc(struct task_struct *p); -void security_task_free(struct task_struct *p); +int security_cred_alloc(struct cred *cred); +void security_cred_free(struct cred *cred); int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags); int security_task_post_setuid(uid_t old_ruid, uid_t old_euid, uid_t old_suid, int flags); @@ -2181,12 +2181,12 @@ static inline int security_task_create(unsigned long clone_flags) return 0; } -static inline int security_task_alloc(struct task_struct *p) +static inline int security_cred_alloc(struct cred *cred) { return 0; } -static inline void security_task_free(struct task_struct *p) +static inline void security_cred_free(struct cred *cred) { } static inline int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, diff --git a/kernel/Makefile b/kernel/Makefile index 9a3ec66a9d84..5a6a612c302d 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -9,7 +9,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o \ rcupdate.o extable.o params.o posix-timers.o \ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \ hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \ - notifier.o ksysfs.o pm_qos_params.o sched_clock.o + notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o CFLAGS_REMOVE_sched.o = -mno-spe diff --git a/kernel/cred.c b/kernel/cred.c new file mode 100644 index 000000000000..833244a7cb05 --- /dev/null +++ b/kernel/cred.c @@ -0,0 +1,96 @@ +/* Task credentials management + * + * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#include +#include +#include +#include +#include +#include +#include + +/* + * The initial credentials for the initial task + */ +struct cred init_cred = { + .usage = ATOMIC_INIT(3), + .securebits = SECUREBITS_DEFAULT, + .cap_inheritable = CAP_INIT_INH_SET, + .cap_permitted = CAP_FULL_SET, + .cap_effective = CAP_INIT_EFF_SET, + .cap_bset = CAP_INIT_BSET, + .user = INIT_USER, + .group_info = &init_groups, +}; + +/* + * The RCU callback to actually dispose of a set of credentials + */ +static void put_cred_rcu(struct rcu_head *rcu) +{ + struct cred *cred = container_of(rcu, struct cred, rcu); + + BUG_ON(atomic_read(&cred->usage) != 0); + + key_put(cred->thread_keyring); + key_put(cred->request_key_auth); + put_group_info(cred->group_info); + free_uid(cred->user); + security_cred_free(cred); + kfree(cred); +} + +/** + * __put_cred - Destroy a set of credentials + * @sec: The record to release + * + * Destroy a set of credentials on which no references remain. + */ +void __put_cred(struct cred *cred) +{ + call_rcu(&cred->rcu, put_cred_rcu); +} +EXPORT_SYMBOL(__put_cred); + +/* + * Copy credentials for the new process created by fork() + */ +int copy_creds(struct task_struct *p, unsigned long clone_flags) +{ + struct cred *pcred; + int ret; + + pcred = kmemdup(p->cred, sizeof(*p->cred), GFP_KERNEL); + if (!pcred) + return -ENOMEM; + +#ifdef CONFIG_SECURITY + pcred->security = NULL; +#endif + + ret = security_cred_alloc(pcred); + if (ret < 0) { + kfree(pcred); + return ret; + } + + atomic_set(&pcred->usage, 1); + get_group_info(pcred->group_info); + get_uid(pcred->user); + key_get(pcred->thread_keyring); + key_get(pcred->request_key_auth); + + atomic_inc(&pcred->user->processes); + + /* RCU assignment is unneeded here as no-one can have accessed this + * pointer yet, barring us */ + p->cred = pcred; + return 0; +} diff --git a/kernel/fork.c b/kernel/fork.c index 81fdc7733908..c932e283ddfc 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -146,9 +146,7 @@ void __put_task_struct(struct task_struct *tsk) WARN_ON(atomic_read(&tsk->usage)); WARN_ON(tsk == current); - security_task_free(tsk); - free_uid(tsk->__temp_cred.user); - put_group_info(tsk->__temp_cred.group_info); + put_cred(tsk->cred); delayacct_tsk_free(tsk); if (!profile_handoff_task(tsk)) @@ -969,7 +967,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled); DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled); #endif - p->cred = &p->__temp_cred; retval = -EAGAIN; if (atomic_read(&p->cred->user->processes) >= p->signal->rlim[RLIMIT_NPROC].rlim_cur) { @@ -978,9 +975,9 @@ static struct task_struct *copy_process(unsigned long clone_flags, goto bad_fork_free; } - atomic_inc(&p->cred->user->__count); - atomic_inc(&p->cred->user->processes); - get_group_info(p->cred->group_info); + retval = copy_creds(p, clone_flags); + if (retval < 0) + goto bad_fork_free; /* * If multiple threads are within copy_process(), then this check @@ -1035,9 +1032,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, do_posix_clock_monotonic_gettime(&p->start_time); p->real_start_time = p->start_time; monotonic_to_bootbased(&p->real_start_time); -#ifdef CONFIG_SECURITY - p->cred->security = NULL; -#endif p->io_context = NULL; p->audit_context = NULL; cgroup_fork(p); @@ -1082,10 +1076,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, /* Perform scheduler related setup. Assign this task to a CPU. */ sched_fork(p, clone_flags); - if ((retval = security_task_alloc(p))) - goto bad_fork_cleanup_policy; if ((retval = audit_alloc(p))) - goto bad_fork_cleanup_security; + goto bad_fork_cleanup_policy; /* copy all the process information */ if ((retval = copy_semundo(clone_flags, p))) goto bad_fork_cleanup_audit; @@ -1284,8 +1276,6 @@ bad_fork_cleanup_semundo: exit_sem(p); bad_fork_cleanup_audit: audit_free(p); -bad_fork_cleanup_security: - security_task_free(p); bad_fork_cleanup_policy: #ifdef CONFIG_NUMA mpol_put(p->mempolicy); @@ -1298,9 +1288,7 @@ bad_fork_cleanup_cgroup: bad_fork_cleanup_put_domain: module_put(task_thread_info(p)->exec_domain->module); bad_fork_cleanup_count: - put_group_info(p->cred->group_info); - atomic_dec(&p->cred->user->processes); - free_uid(p->cred->user); + put_cred(p->cred); bad_fork_free: free_task(p); fork_out: diff --git a/security/capability.c b/security/capability.c index 245874819036..6c4b5137ca7b 100644 --- a/security/capability.c +++ b/security/capability.c @@ -340,12 +340,12 @@ static int cap_task_create(unsigned long clone_flags) return 0; } -static int cap_task_alloc_security(struct task_struct *p) +static int cap_cred_alloc_security(struct cred *cred) { return 0; } -static void cap_task_free_security(struct task_struct *p) +static void cap_cred_free(struct cred *cred) { } @@ -890,8 +890,8 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, file_receive); set_to_cap_if_null(ops, dentry_open); set_to_cap_if_null(ops, task_create); - set_to_cap_if_null(ops, task_alloc_security); - set_to_cap_if_null(ops, task_free_security); + set_to_cap_if_null(ops, cred_alloc_security); + set_to_cap_if_null(ops, cred_free); set_to_cap_if_null(ops, task_setuid); set_to_cap_if_null(ops, task_post_setuid); set_to_cap_if_null(ops, task_setgid); diff --git a/security/security.c b/security/security.c index 81c956a12300..d058f7d5b10a 100644 --- a/security/security.c +++ b/security/security.c @@ -616,14 +616,14 @@ int security_task_create(unsigned long clone_flags) return security_ops->task_create(clone_flags); } -int security_task_alloc(struct task_struct *p) +int security_cred_alloc(struct cred *cred) { - return security_ops->task_alloc_security(p); + return security_ops->cred_alloc_security(cred); } -void security_task_free(struct task_struct *p) +void security_cred_free(struct cred *cred) { - security_ops->task_free_security(p); + security_ops->cred_free(cred); } int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 328308f2882a..658435dce37c 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -158,7 +158,7 @@ static int selinux_secmark_enabled(void) /* Allocate and free functions for each kind of security blob. */ -static int task_alloc_security(struct task_struct *task) +static int cred_alloc_security(struct cred *cred) { struct task_security_struct *tsec; @@ -167,18 +167,11 @@ static int task_alloc_security(struct task_struct *task) return -ENOMEM; tsec->osid = tsec->sid = SECINITSID_UNLABELED; - task->cred->security = tsec; + cred->security = tsec; return 0; } -static void task_free_security(struct task_struct *task) -{ - struct task_security_struct *tsec = task->cred->security; - task->cred->security = NULL; - kfree(tsec); -} - static int inode_alloc_security(struct inode *inode) { struct task_security_struct *tsec = current->cred->security; @@ -3184,17 +3177,17 @@ static int selinux_task_create(unsigned long clone_flags) return task_has_perm(current, current, PROCESS__FORK); } -static int selinux_task_alloc_security(struct task_struct *tsk) +static int selinux_cred_alloc_security(struct cred *cred) { struct task_security_struct *tsec1, *tsec2; int rc; tsec1 = current->cred->security; - rc = task_alloc_security(tsk); + rc = cred_alloc_security(cred); if (rc) return rc; - tsec2 = tsk->cred->security; + tsec2 = cred->security; tsec2->osid = tsec1->osid; tsec2->sid = tsec1->sid; @@ -3208,9 +3201,14 @@ static int selinux_task_alloc_security(struct task_struct *tsk) return 0; } -static void selinux_task_free_security(struct task_struct *tsk) +/* + * detach and free the LSM part of a set of credentials + */ +static void selinux_cred_free(struct cred *cred) { - task_free_security(tsk); + struct task_security_struct *tsec = cred->security; + cred->security = NULL; + kfree(tsec); } static int selinux_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) @@ -5552,8 +5550,8 @@ static struct security_operations selinux_ops = { .dentry_open = selinux_dentry_open, .task_create = selinux_task_create, - .task_alloc_security = selinux_task_alloc_security, - .task_free_security = selinux_task_free_security, + .cred_alloc_security = selinux_cred_alloc_security, + .cred_free = selinux_cred_free, .task_setuid = selinux_task_setuid, .task_post_setuid = selinux_task_post_setuid, .task_setgid = selinux_task_setgid, @@ -5683,7 +5681,7 @@ static __init int selinux_init(void) printk(KERN_INFO "SELinux: Initializing.\n"); /* Set the security state for the initial task. */ - if (task_alloc_security(current)) + if (cred_alloc_security(current->cred)) panic("SELinux: Failed to initialize initial task.\n"); tsec = current->cred->security; tsec->osid = tsec->sid = SECINITSID_KERNEL; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 791da238d049..cc837314fb0e 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -975,8 +975,8 @@ static int smack_file_receive(struct file *file) */ /** - * smack_task_alloc_security - "allocate" a task blob - * @tsk: the task in need of a blob + * smack_cred_alloc_security - "allocate" a task cred blob + * @cred: the task creds in need of a blob * * Smack isn't using copies of blobs. Everyone * points to an immutable list. No alloc required. @@ -984,24 +984,24 @@ static int smack_file_receive(struct file *file) * * Always returns 0 */ -static int smack_task_alloc_security(struct task_struct *tsk) +static int smack_cred_alloc_security(struct cred *cred) { - tsk->cred->security = current->cred->security; + cred->security = current->cred->security; return 0; } /** - * smack_task_free_security - "free" a task blob - * @task: the task with the blob + * smack_cred_free - "free" task-level security credentials + * @cred: the credentials in question * * Smack isn't using copies of blobs. Everyone * points to an immutable list. The blobs never go away. * There is no leak here. */ -static void smack_task_free_security(struct task_struct *task) +static void smack_cred_free(struct cred *cred) { - task->cred->security = NULL; + cred->security = NULL; } /** @@ -2630,8 +2630,8 @@ struct security_operations smack_ops = { .file_send_sigiotask = smack_file_send_sigiotask, .file_receive = smack_file_receive, - .task_alloc_security = smack_task_alloc_security, - .task_free_security = smack_task_free_security, + .cred_alloc_security = smack_cred_alloc_security, + .cred_free = smack_cred_free, .task_post_setuid = cap_task_post_setuid, .task_setpgid = smack_task_setpgid, .task_getpgid = smack_task_getpgid, -- cgit v1.2.3 From 86a264abe542cfececb4df129bc45a0338d8cdb9 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:18 +1100 Subject: CRED: Wrap current->cred and a few other accessors Wrap current->cred and a few other accessors to hide their actual implementation. Signed-off-by: David Howells Acked-by: James Morris Acked-by: Serge Hallyn Signed-off-by: James Morris --- arch/ia64/ia32/sys_ia32.c | 7 +- drivers/net/tun.c | 8 +- drivers/usb/core/devio.c | 10 ++- fs/binfmt_elf.c | 10 +-- fs/binfmt_elf_fdpic.c | 9 +- fs/exec.c | 5 +- fs/fcntl.c | 3 +- fs/file_table.c | 7 +- fs/hugetlbfs/inode.c | 5 +- fs/ioprio.c | 4 +- fs/smbfs/dir.c | 3 +- include/linux/cred.h | 187 ++++++++++++++++++++++++++++++++---------- include/linux/securebits.h | 2 +- ipc/mqueue.c | 2 +- ipc/shm.c | 4 +- kernel/sys.c | 59 +++++++------ kernel/uid16.c | 31 +++---- net/core/scm.c | 2 +- net/sunrpc/auth.c | 14 ++-- security/commoncap.c | 2 +- security/keys/process_keys.c | 2 +- security/keys/request_key.c | 11 +-- security/selinux/exports.c | 8 +- security/selinux/xfrm.c | 6 +- security/smack/smack_access.c | 2 +- security/smack/smack_lsm.c | 26 +++--- security/smack/smackfs.c | 4 +- 27 files changed, 271 insertions(+), 162 deletions(-) (limited to 'include') diff --git a/arch/ia64/ia32/sys_ia32.c b/arch/ia64/ia32/sys_ia32.c index 2445a9d3488e..16ef61a91d95 100644 --- a/arch/ia64/ia32/sys_ia32.c +++ b/arch/ia64/ia32/sys_ia32.c @@ -1767,25 +1767,24 @@ groups16_from_user(struct group_info *group_info, short __user *grouplist) asmlinkage long sys32_getgroups16 (int gidsetsize, short __user *grouplist) { + const struct cred *cred = current_cred(); int i; if (gidsetsize < 0) return -EINVAL; - get_group_info(current->cred->group_info); - i = current->cred->group_info->ngroups; + i = cred->group_info->ngroups; if (gidsetsize) { if (i > gidsetsize) { i = -EINVAL; goto out; } - if (groups16_to_user(grouplist, current->cred->group_info)) { + if (groups16_to_user(grouplist, cred->group_info)) { i = -EFAULT; goto out; } } out: - put_group_info(current->cred->group_info); return i; } diff --git a/drivers/net/tun.c b/drivers/net/tun.c index b14e2025e221..55dc70c6b4db 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -702,6 +702,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) struct tun_net *tn; struct tun_struct *tun; struct net_device *dev; + const struct cred *cred = current_cred(); int err; tn = net_generic(net, tun_net_id); @@ -712,11 +713,12 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) /* Check permissions */ if (((tun->owner != -1 && - current_euid() != tun->owner) || + cred->euid != tun->owner) || (tun->group != -1 && - current_egid() != tun->group)) && - !capable(CAP_NET_ADMIN)) + cred->egid != tun->group)) && + !capable(CAP_NET_ADMIN)) { return -EPERM; + } } else if (__dev_get_by_name(net, ifr->ifr_name)) return -EINVAL; diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 1aadb9387027..aa79280df15d 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -574,6 +574,7 @@ static int usbdev_open(struct inode *inode, struct file *file) { struct usb_device *dev = NULL; struct dev_state *ps; + const struct cred *cred = current_cred(); int ret; lock_kernel(); @@ -617,8 +618,8 @@ static int usbdev_open(struct inode *inode, struct file *file) init_waitqueue_head(&ps->wait); ps->discsignr = 0; ps->disc_pid = get_pid(task_pid(current)); - ps->disc_uid = current_uid(); - ps->disc_euid = current_euid(); + ps->disc_uid = cred->uid; + ps->disc_euid = cred->euid; ps->disccontext = NULL; ps->ifclaimed = 0; security_task_getsecid(current, &ps->secid); @@ -967,6 +968,7 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb, struct usb_host_endpoint *ep; struct async *as; struct usb_ctrlrequest *dr = NULL; + const struct cred *cred = current_cred(); unsigned int u, totlen, isofrmlen; int ret, ifnum = -1; int is_in; @@ -1174,8 +1176,8 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb, as->signr = uurb->signr; as->ifnum = ifnum; as->pid = get_pid(task_pid(current)); - as->uid = current_uid(); - as->euid = current_euid(); + as->uid = cred->uid; + as->euid = cred->euid; security_task_getsecid(current, &as->secid); if (!is_in) { if (copy_from_user(as->urb->transfer_buffer, uurb->buffer, diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 7a52477ce493..0e6655613169 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -157,7 +157,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, int items; elf_addr_t *elf_info; int ei_index = 0; - struct task_struct *tsk = current; + const struct cred *cred = current_cred(); struct vm_area_struct *vma; /* @@ -223,10 +223,10 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, NEW_AUX_ENT(AT_BASE, interp_load_addr); NEW_AUX_ENT(AT_FLAGS, 0); NEW_AUX_ENT(AT_ENTRY, exec->e_entry); - NEW_AUX_ENT(AT_UID, tsk->cred->uid); - NEW_AUX_ENT(AT_EUID, tsk->cred->euid); - NEW_AUX_ENT(AT_GID, tsk->cred->gid); - NEW_AUX_ENT(AT_EGID, tsk->cred->egid); + NEW_AUX_ENT(AT_UID, cred->uid); + NEW_AUX_ENT(AT_EUID, cred->euid); + NEW_AUX_ENT(AT_GID, cred->gid); + NEW_AUX_ENT(AT_EGID, cred->egid); NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); NEW_AUX_ENT(AT_EXECFN, bprm->exec); if (k_platform) { diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 9f67054c2c4e..1f6e8c023b4c 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -475,6 +475,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, struct elf_fdpic_params *exec_params, struct elf_fdpic_params *interp_params) { + const struct cred *cred = current_cred(); unsigned long sp, csp, nitems; elf_caddr_t __user *argv, *envp; size_t platform_len = 0, len; @@ -623,10 +624,10 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); NEW_AUX_ENT(AT_FLAGS, 0); NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); - NEW_AUX_ENT(AT_UID, (elf_addr_t) current->cred->uid); - NEW_AUX_ENT(AT_EUID, (elf_addr_t) current->cred->euid); - NEW_AUX_ENT(AT_GID, (elf_addr_t) current->cred->gid); - NEW_AUX_ENT(AT_EGID, (elf_addr_t) current->cred->egid); + NEW_AUX_ENT(AT_UID, (elf_addr_t) cred->uid); + NEW_AUX_ENT(AT_EUID, (elf_addr_t) cred->euid); + NEW_AUX_ENT(AT_GID, (elf_addr_t) cred->gid); + NEW_AUX_ENT(AT_EGID, (elf_addr_t) cred->egid); NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); NEW_AUX_ENT(AT_EXECFN, bprm->exec); diff --git a/fs/exec.c b/fs/exec.c index 31149e430a89..a5330e1a2216 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1388,6 +1388,7 @@ EXPORT_SYMBOL(set_binfmt); */ static int format_corename(char *corename, long signr) { + const struct cred *cred = current_cred(); const char *pat_ptr = core_pattern; int ispipe = (*pat_ptr == '|'); char *out_ptr = corename; @@ -1424,7 +1425,7 @@ static int format_corename(char *corename, long signr) /* uid */ case 'u': rc = snprintf(out_ptr, out_end - out_ptr, - "%d", current_uid()); + "%d", cred->uid); if (rc > out_end - out_ptr) goto out; out_ptr += rc; @@ -1432,7 +1433,7 @@ static int format_corename(char *corename, long signr) /* gid */ case 'g': rc = snprintf(out_ptr, out_end - out_ptr, - "%d", current_gid()); + "%d", cred->gid); if (rc > out_end - out_ptr) goto out; out_ptr += rc; diff --git a/fs/fcntl.c b/fs/fcntl.c index 63964d863ad6..c594cc0e40fb 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -205,13 +205,14 @@ static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, int __f_setown(struct file *filp, struct pid *pid, enum pid_type type, int force) { + const struct cred *cred = current_cred(); int err; err = security_file_set_fowner(filp); if (err) return err; - f_modown(filp, pid, type, current_uid(), current_euid(), force); + f_modown(filp, pid, type, cred->uid, cred->euid, force); return 0; } EXPORT_SYMBOL(__f_setown); diff --git a/fs/file_table.c b/fs/file_table.c index 3152b53cfab0..bc4563fe791d 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -94,7 +94,7 @@ int proc_nr_files(ctl_table *table, int write, struct file *filp, */ struct file *get_empty_filp(void) { - struct task_struct *tsk; + const struct cred *cred = current_cred(); static int old_max; struct file * f; @@ -118,12 +118,11 @@ struct file *get_empty_filp(void) if (security_file_alloc(f)) goto fail_sec; - tsk = current; INIT_LIST_HEAD(&f->f_u.fu_list); atomic_long_set(&f->f_count, 1); rwlock_init(&f->f_owner.lock); - f->f_uid = tsk->cred->fsuid; - f->f_gid = tsk->cred->fsgid; + f->f_uid = cred->fsuid; + f->f_gid = cred->fsgid; eventpoll_init_file(f); /* f->f_version: 0 */ return f; diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 870a721b8bd2..7d479ce3aceb 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -951,6 +951,7 @@ struct file *hugetlb_file_setup(const char *name, size_t size) struct inode *inode; struct dentry *dentry, *root; struct qstr quick_string; + struct user_struct *user = current_user(); if (!hugetlbfs_vfsmount) return ERR_PTR(-ENOENT); @@ -958,7 +959,7 @@ struct file *hugetlb_file_setup(const char *name, size_t size) if (!can_do_hugetlb_shm()) return ERR_PTR(-EPERM); - if (!user_shm_lock(size, current->cred->user)) + if (!user_shm_lock(size, user)) return ERR_PTR(-ENOMEM); root = hugetlbfs_vfsmount->mnt_root; @@ -998,7 +999,7 @@ out_inode: out_dentry: dput(dentry); out_shm_unlock: - user_shm_unlock(size, current->cred->user); + user_shm_unlock(size, user); return ERR_PTR(error); } diff --git a/fs/ioprio.c b/fs/ioprio.c index bb5210af77c2..5112554fd210 100644 --- a/fs/ioprio.c +++ b/fs/ioprio.c @@ -123,7 +123,7 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio) break; case IOPRIO_WHO_USER: if (!who) - user = current->cred->user; + user = current_user(); else user = find_user(who); @@ -216,7 +216,7 @@ asmlinkage long sys_ioprio_get(int which, int who) break; case IOPRIO_WHO_USER: if (!who) - user = current->cred->user; + user = current_user(); else user = find_user(who); diff --git a/fs/smbfs/dir.c b/fs/smbfs/dir.c index 9e9bb0db4f6d..e7ddd0328ddc 100644 --- a/fs/smbfs/dir.c +++ b/fs/smbfs/dir.c @@ -667,8 +667,7 @@ smb_make_node(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) attr.ia_valid = ATTR_MODE | ATTR_UID | ATTR_GID; attr.ia_mode = mode; - attr.ia_uid = current_euid(); - attr.ia_gid = current_egid(); + current_euid_egid(&attr.ia_uid, &attr.ia_gid); if (!new_valid_dev(dev)) return -EINVAL; diff --git a/include/linux/cred.h b/include/linux/cred.h index a7a686074cb0..4221ec6000c1 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -37,15 +37,16 @@ struct group_info { * get_group_info - Get a reference to a group info structure * @group_info: The group info to reference * - * This must be called with the owning task locked (via task_lock()) when task - * != current. The reason being that the vast majority of callers are looking - * at current->group_info, which can not be changed except by the current task. - * Changing current->group_info requires the task lock, too. + * This gets a reference to a set of supplementary groups. + * + * If the caller is accessing a task's credentials, they must hold the RCU read + * lock when reading. */ -#define get_group_info(group_info) \ -do { \ - atomic_inc(&(group_info)->usage); \ -} while (0) +static inline struct group_info *get_group_info(struct group_info *gi) +{ + atomic_inc(&gi->usage); + return gi; +} /** * put_group_info - Release a reference to a group info structure @@ -61,7 +62,7 @@ extern struct group_info *groups_alloc(int); extern void groups_free(struct group_info *); extern int set_current_groups(struct group_info *); extern int set_groups(struct cred *, struct group_info *); -extern int groups_search(struct group_info *, gid_t); +extern int groups_search(const struct group_info *, gid_t); /* access the groups "array" with this macro */ #define GROUP_AT(gi, i) \ @@ -123,41 +124,6 @@ struct cred { spinlock_t lock; /* lock for pointer changes */ }; -#define get_current_user() (get_uid(current->cred->user)) - -#define task_uid(task) ((task)->cred->uid) -#define task_gid(task) ((task)->cred->gid) -#define task_euid(task) ((task)->cred->euid) -#define task_egid(task) ((task)->cred->egid) - -#define current_uid() (current->cred->uid) -#define current_gid() (current->cred->gid) -#define current_euid() (current->cred->euid) -#define current_egid() (current->cred->egid) -#define current_suid() (current->cred->suid) -#define current_sgid() (current->cred->sgid) -#define current_fsuid() (current->cred->fsuid) -#define current_fsgid() (current->cred->fsgid) -#define current_cap() (current->cred->cap_effective) - -#define current_uid_gid(_uid, _gid) \ -do { \ - *(_uid) = current->cred->uid; \ - *(_gid) = current->cred->gid; \ -} while(0) - -#define current_euid_egid(_uid, _gid) \ -do { \ - *(_uid) = current->cred->euid; \ - *(_gid) = current->cred->egid; \ -} while(0) - -#define current_fsuid_fsgid(_uid, _gid) \ -do { \ - *(_uid) = current->cred->fsuid; \ - *(_gid) = current->cred->fsgid; \ -} while(0) - extern void __put_cred(struct cred *); extern int copy_creds(struct task_struct *, unsigned long); @@ -187,4 +153,137 @@ static inline void put_cred(struct cred *cred) __put_cred(cred); } +/** + * current_cred - Access the current task's credentials + * + * Access the credentials of the current task. + */ +#define current_cred() \ + (current->cred) + +/** + * __task_cred - Access another task's credentials + * @task: The task to query + * + * Access the credentials of another task. The caller must hold the + * RCU readlock. + * + * The caller must make sure task doesn't go away, either by holding a ref on + * task or by holding tasklist_lock to prevent it from being unlinked. + */ +#define __task_cred(task) \ + ((const struct cred *)(rcu_dereference((task)->cred))) + +/** + * get_task_cred - Get another task's credentials + * @task: The task to query + * + * Get the credentials of a task, pinning them so that they can't go away. + * Accessing a task's credentials directly is not permitted. + * + * The caller must make sure task doesn't go away, either by holding a ref on + * task or by holding tasklist_lock to prevent it from being unlinked. + */ +#define get_task_cred(task) \ +({ \ + struct cred *__cred; \ + rcu_read_lock(); \ + __cred = (struct cred *) __task_cred((task)); \ + get_cred(__cred); \ + rcu_read_unlock(); \ + __cred; \ +}) + +/** + * get_current_cred - Get the current task's credentials + * + * Get the credentials of the current task, pinning them so that they can't go + * away. Accessing the current task's credentials directly is not permitted. + */ +#define get_current_cred() \ + (get_cred(current_cred())) + +/** + * get_current_user - Get the current task's user_struct + * + * Get the user record of the current task, pinning it so that it can't go + * away. + */ +#define get_current_user() \ +({ \ + struct user_struct *__u; \ + struct cred *__cred; \ + __cred = (struct cred *) current_cred(); \ + __u = get_uid(__cred->user); \ + __u; \ +}) + +/** + * get_current_groups - Get the current task's supplementary group list + * + * Get the supplementary group list of the current task, pinning it so that it + * can't go away. + */ +#define get_current_groups() \ +({ \ + struct group_info *__groups; \ + struct cred *__cred; \ + __cred = (struct cred *) current_cred(); \ + __groups = get_group_info(__cred->group_info); \ + __groups; \ +}) + +#define task_cred_xxx(task, xxx) \ +({ \ + __typeof__(task->cred->xxx) ___val; \ + rcu_read_lock(); \ + ___val = __task_cred((task))->xxx; \ + rcu_read_unlock(); \ + ___val; \ +}) + +#define task_uid(task) (task_cred_xxx((task), uid)) +#define task_euid(task) (task_cred_xxx((task), euid)) + +#define current_cred_xxx(xxx) \ +({ \ + current->cred->xxx; \ +}) + +#define current_uid() (current_cred_xxx(uid)) +#define current_gid() (current_cred_xxx(gid)) +#define current_euid() (current_cred_xxx(euid)) +#define current_egid() (current_cred_xxx(egid)) +#define current_suid() (current_cred_xxx(suid)) +#define current_sgid() (current_cred_xxx(sgid)) +#define current_fsuid() (current_cred_xxx(fsuid)) +#define current_fsgid() (current_cred_xxx(fsgid)) +#define current_cap() (current_cred_xxx(cap_effective)) +#define current_user() (current_cred_xxx(user)) +#define current_security() (current_cred_xxx(security)) + +#define current_uid_gid(_uid, _gid) \ +do { \ + const struct cred *__cred; \ + __cred = current_cred(); \ + *(_uid) = __cred->uid; \ + *(_gid) = __cred->gid; \ +} while(0) + +#define current_euid_egid(_euid, _egid) \ +do { \ + const struct cred *__cred; \ + __cred = current_cred(); \ + *(_euid) = __cred->euid; \ + *(_egid) = __cred->egid; \ +} while(0) + +#define current_fsuid_fsgid(_fsuid, _fsgid) \ +do { \ + const struct cred *__cred; \ + __cred = current_cred(); \ + *(_fsuid) = __cred->fsuid; \ + *(_fsgid) = __cred->fsgid; \ +} while(0) + #endif /* _LINUX_CRED_H */ diff --git a/include/linux/securebits.h b/include/linux/securebits.h index 6d389491bfa2..d2c5ed845bcc 100644 --- a/include/linux/securebits.h +++ b/include/linux/securebits.h @@ -32,7 +32,7 @@ setting is locked or not. A setting which is locked cannot be changed from user-level. */ #define issecure_mask(X) (1 << (X)) -#define issecure(X) (issecure_mask(X) & current->cred->securebits) +#define issecure(X) (issecure_mask(X) & current_cred_xxx(securebits)) #define SECURE_ALL_BITS (issecure_mask(SECURE_NOROOT) | \ issecure_mask(SECURE_NO_SETUID_FIXUP) | \ diff --git a/ipc/mqueue.c b/ipc/mqueue.c index e1885b494bac..1151881ccb9a 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -112,6 +112,7 @@ static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) static struct inode *mqueue_get_inode(struct super_block *sb, int mode, struct mq_attr *attr) { + struct user_struct *u = current_user(); struct inode *inode; inode = new_inode(sb); @@ -126,7 +127,6 @@ static struct inode *mqueue_get_inode(struct super_block *sb, int mode, if (S_ISREG(mode)) { struct mqueue_inode_info *info; struct task_struct *p = current; - struct user_struct *u = p->cred->user; unsigned long mq_bytes, mq_msg_tblsz; inode->i_fop = &mqueue_file_operations; diff --git a/ipc/shm.c b/ipc/shm.c index 264a9d33c5dd..38a055758a9b 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -366,7 +366,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) if (shmflg & SHM_HUGETLB) { /* hugetlb_file_setup takes care of mlock user accounting */ file = hugetlb_file_setup(name, size); - shp->mlock_user = current->cred->user; + shp->mlock_user = current_user(); } else { int acctflag = VM_ACCOUNT; /* @@ -767,7 +767,7 @@ asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf) goto out_unlock; if(cmd==SHM_LOCK) { - struct user_struct *user = current->cred->user; + struct user_struct *user = current_user(); if (!is_file_hugepages(shp->shm_file)) { err = shmem_lock(shp->shm_file, 1, user); if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ diff --git a/kernel/sys.c b/kernel/sys.c index 5d81f07c0150..c4d6b59553e9 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -143,6 +143,7 @@ asmlinkage long sys_setpriority(int which, int who, int niceval) { struct task_struct *g, *p; struct user_struct *user; + const struct cred *cred = current_cred(); int error = -EINVAL; struct pid *pgrp; @@ -176,18 +177,18 @@ asmlinkage long sys_setpriority(int which, int who, int niceval) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: - user = current->cred->user; + user = cred->user; if (!who) - who = current_uid(); - else - if (who != current_uid() && !(user = find_user(who))) - goto out_unlock; /* No processes for this user */ + who = cred->uid; + else if ((who != cred->uid) && + !(user = find_user(who))) + goto out_unlock; /* No processes for this user */ do_each_thread(g, p) - if (p->cred->uid == who) + if (__task_cred(p)->uid == who) error = set_one_prio(p, niceval, error); while_each_thread(g, p); - if (who != current_uid()) + if (who != cred->uid) free_uid(user); /* For find_user() */ break; } @@ -207,6 +208,7 @@ asmlinkage long sys_getpriority(int which, int who) { struct task_struct *g, *p; struct user_struct *user; + const struct cred *cred = current_cred(); long niceval, retval = -ESRCH; struct pid *pgrp; @@ -238,21 +240,21 @@ asmlinkage long sys_getpriority(int which, int who) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: - user = current->cred->user; + user = (struct user_struct *) cred->user; if (!who) - who = current_uid(); - else - if (who != current_uid() && !(user = find_user(who))) - goto out_unlock; /* No processes for this user */ + who = cred->uid; + else if ((who != cred->uid) && + !(user = find_user(who))) + goto out_unlock; /* No processes for this user */ do_each_thread(g, p) - if (p->cred->uid == who) { + if (__task_cred(p)->uid == who) { niceval = 20 - task_nice(p); if (niceval > retval) retval = niceval; } while_each_thread(g, p); - if (who != current_uid()) + if (who != cred->uid) free_uid(user); /* for find_user() */ break; } @@ -743,11 +745,11 @@ asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid) { - struct cred *cred = current->cred; + const struct cred *cred = current_cred(); int retval; - if (!(retval = put_user(cred->uid, ruid)) && - !(retval = put_user(cred->euid, euid))) + if (!(retval = put_user(cred->uid, ruid)) && + !(retval = put_user(cred->euid, euid))) retval = put_user(cred->suid, suid); return retval; @@ -796,11 +798,11 @@ asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid) { - struct cred *cred = current->cred; + const struct cred *cred = current_cred(); int retval; - if (!(retval = put_user(cred->gid, rgid)) && - !(retval = put_user(cred->egid, egid))) + if (!(retval = put_user(cred->gid, rgid)) && + !(retval = put_user(cred->egid, egid))) retval = put_user(cred->sgid, sgid); return retval; @@ -1199,7 +1201,7 @@ static void groups_sort(struct group_info *group_info) } /* a simple bsearch */ -int groups_search(struct group_info *group_info, gid_t grp) +int groups_search(const struct group_info *group_info, gid_t grp) { unsigned int left, right; @@ -1268,13 +1270,8 @@ EXPORT_SYMBOL(set_current_groups); asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist) { - struct cred *cred = current->cred; - int i = 0; - - /* - * SMP: Nobody else can change our grouplist. Thus we are - * safe. - */ + const struct cred *cred = current_cred(); + int i; if (gidsetsize < 0) return -EINVAL; @@ -1330,8 +1327,9 @@ asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist) */ int in_group_p(gid_t grp) { - struct cred *cred = current->cred; + const struct cred *cred = current_cred(); int retval = 1; + if (grp != cred->fsgid) retval = groups_search(cred->group_info, grp); return retval; @@ -1341,8 +1339,9 @@ EXPORT_SYMBOL(in_group_p); int in_egroup_p(gid_t grp) { - struct cred *cred = current->cred; + const struct cred *cred = current_cred(); int retval = 1; + if (grp != cred->egid) retval = groups_search(cred->group_info, grp); return retval; diff --git a/kernel/uid16.c b/kernel/uid16.c index 71f07fc39fea..2460c3199b5a 100644 --- a/kernel/uid16.c +++ b/kernel/uid16.c @@ -84,11 +84,12 @@ asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid) asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, old_uid_t __user *suid) { + const struct cred *cred = current_cred(); int retval; - if (!(retval = put_user(high2lowuid(current->cred->uid), ruid)) && - !(retval = put_user(high2lowuid(current->cred->euid), euid))) - retval = put_user(high2lowuid(current->cred->suid), suid); + if (!(retval = put_user(high2lowuid(cred->uid), ruid)) && + !(retval = put_user(high2lowuid(cred->euid), euid))) + retval = put_user(high2lowuid(cred->suid), suid); return retval; } @@ -104,11 +105,12 @@ asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid) asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, old_gid_t __user *sgid) { + const struct cred *cred = current_cred(); int retval; - if (!(retval = put_user(high2lowgid(current->cred->gid), rgid)) && - !(retval = put_user(high2lowgid(current->cred->egid), egid))) - retval = put_user(high2lowgid(current->cred->sgid), sgid); + if (!(retval = put_user(high2lowgid(cred->gid), rgid)) && + !(retval = put_user(high2lowgid(cred->egid), egid))) + retval = put_user(high2lowgid(cred->sgid), sgid); return retval; } @@ -161,25 +163,24 @@ static int groups16_from_user(struct group_info *group_info, asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist) { - int i = 0; + const struct cred *cred = current_cred(); + int i; if (gidsetsize < 0) return -EINVAL; - get_group_info(current->cred->group_info); - i = current->cred->group_info->ngroups; + i = cred->group_info->ngroups; if (gidsetsize) { if (i > gidsetsize) { i = -EINVAL; goto out; } - if (groups16_to_user(grouplist, current->cred->group_info)) { + if (groups16_to_user(grouplist, cred->group_info)) { i = -EFAULT; goto out; } } out: - put_group_info(current->cred->group_info); return i; } @@ -210,20 +211,20 @@ asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist) asmlinkage long sys_getuid16(void) { - return high2lowuid(current->cred->uid); + return high2lowuid(current_uid()); } asmlinkage long sys_geteuid16(void) { - return high2lowuid(current->cred->euid); + return high2lowuid(current_euid()); } asmlinkage long sys_getgid16(void) { - return high2lowgid(current->cred->gid); + return high2lowgid(current_gid()); } asmlinkage long sys_getegid16(void) { - return high2lowgid(current->cred->egid); + return high2lowgid(current_egid()); } diff --git a/net/core/scm.c b/net/core/scm.c index c28ca32a7d93..f73c44b17dda 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -44,7 +44,7 @@ static __inline__ int scm_check_creds(struct ucred *creds) { - struct cred *cred = current->cred; + const struct cred *cred = current_cred(); if ((creds->pid == task_tgid_vnr(current) || capable(CAP_SYS_ADMIN)) && ((creds->uid == cred->uid || creds->uid == cred->euid || diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index c79543212602..0443f8349458 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -350,16 +350,18 @@ EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache); struct rpc_cred * rpcauth_lookupcred(struct rpc_auth *auth, int flags) { - struct auth_cred acred = { - .uid = current_fsuid(), - .gid = current_fsgid(), - .group_info = current->cred->group_info, - }; + struct auth_cred acred; struct rpc_cred *ret; + const struct cred *cred = current_cred(); dprintk("RPC: looking up %s cred\n", auth->au_ops->au_name); - get_group_info(acred.group_info); + + memset(&acred, 0, sizeof(acred)); + acred.uid = cred->fsuid; + acred.gid = cred->fsgid; + acred.group_info = get_group_info(((struct cred *)cred)->group_info); + ret = auth->au_ops->lookup_cred(auth, &acred, flags); put_group_info(acred.group_info); return ret; diff --git a/security/commoncap.c b/security/commoncap.c index fa61679f8c73..61307f590003 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -641,7 +641,7 @@ int cap_task_setnice (struct task_struct *p, int nice) int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5, long *rc_p) { - struct cred *cred = current->cred; + struct cred *cred = current_cred(); long error = 0; switch (option) { diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index b0904cdda2e7..ce8ac6073d57 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -582,7 +582,7 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, { struct request_key_auth *rka; struct task_struct *t = current; - struct cred *cred = t->cred; + struct cred *cred = current_cred(); struct key *key; key_ref_t key_ref, skey_ref; int ret; diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 3e9b9eb1dd28..0488b0af5bd6 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -67,6 +67,7 @@ static int call_sbin_request_key(struct key_construction *cons, void *aux) { struct task_struct *tsk = current; + const struct cred *cred = current_cred(); key_serial_t prkey, sskey; struct key *key = cons->key, *authkey = cons->authkey, *keyring; char *argv[9], *envp[3], uid_str[12], gid_str[12]; @@ -96,16 +97,16 @@ static int call_sbin_request_key(struct key_construction *cons, goto error_link; /* record the UID and GID */ - sprintf(uid_str, "%d", current_fsuid()); - sprintf(gid_str, "%d", current_fsgid()); + sprintf(uid_str, "%d", cred->fsuid); + sprintf(gid_str, "%d", cred->fsgid); /* we say which key is under construction */ sprintf(key_str, "%d", key->serial); /* we specify the process's default keyrings */ sprintf(keyring_str[0], "%d", - tsk->cred->thread_keyring ? - tsk->cred->thread_keyring->serial : 0); + cred->thread_keyring ? + cred->thread_keyring->serial : 0); prkey = 0; if (tsk->signal->process_keyring) @@ -118,7 +119,7 @@ static int call_sbin_request_key(struct key_construction *cons, sskey = rcu_dereference(tsk->signal->session_keyring)->serial; rcu_read_unlock(); } else { - sskey = tsk->cred->user->session_keyring->serial; + sskey = cred->user->session_keyring->serial; } sprintf(keyring_str[2], "%d", sskey); diff --git a/security/selinux/exports.c b/security/selinux/exports.c index cf02490cd1eb..c73aeaa008e8 100644 --- a/security/selinux/exports.c +++ b/security/selinux/exports.c @@ -39,9 +39,13 @@ EXPORT_SYMBOL_GPL(selinux_string_to_sid); int selinux_secmark_relabel_packet_permission(u32 sid) { if (selinux_enabled) { - struct task_security_struct *tsec = current->cred->security; + const struct task_security_struct *__tsec; + u32 tsid; - return avc_has_perm(tsec->sid, sid, SECCLASS_PACKET, + __tsec = current_security(); + tsid = __tsec->sid; + + return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL); } return 0; diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c index d7db76617b0e..c0eb72013d67 100644 --- a/security/selinux/xfrm.c +++ b/security/selinux/xfrm.c @@ -197,7 +197,7 @@ static int selinux_xfrm_sec_ctx_alloc(struct xfrm_sec_ctx **ctxp, struct xfrm_user_sec_ctx *uctx, u32 sid) { int rc = 0; - struct task_security_struct *tsec = current->cred->security; + const struct task_security_struct *tsec = current_security(); struct xfrm_sec_ctx *ctx = NULL; char *ctx_str = NULL; u32 str_len; @@ -333,7 +333,7 @@ void selinux_xfrm_policy_free(struct xfrm_sec_ctx *ctx) */ int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx) { - struct task_security_struct *tsec = current->cred->security; + const struct task_security_struct *tsec = current_security(); int rc = 0; if (ctx) { @@ -378,7 +378,7 @@ void selinux_xfrm_state_free(struct xfrm_state *x) */ int selinux_xfrm_state_delete(struct xfrm_state *x) { - struct task_security_struct *tsec = current->cred->security; + const struct task_security_struct *tsec = current_security(); struct xfrm_sec_ctx *ctx = x->security; int rc = 0; diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index b6dd4fc0fb0b..247cec3b5a43 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -164,7 +164,7 @@ int smk_curacc(char *obj_label, u32 mode) { int rc; - rc = smk_access(current->cred->security, obj_label, mode); + rc = smk_access(current_security(), obj_label, mode); if (rc == 0) return 0; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index cc837314fb0e..e8a4fcb1ad04 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -143,7 +143,7 @@ static int smack_ptrace_traceme(struct task_struct *ptp) static int smack_syslog(int type) { int rc; - char *sp = current->cred->security; + char *sp = current_security(); rc = cap_syslog(type); if (rc != 0) @@ -375,7 +375,7 @@ static int smack_sb_umount(struct vfsmount *mnt, int flags) */ static int smack_inode_alloc_security(struct inode *inode) { - inode->i_security = new_inode_smack(current->cred->security); + inode->i_security = new_inode_smack(current_security()); if (inode->i_security == NULL) return -ENOMEM; return 0; @@ -820,7 +820,7 @@ static int smack_file_permission(struct file *file, int mask) */ static int smack_file_alloc_security(struct file *file) { - file->f_security = current->cred->security; + file->f_security = current_security(); return 0; } @@ -918,7 +918,7 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd, */ static int smack_file_set_fowner(struct file *file) { - file->f_security = current->cred->security; + file->f_security = current_security(); return 0; } @@ -986,8 +986,7 @@ static int smack_file_receive(struct file *file) */ static int smack_cred_alloc_security(struct cred *cred) { - cred->security = current->cred->security; - + cred->security = current_security(); return 0; } @@ -1225,7 +1224,7 @@ static void smack_task_to_inode(struct task_struct *p, struct inode *inode) */ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) { - char *csp = current->cred->security; + char *csp = current_security(); struct socket_smack *ssp; ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); @@ -1450,7 +1449,7 @@ static int smack_flags_to_may(int flags) */ static int smack_msg_msg_alloc_security(struct msg_msg *msg) { - msg->security = current->cred->security; + msg->security = current_security(); return 0; } @@ -1486,7 +1485,7 @@ static int smack_shm_alloc_security(struct shmid_kernel *shp) { struct kern_ipc_perm *isp = &shp->shm_perm; - isp->security = current->cred->security; + isp->security = current_security(); return 0; } @@ -1595,7 +1594,7 @@ static int smack_sem_alloc_security(struct sem_array *sma) { struct kern_ipc_perm *isp = &sma->sem_perm; - isp->security = current->cred->security; + isp->security = current_security(); return 0; } @@ -1699,7 +1698,7 @@ static int smack_msg_queue_alloc_security(struct msg_queue *msq) { struct kern_ipc_perm *kisp = &msq->q_perm; - kisp->security = current->cred->security; + kisp->security = current_security(); return 0; } @@ -1854,7 +1853,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) struct super_block *sbp; struct superblock_smack *sbsp; struct inode_smack *isp; - char *csp = current->cred->security; + char *csp = current_security(); char *fetched; char *final; struct dentry *dp; @@ -2290,8 +2289,7 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent) return; ssp = sk->sk_security; - ssp->smk_in = current->cred->security; - ssp->smk_out = current->cred->security; + ssp->smk_in = ssp->smk_out = current_security(); ssp->smk_packet[0] = '\0'; rc = smack_netlabel(sk); diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index c5ca279e0506..ca257dfdc75d 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -336,7 +336,7 @@ static void smk_cipso_doi(void) audit_info.loginuid = audit_get_loginuid(current); audit_info.sessionid = audit_get_sessionid(current); - audit_info.secid = smack_to_secid(current->cred->security); + audit_info.secid = smack_to_secid(current_security()); rc = netlbl_cfg_map_del(NULL, &audit_info); if (rc != 0) @@ -371,7 +371,7 @@ static void smk_unlbl_ambient(char *oldambient) audit_info.loginuid = audit_get_loginuid(current); audit_info.sessionid = audit_get_sessionid(current); - audit_info.secid = smack_to_secid(current->cred->security); + audit_info.secid = smack_to_secid(current_security()); if (oldambient != NULL) { rc = netlbl_cfg_map_del(oldambient, &audit_info); -- cgit v1.2.3 From c69e8d9c01db2adc503464993c358901c9af9de4 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:19 +1100 Subject: CRED: Use RCU to access another task's creds and to release a task's own creds Use RCU to access another task's creds and to release a task's own creds. This means that it will be possible for the credentials of a task to be replaced without another task (a) requiring a full lock to read them, and (b) seeing deallocated memory. Signed-off-by: David Howells Acked-by: James Morris Acked-by: Serge Hallyn Signed-off-by: James Morris --- arch/ia64/kernel/perfmon.c | 32 +++++++++++++--------- drivers/connector/cn_proc.c | 16 +++++++---- fs/binfmt_elf.c | 8 ++++-- fs/binfmt_elf_fdpic.c | 8 ++++-- fs/fcntl.c | 15 ++++++++--- fs/fuse/dir.c | 23 ++++++++++------ fs/ioprio.c | 14 +++++++--- fs/proc/array.c | 32 ++++++++++++++-------- fs/proc/base.c | 32 ++++++++++++++++------ include/linux/cred.h | 3 ++- kernel/auditsc.c | 33 +++++++++++++---------- kernel/cgroup.c | 16 +++++------ kernel/exit.c | 14 ++++++---- kernel/futex.c | 22 +++++++++------ kernel/futex_compat.c | 7 ++--- kernel/ptrace.c | 22 ++++++++------- kernel/sched.c | 31 ++++++++++++++------- kernel/signal.c | 49 ++++++++++++++++++++------------- kernel/sys.c | 11 +++++--- kernel/tsacct.c | 6 +++-- mm/mempolicy.c | 8 +++--- mm/migrate.c | 8 +++--- mm/oom_kill.c | 6 ++--- security/commoncap.c | 64 +++++++++++++++++++++++++++----------------- security/keys/permission.c | 10 ++++--- security/keys/process_keys.c | 24 ++++++++++------- security/selinux/selinuxfs.c | 13 ++++++--- security/smack/smack_lsm.c | 32 +++++++++++----------- 28 files changed, 355 insertions(+), 204 deletions(-) (limited to 'include') diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c index dd38db46a77a..0e499757309b 100644 --- a/arch/ia64/kernel/perfmon.c +++ b/arch/ia64/kernel/perfmon.c @@ -2399,25 +2399,33 @@ error_kmem: static int pfm_bad_permissions(struct task_struct *task) { + const struct cred *tcred; uid_t uid = current_uid(); gid_t gid = current_gid(); + int ret; + + rcu_read_lock(); + tcred = __task_cred(task); /* inspired by ptrace_attach() */ DPRINT(("cur: uid=%d gid=%d task: euid=%d suid=%d uid=%d egid=%d sgid=%d\n", uid, gid, - task->euid, - task->suid, - task->uid, - task->egid, - task->sgid)); - - return (uid != task->euid) - || (uid != task->suid) - || (uid != task->uid) - || (gid != task->egid) - || (gid != task->sgid) - || (gid != task->gid)) && !capable(CAP_SYS_PTRACE); + tcred->euid, + tcred->suid, + tcred->uid, + tcred->egid, + tcred->sgid)); + + ret = ((uid != tcred->euid) + || (uid != tcred->suid) + || (uid != tcred->uid) + || (gid != tcred->egid) + || (gid != tcred->sgid) + || (gid != tcred->gid)) && !capable(CAP_SYS_PTRACE); + + rcu_read_unlock(); + return ret; } static int diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c index 354c1ff17159..c5afc98e2675 100644 --- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -106,6 +106,7 @@ void proc_id_connector(struct task_struct *task, int which_id) struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE]; struct timespec ts; + const struct cred *cred; if (atomic_read(&proc_event_num_listeners) < 1) return; @@ -115,14 +116,19 @@ void proc_id_connector(struct task_struct *task, int which_id) ev->what = which_id; ev->event_data.id.process_pid = task->pid; ev->event_data.id.process_tgid = task->tgid; + rcu_read_lock(); + cred = __task_cred(task); if (which_id == PROC_EVENT_UID) { - ev->event_data.id.r.ruid = task->cred->uid; - ev->event_data.id.e.euid = task->cred->euid; + ev->event_data.id.r.ruid = cred->uid; + ev->event_data.id.e.euid = cred->euid; } else if (which_id == PROC_EVENT_GID) { - ev->event_data.id.r.rgid = task->cred->gid; - ev->event_data.id.e.egid = task->cred->egid; - } else + ev->event_data.id.r.rgid = cred->gid; + ev->event_data.id.e.egid = cred->egid; + } else { + rcu_read_unlock(); return; + } + rcu_read_unlock(); get_seq(&msg->seq, &ev->cpu); ktime_get_ts(&ts); /* get high res monotonic timestamp */ put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 0e6655613169..9142ff5dc8e6 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1361,6 +1361,7 @@ static void fill_prstatus(struct elf_prstatus *prstatus, static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, struct mm_struct *mm) { + const struct cred *cred; unsigned int i, len; /* first copy the parameters from user space */ @@ -1388,8 +1389,11 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, psinfo->pr_zomb = psinfo->pr_sname == 'Z'; psinfo->pr_nice = task_nice(p); psinfo->pr_flag = p->flags; - SET_UID(psinfo->pr_uid, p->cred->uid); - SET_GID(psinfo->pr_gid, p->cred->gid); + rcu_read_lock(); + cred = __task_cred(p); + SET_UID(psinfo->pr_uid, cred->uid); + SET_GID(psinfo->pr_gid, cred->gid); + rcu_read_unlock(); strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); return 0; diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 1f6e8c023b4c..45dabd59936f 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -1414,6 +1414,7 @@ static void fill_prstatus(struct elf_prstatus *prstatus, static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, struct mm_struct *mm) { + const struct cred *cred; unsigned int i, len; /* first copy the parameters from user space */ @@ -1441,8 +1442,11 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, psinfo->pr_zomb = psinfo->pr_sname == 'Z'; psinfo->pr_nice = task_nice(p); psinfo->pr_flag = p->flags; - SET_UID(psinfo->pr_uid, p->cred->uid); - SET_GID(psinfo->pr_gid, p->cred->gid); + rcu_read_lock(); + cred = __task_cred(p); + SET_UID(psinfo->pr_uid, cred->uid); + SET_GID(psinfo->pr_gid, cred->gid); + rcu_read_unlock(); strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); return 0; diff --git a/fs/fcntl.c b/fs/fcntl.c index c594cc0e40fb..87c39f1f0817 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -401,10 +401,17 @@ static const long band_table[NSIGPOLL] = { static inline int sigio_perm(struct task_struct *p, struct fown_struct *fown, int sig) { - return (((fown->euid == 0) || - (fown->euid == p->cred->suid) || (fown->euid == p->cred->uid) || - (fown->uid == p->cred->suid) || (fown->uid == p->cred->uid)) && - !security_file_send_sigiotask(p, fown, sig)); + const struct cred *cred; + int ret; + + rcu_read_lock(); + cred = __task_cred(p); + ret = ((fown->euid == 0 || + fown->euid == cred->suid || fown->euid == cred->uid || + fown->uid == cred->suid || fown->uid == cred->uid) && + !security_file_send_sigiotask(p, fown, sig)); + rcu_read_unlock(); + return ret; } static void send_sigio_to_task(struct task_struct *p, diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index e97a98981862..95bc22bdd060 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -869,18 +869,25 @@ int fuse_update_attributes(struct inode *inode, struct kstat *stat, */ int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task) { + const struct cred *cred; + int ret; + if (fc->flags & FUSE_ALLOW_OTHER) return 1; - if (task->cred->euid == fc->user_id && - task->cred->suid == fc->user_id && - task->cred->uid == fc->user_id && - task->cred->egid == fc->group_id && - task->cred->sgid == fc->group_id && - task->cred->gid == fc->group_id) - return 1; + rcu_read_lock(); + ret = 0; + cred = __task_cred(task); + if (cred->euid == fc->user_id && + cred->suid == fc->user_id && + cred->uid == fc->user_id && + cred->egid == fc->group_id && + cred->sgid == fc->group_id && + cred->gid == fc->group_id) + ret = 1; + rcu_read_unlock(); - return 0; + return ret; } static int fuse_access(struct inode *inode, int mask) diff --git a/fs/ioprio.c b/fs/ioprio.c index 5112554fd210..3569e0ad86a2 100644 --- a/fs/ioprio.c +++ b/fs/ioprio.c @@ -31,10 +31,16 @@ static int set_task_ioprio(struct task_struct *task, int ioprio) { int err; struct io_context *ioc; + const struct cred *cred = current_cred(), *tcred; - if (task->cred->uid != current_euid() && - task->cred->uid != current_uid() && !capable(CAP_SYS_NICE)) + rcu_read_lock(); + tcred = __task_cred(task); + if (tcred->uid != cred->euid && + tcred->uid != cred->uid && !capable(CAP_SYS_NICE)) { + rcu_read_unlock(); return -EPERM; + } + rcu_read_unlock(); err = security_task_setioprio(task, ioprio); if (err) @@ -131,7 +137,7 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio) break; do_each_thread(g, p) { - if (p->cred->uid != who) + if (__task_cred(p)->uid != who) continue; ret = set_task_ioprio(p, ioprio); if (ret) @@ -224,7 +230,7 @@ asmlinkage long sys_ioprio_get(int which, int who) break; do_each_thread(g, p) { - if (p->cred->uid != user->uid) + if (__task_cred(p)->uid != user->uid) continue; tmpio = get_task_ioprio(p); if (tmpio < 0) diff --git a/fs/proc/array.c b/fs/proc/array.c index 62fe9b2009b6..7e4877d9dcb5 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -159,6 +159,7 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, struct group_info *group_info; int g; struct fdtable *fdt = NULL; + const struct cred *cred; pid_t ppid, tpid; rcu_read_lock(); @@ -170,6 +171,7 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, if (tracer) tpid = task_pid_nr_ns(tracer, ns); } + cred = get_cred((struct cred *) __task_cred(p)); seq_printf(m, "State:\t%s\n" "Tgid:\t%d\n" @@ -182,8 +184,8 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, task_tgid_nr_ns(p, ns), pid_nr_ns(pid, ns), ppid, tpid, - p->cred->uid, p->cred->euid, p->cred->suid, p->cred->fsuid, - p->cred->gid, p->cred->egid, p->cred->sgid, p->cred->fsgid); + cred->uid, cred->euid, cred->suid, cred->fsuid, + cred->gid, cred->egid, cred->sgid, cred->fsgid); task_lock(p); if (p->files) @@ -194,13 +196,12 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, fdt ? fdt->max_fds : 0); rcu_read_unlock(); - group_info = p->cred->group_info; - get_group_info(group_info); + group_info = cred->group_info; task_unlock(p); for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++) seq_printf(m, "%d ", GROUP_AT(group_info, g)); - put_group_info(group_info); + put_cred(cred); seq_printf(m, "\n"); } @@ -262,7 +263,7 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p) blocked = p->blocked; collect_sigign_sigcatch(p, &ignored, &caught); num_threads = atomic_read(&p->signal->count); - qsize = atomic_read(&p->cred->user->sigpending); + qsize = atomic_read(&__task_cred(p)->user->sigpending); qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur; unlock_task_sighand(p, &flags); } @@ -293,12 +294,21 @@ static void render_cap_t(struct seq_file *m, const char *header, static inline void task_cap(struct seq_file *m, struct task_struct *p) { - struct cred *cred = p->cred; + const struct cred *cred; + kernel_cap_t cap_inheritable, cap_permitted, cap_effective, cap_bset; - render_cap_t(m, "CapInh:\t", &cred->cap_inheritable); - render_cap_t(m, "CapPrm:\t", &cred->cap_permitted); - render_cap_t(m, "CapEff:\t", &cred->cap_effective); - render_cap_t(m, "CapBnd:\t", &cred->cap_bset); + rcu_read_lock(); + cred = __task_cred(p); + cap_inheritable = cred->cap_inheritable; + cap_permitted = cred->cap_permitted; + cap_effective = cred->cap_effective; + cap_bset = cred->cap_bset; + rcu_read_unlock(); + + render_cap_t(m, "CapInh:\t", &cap_inheritable); + render_cap_t(m, "CapPrm:\t", &cap_permitted); + render_cap_t(m, "CapEff:\t", &cap_effective); + render_cap_t(m, "CapBnd:\t", &cap_bset); } static inline void task_context_switch_counts(struct seq_file *m, diff --git a/fs/proc/base.c b/fs/proc/base.c index 6862b360c36c..cf42c42cbfbb 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1406,6 +1406,7 @@ static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_st { struct inode * inode; struct proc_inode *ei; + const struct cred *cred; /* We need a new inode */ @@ -1428,8 +1429,11 @@ static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_st inode->i_uid = 0; inode->i_gid = 0; if (task_dumpable(task)) { - inode->i_uid = task->cred->euid; - inode->i_gid = task->cred->egid; + rcu_read_lock(); + cred = __task_cred(task); + inode->i_uid = cred->euid; + inode->i_gid = cred->egid; + rcu_read_unlock(); } security_task_to_inode(task, inode); @@ -1445,6 +1449,8 @@ static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat { struct inode *inode = dentry->d_inode; struct task_struct *task; + const struct cred *cred; + generic_fillattr(inode, stat); rcu_read_lock(); @@ -1454,8 +1460,9 @@ static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat if (task) { if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || task_dumpable(task)) { - stat->uid = task->cred->euid; - stat->gid = task->cred->egid; + cred = __task_cred(task); + stat->uid = cred->euid; + stat->gid = cred->egid; } } rcu_read_unlock(); @@ -1483,11 +1490,16 @@ static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; struct task_struct *task = get_proc_task(inode); + const struct cred *cred; + if (task) { if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || task_dumpable(task)) { - inode->i_uid = task->cred->euid; - inode->i_gid = task->cred->egid; + rcu_read_lock(); + cred = __task_cred(task); + inode->i_uid = cred->euid; + inode->i_gid = cred->egid; + rcu_read_unlock(); } else { inode->i_uid = 0; inode->i_gid = 0; @@ -1649,6 +1661,7 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) struct task_struct *task = get_proc_task(inode); int fd = proc_fd(inode); struct files_struct *files; + const struct cred *cred; if (task) { files = get_files_struct(task); @@ -1658,8 +1671,11 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) rcu_read_unlock(); put_files_struct(files); if (task_dumpable(task)) { - inode->i_uid = task->cred->euid; - inode->i_gid = task->cred->egid; + rcu_read_lock(); + cred = __task_cred(task); + inode->i_uid = cred->euid; + inode->i_gid = cred->egid; + rcu_read_unlock(); } else { inode->i_uid = 0; inode->i_gid = 0; diff --git a/include/linux/cred.h b/include/linux/cred.h index 4221ec6000c1..166ce4ddba64 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -147,8 +147,9 @@ static inline struct cred *get_cred(struct cred *cred) * Release a reference to a set of credentials, deleting them when the last ref * is released. */ -static inline void put_cred(struct cred *cred) +static inline void put_cred(const struct cred *_cred) { + struct cred *cred = (struct cred *) _cred; if (atomic_dec_and_test(&(cred)->usage)) __put_cred(cred); } diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 2febf5165fad..ae8ef88ade3f 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -447,7 +447,7 @@ static int audit_filter_rules(struct task_struct *tsk, struct audit_names *name, enum audit_state *state) { - struct cred *cred = tsk->cred; + const struct cred *cred = get_task_cred(tsk); int i, j, need_sid = 1; u32 sid; @@ -642,8 +642,10 @@ static int audit_filter_rules(struct task_struct *tsk, break; } - if (!result) + if (!result) { + put_cred(cred); return 0; + } } if (rule->filterkey && ctx) ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC); @@ -651,6 +653,7 @@ static int audit_filter_rules(struct task_struct *tsk, case AUDIT_NEVER: *state = AUDIT_DISABLED; break; case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; } + put_cred(cred); return 1; } @@ -1229,7 +1232,7 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) static void audit_log_exit(struct audit_context *context, struct task_struct *tsk) { - struct cred *cred = tsk->cred; + const struct cred *cred; int i, call_panic = 0; struct audit_buffer *ab; struct audit_aux_data *aux; @@ -1239,13 +1242,14 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts context->pid = tsk->pid; if (!context->ppid) context->ppid = sys_getppid(); - context->uid = cred->uid; - context->gid = cred->gid; - context->euid = cred->euid; - context->suid = cred->suid; + cred = current_cred(); + context->uid = cred->uid; + context->gid = cred->gid; + context->euid = cred->euid; + context->suid = cred->suid; context->fsuid = cred->fsuid; - context->egid = cred->egid; - context->sgid = cred->sgid; + context->egid = cred->egid; + context->sgid = cred->sgid; context->fsgid = cred->fsgid; context->personality = tsk->personality; @@ -2088,7 +2092,7 @@ int audit_set_loginuid(struct task_struct *task, uid_t loginuid) audit_log_format(ab, "login pid=%d uid=%u " "old auid=%u new auid=%u" " old ses=%u new ses=%u", - task->pid, task->cred->uid, + task->pid, task_uid(task), task->loginuid, loginuid, task->sessionid, sessionid); audit_log_end(ab); @@ -2471,7 +2475,7 @@ void __audit_ptrace(struct task_struct *t) context->target_pid = t->pid; context->target_auid = audit_get_loginuid(t); - context->target_uid = t->cred->uid; + context->target_uid = task_uid(t); context->target_sessionid = audit_get_sessionid(t); security_task_getsecid(t, &context->target_sid); memcpy(context->target_comm, t->comm, TASK_COMM_LEN); @@ -2490,6 +2494,7 @@ int __audit_signal_info(int sig, struct task_struct *t) struct audit_aux_data_pids *axp; struct task_struct *tsk = current; struct audit_context *ctx = tsk->audit_context; + uid_t uid = current_uid(), t_uid = task_uid(t); if (audit_pid && t->tgid == audit_pid) { if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) { @@ -2497,7 +2502,7 @@ int __audit_signal_info(int sig, struct task_struct *t) if (tsk->loginuid != -1) audit_sig_uid = tsk->loginuid; else - audit_sig_uid = tsk->cred->uid; + audit_sig_uid = uid; security_task_getsecid(tsk, &audit_sig_sid); } if (!audit_signals || audit_dummy_context()) @@ -2509,7 +2514,7 @@ int __audit_signal_info(int sig, struct task_struct *t) if (!ctx->target_pid) { ctx->target_pid = t->tgid; ctx->target_auid = audit_get_loginuid(t); - ctx->target_uid = t->cred->uid; + ctx->target_uid = t_uid; ctx->target_sessionid = audit_get_sessionid(t); security_task_getsecid(t, &ctx->target_sid); memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN); @@ -2530,7 +2535,7 @@ int __audit_signal_info(int sig, struct task_struct *t) axp->target_pid[axp->pid_count] = t->tgid; axp->target_auid[axp->pid_count] = audit_get_loginuid(t); - axp->target_uid[axp->pid_count] = t->cred->uid; + axp->target_uid[axp->pid_count] = t_uid; axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t); security_task_getsecid(t, &axp->target_sid[axp->pid_count]); memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index e210526e6401..a512a75a5560 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1279,7 +1279,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) static int attach_task_by_pid(struct cgroup *cgrp, u64 pid) { struct task_struct *tsk; - uid_t euid; + const struct cred *cred = current_cred(), *tcred; int ret; if (pid) { @@ -1289,16 +1289,16 @@ static int attach_task_by_pid(struct cgroup *cgrp, u64 pid) rcu_read_unlock(); return -ESRCH; } - get_task_struct(tsk); - rcu_read_unlock(); - euid = current_euid(); - if (euid && - euid != tsk->cred->uid && - euid != tsk->cred->suid) { - put_task_struct(tsk); + tcred = __task_cred(tsk); + if (cred->euid && + cred->euid != tcred->uid && + cred->euid != tcred->suid) { + rcu_read_unlock(); return -EACCES; } + get_task_struct(tsk); + rcu_read_unlock(); } else { tsk = current; get_task_struct(tsk); diff --git a/kernel/exit.c b/kernel/exit.c index e0f6e1892fb9..bbc22530f2c1 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -160,7 +160,10 @@ void release_task(struct task_struct * p) int zap_leader; repeat: tracehook_prepare_release_task(p); - atomic_dec(&p->cred->user->processes); + /* don't need to get the RCU readlock here - the process is dead and + * can't be modifying its own credentials */ + atomic_dec(&__task_cred(p)->user->processes); + proc_flush_task(p); write_lock_irq(&tasklist_lock); tracehook_finish_release_task(p); @@ -1267,12 +1270,12 @@ static int wait_task_zombie(struct task_struct *p, int options, unsigned long state; int retval, status, traced; pid_t pid = task_pid_vnr(p); + uid_t uid = __task_cred(p)->uid; if (!likely(options & WEXITED)) return 0; if (unlikely(options & WNOWAIT)) { - uid_t uid = p->cred->uid; int exit_code = p->exit_code; int why, status; @@ -1393,7 +1396,7 @@ static int wait_task_zombie(struct task_struct *p, int options, if (!retval && infop) retval = put_user(pid, &infop->si_pid); if (!retval && infop) - retval = put_user(p->cred->uid, &infop->si_uid); + retval = put_user(uid, &infop->si_uid); if (!retval) retval = pid; @@ -1458,7 +1461,8 @@ static int wait_task_stopped(int ptrace, struct task_struct *p, if (!unlikely(options & WNOWAIT)) p->exit_code = 0; - uid = p->cred->uid; + /* don't need the RCU readlock here as we're holding a spinlock */ + uid = __task_cred(p)->uid; unlock_sig: spin_unlock_irq(&p->sighand->siglock); if (!exit_code) @@ -1532,10 +1536,10 @@ static int wait_task_continued(struct task_struct *p, int options, } if (!unlikely(options & WNOWAIT)) p->signal->flags &= ~SIGNAL_STOP_CONTINUED; + uid = __task_cred(p)->uid; spin_unlock_irq(&p->sighand->siglock); pid = task_pid_vnr(p); - uid = p->cred->uid; get_task_struct(p); read_unlock(&tasklist_lock); diff --git a/kernel/futex.c b/kernel/futex.c index 28421d8210b8..4fe790e89d0f 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -439,15 +439,20 @@ static void free_pi_state(struct futex_pi_state *pi_state) static struct task_struct * futex_find_get_task(pid_t pid) { struct task_struct *p; - uid_t euid = current_euid(); + const struct cred *cred = current_cred(), *pcred; rcu_read_lock(); p = find_task_by_vpid(pid); - if (!p || (euid != p->cred->euid && - euid != p->cred->uid)) + if (!p) { p = ERR_PTR(-ESRCH); - else - get_task_struct(p); + } else { + pcred = __task_cred(p); + if (cred->euid != pcred->euid && + cred->euid != pcred->uid) + p = ERR_PTR(-ESRCH); + else + get_task_struct(p); + } rcu_read_unlock(); @@ -1831,7 +1836,7 @@ sys_get_robust_list(int pid, struct robust_list_head __user * __user *head_ptr, { struct robust_list_head __user *head; unsigned long ret; - uid_t euid = current_euid(); + const struct cred *cred = current_cred(), *pcred; if (!futex_cmpxchg_enabled) return -ENOSYS; @@ -1847,8 +1852,9 @@ sys_get_robust_list(int pid, struct robust_list_head __user * __user *head_ptr, if (!p) goto err_unlock; ret = -EPERM; - if (euid != p->cred->euid && - euid != p->cred->uid && + pcred = __task_cred(p); + if (cred->euid != pcred->euid && + cred->euid != pcred->uid && !capable(CAP_SYS_PTRACE)) goto err_unlock; head = p->robust_list; diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c index 2c3fd5ed34f5..d607a5b9ee29 100644 --- a/kernel/futex_compat.c +++ b/kernel/futex_compat.c @@ -135,7 +135,7 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, { struct compat_robust_list_head __user *head; unsigned long ret; - uid_t euid = current_euid(); + const struct cred *cred = current_cred(), *pcred; if (!futex_cmpxchg_enabled) return -ENOSYS; @@ -151,8 +151,9 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, if (!p) goto err_unlock; ret = -EPERM; - if (euid != p->cred->euid && - euid != p->cred->uid && + pcred = __task_cred(p); + if (cred->euid != pcred->euid && + cred->euid != pcred->uid && !capable(CAP_SYS_PTRACE)) goto err_unlock; head = p->compat_robust_list; diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 49849d12dd12..b9d5f4e4f6a4 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -115,7 +115,7 @@ int ptrace_check_attach(struct task_struct *child, int kill) int __ptrace_may_access(struct task_struct *task, unsigned int mode) { - struct cred *cred = current->cred, *tcred = task->cred; + const struct cred *cred = current_cred(), *tcred; /* May we inspect the given task? * This check is used both for attaching with ptrace @@ -125,19 +125,23 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode) * because setting up the necessary parent/child relationship * or halting the specified task is impossible. */ - uid_t uid = cred->uid; - gid_t gid = cred->gid; int dumpable = 0; /* Don't let security modules deny introspection */ if (task == current) return 0; - if ((uid != tcred->euid || - uid != tcred->suid || - uid != tcred->uid || - gid != tcred->egid || - gid != tcred->sgid || - gid != tcred->gid) && !capable(CAP_SYS_PTRACE)) + rcu_read_lock(); + tcred = __task_cred(task); + if ((cred->uid != tcred->euid || + cred->uid != tcred->suid || + cred->uid != tcred->uid || + cred->gid != tcred->egid || + cred->gid != tcred->sgid || + cred->gid != tcred->gid) && + !capable(CAP_SYS_PTRACE)) { + rcu_read_unlock(); return -EPERM; + } + rcu_read_unlock(); smp_rmb(); if (task->mm) dumpable = get_dumpable(task->mm); diff --git a/kernel/sched.c b/kernel/sched.c index 733c59e645aa..92992e287b10 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -345,7 +345,9 @@ static inline struct task_group *task_group(struct task_struct *p) struct task_group *tg; #ifdef CONFIG_USER_SCHED - tg = p->cred->user->tg; + rcu_read_lock(); + tg = __task_cred(p)->user->tg; + rcu_read_unlock(); #elif defined(CONFIG_CGROUP_SCHED) tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), struct task_group, css); @@ -5121,6 +5123,22 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) set_load_weight(p); } +/* + * check the target process has a UID that matches the current process's + */ +static bool check_same_owner(struct task_struct *p) +{ + const struct cred *cred = current_cred(), *pcred; + bool match; + + rcu_read_lock(); + pcred = __task_cred(p); + match = (cred->euid == pcred->euid || + cred->euid == pcred->uid); + rcu_read_unlock(); + return match; +} + static int __sched_setscheduler(struct task_struct *p, int policy, struct sched_param *param, bool user) { @@ -5128,7 +5146,6 @@ static int __sched_setscheduler(struct task_struct *p, int policy, unsigned long flags; const struct sched_class *prev_class = p->sched_class; struct rq *rq; - uid_t euid; /* may grab non-irq protected spin_locks */ BUG_ON(in_interrupt()); @@ -5181,9 +5198,7 @@ recheck: return -EPERM; /* can't change other user's priorities */ - euid = current_euid(); - if (euid != p->cred->euid && - euid != p->cred->uid) + if (!check_same_owner(p)) return -EPERM; } @@ -5394,7 +5409,6 @@ long sched_setaffinity(pid_t pid, const cpumask_t *in_mask) cpumask_t cpus_allowed; cpumask_t new_mask = *in_mask; struct task_struct *p; - uid_t euid; int retval; get_online_cpus(); @@ -5415,11 +5429,8 @@ long sched_setaffinity(pid_t pid, const cpumask_t *in_mask) get_task_struct(p); read_unlock(&tasklist_lock); - euid = current_euid(); retval = -EPERM; - if (euid != p->cred->euid && - euid != p->cred->uid && - !capable(CAP_SYS_NICE)) + if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) goto out_unlock; retval = security_task_setscheduler(p, 0, NULL); diff --git a/kernel/signal.c b/kernel/signal.c index 80e8a6489f97..84989124bafb 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -177,6 +177,11 @@ int next_signal(struct sigpending *pending, sigset_t *mask) return sig; } +/* + * allocate a new signal queue record + * - this may be called without locks if and only if t == current, otherwise an + * appopriate lock must be held to protect t's user_struct + */ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, int override_rlimit) { @@ -184,11 +189,12 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, struct user_struct *user; /* - * In order to avoid problems with "switch_user()", we want to make - * sure that the compiler doesn't re-load "t->user" + * We won't get problems with the target's UID changing under us + * because changing it requires RCU be used, and if t != current, the + * caller must be holding the RCU readlock (by way of a spinlock) and + * we use RCU protection here */ - user = t->cred->user; - barrier(); + user = __task_cred(t)->user; atomic_inc(&user->sigpending); if (override_rlimit || atomic_read(&user->sigpending) <= @@ -562,12 +568,13 @@ static int rm_from_queue(unsigned long mask, struct sigpending *s) /* * Bad permissions for sending the signal + * - the caller must hold at least the RCU read lock */ static int check_kill_permission(int sig, struct siginfo *info, struct task_struct *t) { + const struct cred *cred = current_cred(), *tcred; struct pid *sid; - uid_t uid, euid; int error; if (!valid_signal(sig)) @@ -580,10 +587,11 @@ static int check_kill_permission(int sig, struct siginfo *info, if (error) return error; - uid = current_uid(); - euid = current_euid(); - if ((euid ^ t->cred->suid) && (euid ^ t->cred->uid) && - (uid ^ t->cred->suid) && (uid ^ t->cred->uid) && + tcred = __task_cred(t); + if ((cred->euid ^ tcred->suid) && + (cred->euid ^ tcred->uid) && + (cred->uid ^ tcred->suid) && + (cred->uid ^ tcred->uid) && !capable(CAP_KILL)) { switch (sig) { case SIGCONT: @@ -1011,6 +1019,10 @@ struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long return sighand; } +/* + * send signal info to all the members of a group + * - the caller must hold the RCU read lock at least + */ int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) { unsigned long flags; @@ -1032,8 +1044,8 @@ int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) /* * __kill_pgrp_info() sends a signal to a process group: this is what the tty * control characters do (^C, ^Z etc) + * - the caller must hold at least a readlock on tasklist_lock */ - int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) { struct task_struct *p = NULL; @@ -1089,6 +1101,7 @@ int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, { int ret = -EINVAL; struct task_struct *p; + const struct cred *pcred; if (!valid_signal(sig)) return ret; @@ -1099,9 +1112,11 @@ int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, ret = -ESRCH; goto out_unlock; } - if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info))) - && (euid != p->cred->suid) && (euid != p->cred->uid) - && (uid != p->cred->suid) && (uid != p->cred->uid)) { + pcred = __task_cred(p); + if ((info == SEND_SIG_NOINFO || + (!is_si_special(info) && SI_FROMUSER(info))) && + euid != pcred->suid && euid != pcred->uid && + uid != pcred->suid && uid != pcred->uid) { ret = -EPERM; goto out_unlock; } @@ -1372,10 +1387,9 @@ int do_notify_parent(struct task_struct *tsk, int sig) */ rcu_read_lock(); info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); + info.si_uid = __task_cred(tsk)->uid; rcu_read_unlock(); - info.si_uid = tsk->cred->uid; - thread_group_cputime(tsk, &cputime); info.si_utime = cputime_to_jiffies(cputime.utime); info.si_stime = cputime_to_jiffies(cputime.stime); @@ -1443,10 +1457,9 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, int why) */ rcu_read_lock(); info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); + info.si_uid = __task_cred(tsk)->uid; rcu_read_unlock(); - info.si_uid = tsk->cred->uid; - info.si_utime = cputime_to_clock_t(tsk->utime); info.si_stime = cputime_to_clock_t(tsk->stime); @@ -1713,7 +1726,7 @@ static int ptrace_signal(int signr, siginfo_t *info, info->si_errno = 0; info->si_code = SI_USER; info->si_pid = task_pid_vnr(current->parent); - info->si_uid = current->parent->cred->uid; + info->si_uid = task_uid(current->parent); } /* If the (new) signal is now blocked, requeue it. */ diff --git a/kernel/sys.c b/kernel/sys.c index c4d6b59553e9..ccc9eb736d35 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -112,14 +112,17 @@ EXPORT_SYMBOL(cad_pid); void (*pm_power_off_prepare)(void); +/* + * set the priority of a task + * - the caller must hold the RCU read lock + */ static int set_one_prio(struct task_struct *p, int niceval, int error) { - uid_t euid = current_euid(); + const struct cred *cred = current_cred(), *pcred = __task_cred(p); int no_nice; - if (p->cred->uid != euid && - p->cred->euid != euid && - !capable(CAP_SYS_NICE)) { + if (pcred->uid != cred->euid && + pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) { error = -EPERM; goto out; } diff --git a/kernel/tsacct.c b/kernel/tsacct.c index 6d1ed07bf312..2dc06ab35716 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -27,6 +27,7 @@ */ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk) { + const struct cred *tcred; struct timespec uptime, ts; u64 ac_etime; @@ -53,10 +54,11 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk) stats->ac_flag |= AXSIG; stats->ac_nice = task_nice(tsk); stats->ac_sched = tsk->policy; - stats->ac_uid = tsk->cred->uid; - stats->ac_gid = tsk->cred->gid; stats->ac_pid = tsk->pid; rcu_read_lock(); + tcred = __task_cred(tsk); + stats->ac_uid = tcred->uid; + stats->ac_gid = tcred->gid; stats->ac_ppid = pid_alive(tsk) ? rcu_dereference(tsk->real_parent)->tgid : 0; rcu_read_unlock(); diff --git a/mm/mempolicy.c b/mm/mempolicy.c index b23492ee3e50..7555219c535b 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1110,7 +1110,7 @@ asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode, const unsigned long __user *old_nodes, const unsigned long __user *new_nodes) { - struct cred *cred, *tcred; + const struct cred *cred = current_cred(), *tcred; struct mm_struct *mm; struct task_struct *task; nodemask_t old; @@ -1145,14 +1145,16 @@ asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode, * capabilities, superuser privileges or the same * userid as the target process. */ - cred = current->cred; - tcred = task->cred; + rcu_read_lock(); + tcred = __task_cred(task); if (cred->euid != tcred->suid && cred->euid != tcred->uid && cred->uid != tcred->suid && cred->uid != tcred->uid && !capable(CAP_SYS_NICE)) { + rcu_read_unlock(); err = -EPERM; goto out; } + rcu_read_unlock(); task_nodes = cpuset_mems_allowed(task); /* Is the user allowed to access the target nodes? */ diff --git a/mm/migrate.c b/mm/migrate.c index 794443da1b4f..142284229ce2 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1045,7 +1045,7 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages, const int __user *nodes, int __user *status, int flags) { - struct cred *cred, *tcred; + const struct cred *cred = current_cred(), *tcred; struct task_struct *task; struct mm_struct *mm; int err; @@ -1076,14 +1076,16 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages, * capabilities, superuser privileges or the same * userid as the target process. */ - cred = current->cred; - tcred = task->cred; + rcu_read_lock(); + tcred = __task_cred(task); if (cred->euid != tcred->suid && cred->euid != tcred->uid && cred->uid != tcred->suid && cred->uid != tcred->uid && !capable(CAP_SYS_NICE)) { + rcu_read_unlock(); err = -EPERM; goto out; } + rcu_read_unlock(); err = security_task_movememory(task); if (err) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 3af787ba2077..0e0b282a2073 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -298,9 +298,9 @@ static void dump_tasks(const struct mem_cgroup *mem) task_lock(p); printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d %3d %s\n", - p->pid, p->cred->uid, p->tgid, p->mm->total_vm, - get_mm_rss(p->mm), (int)task_cpu(p), p->oomkilladj, - p->comm); + p->pid, __task_cred(p)->uid, p->tgid, + p->mm->total_vm, get_mm_rss(p->mm), (int)task_cpu(p), + p->oomkilladj, p->comm); task_unlock(p); } while_each_thread(g, p); } diff --git a/security/commoncap.c b/security/commoncap.c index 61307f590003..0384bf95db68 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -51,10 +51,13 @@ EXPORT_SYMBOL(cap_netlink_recv); */ int cap_capable(struct task_struct *tsk, int cap, int audit) { + __u32 cap_raised; + /* Derived from include/linux/sched.h:capable. */ - if (cap_raised(tsk->cred->cap_effective, cap)) - return 0; - return -EPERM; + rcu_read_lock(); + cap_raised = cap_raised(__task_cred(tsk)->cap_effective, cap); + rcu_read_unlock(); + return cap_raised ? 0 : -EPERM; } int cap_settime(struct timespec *ts, struct timezone *tz) @@ -66,34 +69,42 @@ int cap_settime(struct timespec *ts, struct timezone *tz) int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) { - /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ - if (cap_issubset(child->cred->cap_permitted, - current->cred->cap_permitted)) - return 0; - if (capable(CAP_SYS_PTRACE)) - return 0; - return -EPERM; + int ret = 0; + + rcu_read_lock(); + if (!cap_issubset(child->cred->cap_permitted, + current->cred->cap_permitted) && + !capable(CAP_SYS_PTRACE)) + ret = -EPERM; + rcu_read_unlock(); + return ret; } int cap_ptrace_traceme(struct task_struct *parent) { - if (cap_issubset(current->cred->cap_permitted, - parent->cred->cap_permitted)) - return 0; - if (has_capability(parent, CAP_SYS_PTRACE)) - return 0; - return -EPERM; + int ret = 0; + + rcu_read_lock(); + if (!cap_issubset(current->cred->cap_permitted, + parent->cred->cap_permitted) && + !has_capability(parent, CAP_SYS_PTRACE)) + ret = -EPERM; + rcu_read_unlock(); + return ret; } int cap_capget (struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted) { - struct cred *cred = target->cred; + const struct cred *cred; /* Derived from kernel/capability.c:sys_capget. */ + rcu_read_lock(); + cred = __task_cred(target); *effective = cred->cap_effective; *inheritable = cred->cap_inheritable; *permitted = cred->cap_permitted; + rcu_read_unlock(); return 0; } @@ -433,7 +444,7 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) int cap_bprm_secureexec (struct linux_binprm *bprm) { - const struct cred *cred = current->cred; + const struct cred *cred = current_cred(); if (cred->uid != 0) { if (bprm->cap_effective) @@ -511,11 +522,11 @@ static inline void cap_emulate_setxuid (int old_ruid, int old_euid, if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) && (cred->uid != 0 && cred->euid != 0 && cred->suid != 0) && !issecure(SECURE_KEEP_CAPS)) { - cap_clear (cred->cap_permitted); - cap_clear (cred->cap_effective); + cap_clear(cred->cap_permitted); + cap_clear(cred->cap_effective); } if (old_euid == 0 && cred->euid != 0) { - cap_clear (cred->cap_effective); + cap_clear(cred->cap_effective); } if (old_euid != 0 && cred->euid == 0) { cred->cap_effective = cred->cap_permitted; @@ -582,9 +593,14 @@ int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, */ static int cap_safe_nice(struct task_struct *p) { - if (!cap_issubset(p->cred->cap_permitted, - current->cred->cap_permitted) && - !capable(CAP_SYS_NICE)) + int is_subset; + + rcu_read_lock(); + is_subset = cap_issubset(__task_cred(p)->cap_permitted, + current_cred()->cap_permitted); + rcu_read_unlock(); + + if (!is_subset && !capable(CAP_SYS_NICE)) return -EPERM; return 0; } diff --git a/security/keys/permission.c b/security/keys/permission.c index baf3d5f31e71..13c36164f284 100644 --- a/security/keys/permission.c +++ b/security/keys/permission.c @@ -22,13 +22,16 @@ int key_task_permission(const key_ref_t key_ref, struct task_struct *context, key_perm_t perm) { - struct cred *cred = context->cred; + const struct cred *cred; struct key *key; key_perm_t kperm; int ret; key = key_ref_to_ptr(key_ref); + rcu_read_lock(); + cred = __task_cred(context); + /* use the second 8-bits of permissions for keys the caller owns */ if (key->uid == cred->fsuid) { kperm = key->perm >> 16; @@ -43,10 +46,7 @@ int key_task_permission(const key_ref_t key_ref, goto use_these_perms; } - spin_lock(&cred->lock); ret = groups_search(cred->group_info, key->gid); - spin_unlock(&cred->lock); - if (ret) { kperm = key->perm >> 8; goto use_these_perms; @@ -57,6 +57,8 @@ int key_task_permission(const key_ref_t key_ref, kperm = key->perm; use_these_perms: + rcu_read_lock(); + /* use the top 8-bits of permissions for keys the caller possesses * - possessor permissions are additive with other permissions */ diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index ce8ac6073d57..212601ebaa46 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -412,10 +412,13 @@ key_ref_t search_process_keyrings(struct key_type *type, struct task_struct *context) { struct request_key_auth *rka; + struct cred *cred; key_ref_t key_ref, ret, err; might_sleep(); + cred = get_task_cred(context); + /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were * searchable, but we failed to find a key or we found a negative key; * otherwise we want to return a sample error (probably -EACCES) if @@ -428,9 +431,9 @@ key_ref_t search_process_keyrings(struct key_type *type, err = ERR_PTR(-EAGAIN); /* search the thread keyring first */ - if (context->cred->thread_keyring) { + if (cred->thread_keyring) { key_ref = keyring_search_aux( - make_key_ref(context->cred->thread_keyring, 1), + make_key_ref(cred->thread_keyring, 1), context, type, description, match); if (!IS_ERR(key_ref)) goto found; @@ -495,9 +498,9 @@ key_ref_t search_process_keyrings(struct key_type *type, } } /* or search the user-session keyring */ - else if (context->cred->user->session_keyring) { + else if (cred->user->session_keyring) { key_ref = keyring_search_aux( - make_key_ref(context->cred->user->session_keyring, 1), + make_key_ref(cred->user->session_keyring, 1), context, type, description, match); if (!IS_ERR(key_ref)) goto found; @@ -519,20 +522,20 @@ key_ref_t search_process_keyrings(struct key_type *type, * search the keyrings of the process mentioned there * - we don't permit access to request_key auth keys via this method */ - if (context->cred->request_key_auth && + if (cred->request_key_auth && context == current && type != &key_type_request_key_auth ) { /* defend against the auth key being revoked */ - down_read(&context->cred->request_key_auth->sem); + down_read(&cred->request_key_auth->sem); - if (key_validate(context->cred->request_key_auth) == 0) { - rka = context->cred->request_key_auth->payload.data; + if (key_validate(cred->request_key_auth) == 0) { + rka = cred->request_key_auth->payload.data; key_ref = search_process_keyrings(type, description, match, rka->context); - up_read(&context->cred->request_key_auth->sem); + up_read(&cred->request_key_auth->sem); if (!IS_ERR(key_ref)) goto found; @@ -549,7 +552,7 @@ key_ref_t search_process_keyrings(struct key_type *type, break; } } else { - up_read(&context->cred->request_key_auth->sem); + up_read(&cred->request_key_auth->sem); } } @@ -557,6 +560,7 @@ key_ref_t search_process_keyrings(struct key_type *type, key_ref = ret ? ret : err; found: + put_cred(cred); return key_ref; } /* end search_process_keyrings() */ diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 10715d1330b9..c86303638235 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -95,13 +95,18 @@ extern void selnl_notify_setenforce(int val); static int task_has_security(struct task_struct *tsk, u32 perms) { - struct task_security_struct *tsec; - - tsec = tsk->cred->security; + const struct task_security_struct *tsec; + u32 sid = 0; + + rcu_read_lock(); + tsec = __task_cred(tsk)->security; + if (tsec) + sid = tsec->sid; + rcu_read_unlock(); if (!tsec) return -EACCES; - return avc_has_perm(tsec->sid, SECINITSID_SECURITY, + return avc_has_perm(sid, SECINITSID_SECURITY, SECCLASS_SECURITY, perms, NULL); } diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index e8a4fcb1ad04..11167fd567b9 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -30,6 +30,8 @@ #include "smack.h" +#define task_security(task) (task_cred_xxx((task), security)) + /* * I hope these are the hokeyist lines of code in the module. Casey. */ @@ -1012,7 +1014,7 @@ static void smack_cred_free(struct cred *cred) */ static int smack_task_setpgid(struct task_struct *p, pid_t pgid) { - return smk_curacc(p->cred->security, MAY_WRITE); + return smk_curacc(task_security(p), MAY_WRITE); } /** @@ -1023,7 +1025,7 @@ static int smack_task_setpgid(struct task_struct *p, pid_t pgid) */ static int smack_task_getpgid(struct task_struct *p) { - return smk_curacc(p->cred->security, MAY_READ); + return smk_curacc(task_security(p), MAY_READ); } /** @@ -1034,7 +1036,7 @@ static int smack_task_getpgid(struct task_struct *p) */ static int smack_task_getsid(struct task_struct *p) { - return smk_curacc(p->cred->security, MAY_READ); + return smk_curacc(task_security(p), MAY_READ); } /** @@ -1046,7 +1048,7 @@ static int smack_task_getsid(struct task_struct *p) */ static void smack_task_getsecid(struct task_struct *p, u32 *secid) { - *secid = smack_to_secid(p->cred->security); + *secid = smack_to_secid(task_security(p)); } /** @@ -1062,7 +1064,7 @@ static int smack_task_setnice(struct task_struct *p, int nice) rc = cap_task_setnice(p, nice); if (rc == 0) - rc = smk_curacc(p->cred->security, MAY_WRITE); + rc = smk_curacc(task_security(p), MAY_WRITE); return rc; } @@ -1079,7 +1081,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio) rc = cap_task_setioprio(p, ioprio); if (rc == 0) - rc = smk_curacc(p->cred->security, MAY_WRITE); + rc = smk_curacc(task_security(p), MAY_WRITE); return rc; } @@ -1091,7 +1093,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio) */ static int smack_task_getioprio(struct task_struct *p) { - return smk_curacc(p->cred->security, MAY_READ); + return smk_curacc(task_security(p), MAY_READ); } /** @@ -1109,7 +1111,7 @@ static int smack_task_setscheduler(struct task_struct *p, int policy, rc = cap_task_setscheduler(p, policy, lp); if (rc == 0) - rc = smk_curacc(p->cred->security, MAY_WRITE); + rc = smk_curacc(task_security(p), MAY_WRITE); return rc; } @@ -1121,7 +1123,7 @@ static int smack_task_setscheduler(struct task_struct *p, int policy, */ static int smack_task_getscheduler(struct task_struct *p) { - return smk_curacc(p->cred->security, MAY_READ); + return smk_curacc(task_security(p), MAY_READ); } /** @@ -1132,7 +1134,7 @@ static int smack_task_getscheduler(struct task_struct *p) */ static int smack_task_movememory(struct task_struct *p) { - return smk_curacc(p->cred->security, MAY_WRITE); + return smk_curacc(task_security(p), MAY_WRITE); } /** @@ -1155,13 +1157,13 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info, * can write the receiver. */ if (secid == 0) - return smk_curacc(p->cred->security, MAY_WRITE); + return smk_curacc(task_security(p), MAY_WRITE); /* * If the secid isn't 0 we're dealing with some USB IO * specific behavior. This is not clean. For one thing * we can't take privilege into account. */ - return smk_access(smack_from_secid(secid), p->cred->security, MAY_WRITE); + return smk_access(smack_from_secid(secid), task_security(p), MAY_WRITE); } /** @@ -1174,7 +1176,7 @@ static int smack_task_wait(struct task_struct *p) { int rc; - rc = smk_access(current->cred->security, p->cred->security, MAY_WRITE); + rc = smk_access(current_security(), task_security(p), MAY_WRITE); if (rc == 0) return 0; @@ -1205,7 +1207,7 @@ static int smack_task_wait(struct task_struct *p) static void smack_task_to_inode(struct task_struct *p, struct inode *inode) { struct inode_smack *isp = inode->i_security; - isp->smk_inode = p->cred->security; + isp->smk_inode = task_security(p); } /* @@ -2010,7 +2012,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value) if (strcmp(name, "current") != 0) return -EINVAL; - cp = kstrdup(p->cred->security, GFP_KERNEL); + cp = kstrdup(task_security(p), GFP_KERNEL); if (cp == NULL) return -ENOMEM; -- cgit v1.2.3 From bb952bb98a7e479262c7eb25d5592545a3af147d Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:20 +1100 Subject: CRED: Separate per-task-group keyrings from signal_struct Separate per-task-group keyrings from signal_struct and dangle their anchor from the cred struct rather than the signal_struct. Signed-off-by: David Howells Reviewed-by: James Morris Signed-off-by: James Morris --- include/linux/cred.h | 16 +++++++ include/linux/key.h | 8 +--- include/linux/sched.h | 6 --- kernel/cred.c | 63 +++++++++++++++++++++++++++ kernel/fork.c | 7 --- security/keys/process_keys.c | 100 +++++++++++++++++-------------------------- security/keys/request_key.c | 34 ++++++--------- 7 files changed, 135 insertions(+), 99 deletions(-) (limited to 'include') diff --git a/include/linux/cred.h b/include/linux/cred.h index 166ce4ddba64..62b9e532422d 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -71,6 +71,21 @@ extern int groups_search(const struct group_info *, gid_t); extern int in_group_p(gid_t); extern int in_egroup_p(gid_t); +/* + * The common credentials for a thread group + * - shared by CLONE_THREAD + */ +#ifdef CONFIG_KEYS +struct thread_group_cred { + atomic_t usage; + pid_t tgid; /* thread group process ID */ + spinlock_t lock; + struct key *session_keyring; /* keyring inherited over fork */ + struct key *process_keyring; /* keyring private to this process */ + struct rcu_head rcu; /* RCU deletion hook */ +}; +#endif + /* * The security context of a task * @@ -114,6 +129,7 @@ struct cred { * keys to */ struct key *thread_keyring; /* keyring private to this thread */ struct key *request_key_auth; /* assumed request_key authority */ + struct thread_group_cred *tgcred; /* thread-group shared credentials */ #endif #ifdef CONFIG_SECURITY void *security; /* subjective LSM security */ diff --git a/include/linux/key.h b/include/linux/key.h index df709e1af3cd..0836cc838b0c 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -278,9 +278,7 @@ extern ctl_table key_sysctls[]; */ extern void switch_uid_keyring(struct user_struct *new_user); extern int copy_keys(unsigned long clone_flags, struct task_struct *tsk); -extern int copy_thread_group_keys(struct task_struct *tsk); extern void exit_keys(struct task_struct *tsk); -extern void exit_thread_group_keys(struct signal_struct *tg); extern int suid_keys(struct task_struct *tsk); extern int exec_keys(struct task_struct *tsk); extern void key_fsuid_changed(struct task_struct *tsk); @@ -289,8 +287,8 @@ extern void key_init(void); #define __install_session_keyring(keyring) \ ({ \ - struct key *old_session = current->signal->session_keyring; \ - current->signal->session_keyring = keyring; \ + struct key *old_session = current->cred->tgcred->session_keyring; \ + current->cred->tgcred->session_keyring = keyring; \ old_session; \ }) @@ -308,9 +306,7 @@ extern void key_init(void); #define switch_uid_keyring(u) do { } while(0) #define __install_session_keyring(k) ({ NULL; }) #define copy_keys(f,t) 0 -#define copy_thread_group_keys(t) 0 #define exit_keys(t) do { } while(0) -#define exit_thread_group_keys(tg) do { } while(0) #define suid_keys(t) do { } while(0) #define exec_keys(t) do { } while(0) #define key_fsuid_changed(t) do { } while(0) diff --git a/include/linux/sched.h b/include/linux/sched.h index 740cf946c8cc..2913252989b3 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -571,12 +571,6 @@ struct signal_struct { */ struct rlimit rlim[RLIM_NLIMITS]; - /* keep the process-shared keyrings here so that they do the right - * thing in threads created with CLONE_THREAD */ -#ifdef CONFIG_KEYS - struct key *session_keyring; /* keyring inherited over fork */ - struct key *process_keyring; /* keyring private to this process */ -#endif #ifdef CONFIG_BSD_PROCESS_ACCT struct pacct_struct pacct; /* per-process accounting information */ #endif diff --git a/kernel/cred.c b/kernel/cred.c index 833244a7cb05..ac73e3617684 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -16,6 +16,17 @@ #include #include +/* + * The common credentials for the initial task's thread group + */ +#ifdef CONFIG_KEYS +static struct thread_group_cred init_tgcred = { + .usage = ATOMIC_INIT(2), + .tgid = 0, + .lock = SPIN_LOCK_UNLOCKED, +}; +#endif + /* * The initial credentials for the initial task */ @@ -28,8 +39,41 @@ struct cred init_cred = { .cap_bset = CAP_INIT_BSET, .user = INIT_USER, .group_info = &init_groups, +#ifdef CONFIG_KEYS + .tgcred = &init_tgcred, +#endif }; +/* + * Dispose of the shared task group credentials + */ +#ifdef CONFIG_KEYS +static void release_tgcred_rcu(struct rcu_head *rcu) +{ + struct thread_group_cred *tgcred = + container_of(rcu, struct thread_group_cred, rcu); + + BUG_ON(atomic_read(&tgcred->usage) != 0); + + key_put(tgcred->session_keyring); + key_put(tgcred->process_keyring); + kfree(tgcred); +} +#endif + +/* + * Release a set of thread group credentials. + */ +static void release_tgcred(struct cred *cred) +{ +#ifdef CONFIG_KEYS + struct thread_group_cred *tgcred = cred->tgcred; + + if (atomic_dec_and_test(&tgcred->usage)) + call_rcu(&tgcred->rcu, release_tgcred_rcu); +#endif +} + /* * The RCU callback to actually dispose of a set of credentials */ @@ -41,6 +85,7 @@ static void put_cred_rcu(struct rcu_head *rcu) key_put(cred->thread_keyring); key_put(cred->request_key_auth); + release_tgcred(cred); put_group_info(cred->group_info); free_uid(cred->user); security_cred_free(cred); @@ -71,12 +116,30 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) if (!pcred) return -ENOMEM; +#ifdef CONFIG_KEYS + if (clone_flags & CLONE_THREAD) { + atomic_inc(&pcred->tgcred->usage); + } else { + pcred->tgcred = kmalloc(sizeof(struct cred), GFP_KERNEL); + if (!pcred->tgcred) { + kfree(pcred); + return -ENOMEM; + } + atomic_set(&pcred->tgcred->usage, 1); + spin_lock_init(&pcred->tgcred->lock); + pcred->tgcred->process_keyring = NULL; + pcred->tgcred->session_keyring = + key_get(p->cred->tgcred->session_keyring); + } +#endif + #ifdef CONFIG_SECURITY pcred->security = NULL; #endif ret = security_cred_alloc(pcred); if (ret < 0) { + release_tgcred(pcred); kfree(pcred); return ret; } diff --git a/kernel/fork.c b/kernel/fork.c index c932e283ddfc..ded1972672a3 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -802,12 +802,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) if (!sig) return -ENOMEM; - ret = copy_thread_group_keys(tsk); - if (ret < 0) { - kmem_cache_free(signal_cachep, sig); - return ret; - } - atomic_set(&sig->count, 1); atomic_set(&sig->live, 1); init_waitqueue_head(&sig->wait_chldexit); @@ -852,7 +846,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) void __cleanup_signal(struct signal_struct *sig) { thread_group_cputime_free(sig); - exit_thread_group_keys(sig); tty_kref_put(sig->tty); kmem_cache_free(signal_cachep, sig); } diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 212601ebaa46..70ee93406f30 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -189,7 +189,7 @@ int install_process_keyring(void) might_sleep(); - if (!tsk->signal->process_keyring) { + if (!tsk->cred->tgcred->process_keyring) { sprintf(buf, "_pid.%u", tsk->tgid); keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk, @@ -200,12 +200,12 @@ int install_process_keyring(void) } /* attach keyring */ - spin_lock_irq(&tsk->sighand->siglock); - if (!tsk->signal->process_keyring) { - tsk->signal->process_keyring = keyring; + spin_lock_irq(&tsk->cred->tgcred->lock); + if (!tsk->cred->tgcred->process_keyring) { + tsk->cred->tgcred->process_keyring = keyring; keyring = NULL; } - spin_unlock_irq(&tsk->sighand->siglock); + spin_unlock_irq(&tsk->cred->tgcred->lock); key_put(keyring); } @@ -235,11 +235,11 @@ static int install_session_keyring(struct key *keyring) sprintf(buf, "_ses.%u", tsk->tgid); flags = KEY_ALLOC_QUOTA_OVERRUN; - if (tsk->signal->session_keyring) + if (tsk->cred->tgcred->session_keyring) flags = KEY_ALLOC_IN_QUOTA; - keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk, - flags, NULL); + keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, + tsk, flags, NULL); if (IS_ERR(keyring)) return PTR_ERR(keyring); } @@ -248,10 +248,10 @@ static int install_session_keyring(struct key *keyring) } /* install the keyring */ - spin_lock_irq(&tsk->sighand->siglock); - old = tsk->signal->session_keyring; - rcu_assign_pointer(tsk->signal->session_keyring, keyring); - spin_unlock_irq(&tsk->sighand->siglock); + spin_lock_irq(&tsk->cred->tgcred->lock); + old = tsk->cred->tgcred->session_keyring; + rcu_assign_pointer(tsk->cred->tgcred->session_keyring, keyring); + spin_unlock_irq(&tsk->cred->tgcred->lock); /* we're using RCU on the pointer, but there's no point synchronising * on it if it didn't previously point to anything */ @@ -264,28 +264,6 @@ static int install_session_keyring(struct key *keyring) } /* end install_session_keyring() */ -/*****************************************************************************/ -/* - * copy the keys in a thread group for fork without CLONE_THREAD - */ -int copy_thread_group_keys(struct task_struct *tsk) -{ - key_check(current->thread_group->session_keyring); - key_check(current->thread_group->process_keyring); - - /* no process keyring yet */ - tsk->signal->process_keyring = NULL; - - /* same session keyring */ - rcu_read_lock(); - tsk->signal->session_keyring = - key_get(rcu_dereference(current->signal->session_keyring)); - rcu_read_unlock(); - - return 0; - -} /* end copy_thread_group_keys() */ - /*****************************************************************************/ /* * copy the keys for fork @@ -305,17 +283,6 @@ int copy_keys(unsigned long clone_flags, struct task_struct *tsk) } /* end copy_keys() */ -/*****************************************************************************/ -/* - * dispose of thread group keys upon thread group destruction - */ -void exit_thread_group_keys(struct signal_struct *tg) -{ - key_put(tg->session_keyring); - key_put(tg->process_keyring); - -} /* end exit_thread_group_keys() */ - /*****************************************************************************/ /* * dispose of per-thread keys upon thread exit @@ -344,10 +311,10 @@ int exec_keys(struct task_struct *tsk) key_put(old); /* discard the process keyring from a newly exec'd task */ - spin_lock_irq(&tsk->sighand->siglock); - old = tsk->signal->process_keyring; - tsk->signal->process_keyring = NULL; - spin_unlock_irq(&tsk->sighand->siglock); + spin_lock_irq(&tsk->cred->tgcred->lock); + old = tsk->cred->tgcred->process_keyring; + tsk->cred->tgcred->process_keyring = NULL; + spin_unlock_irq(&tsk->cred->tgcred->lock); key_put(old); @@ -452,9 +419,9 @@ key_ref_t search_process_keyrings(struct key_type *type, } /* search the process keyring second */ - if (context->signal->process_keyring) { + if (cred->tgcred->process_keyring) { key_ref = keyring_search_aux( - make_key_ref(context->signal->process_keyring, 1), + make_key_ref(cred->tgcred->process_keyring, 1), context, type, description, match); if (!IS_ERR(key_ref)) goto found; @@ -473,11 +440,11 @@ key_ref_t search_process_keyrings(struct key_type *type, } /* search the session keyring */ - if (context->signal->session_keyring) { + if (cred->tgcred->session_keyring) { rcu_read_lock(); key_ref = keyring_search_aux( make_key_ref(rcu_dereference( - context->signal->session_keyring), + cred->tgcred->session_keyring), 1), context, type, description, match); rcu_read_unlock(); @@ -586,11 +553,13 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, { struct request_key_auth *rka; struct task_struct *t = current; - struct cred *cred = current_cred(); + struct cred *cred; struct key *key; key_ref_t key_ref, skey_ref; int ret; +try_again: + cred = get_current_cred(); key_ref = ERR_PTR(-ENOKEY); switch (id) { @@ -604,6 +573,7 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, key = ERR_PTR(ret); goto error; } + goto reget_creds; } key = cred->thread_keyring; @@ -612,7 +582,7 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, break; case KEY_SPEC_PROCESS_KEYRING: - if (!t->signal->process_keyring) { + if (!cred->tgcred->process_keyring) { if (!create) goto error; @@ -621,15 +591,16 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, key = ERR_PTR(ret); goto error; } + goto reget_creds; } - key = t->signal->process_keyring; + key = cred->tgcred->process_keyring; atomic_inc(&key->usage); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_SESSION_KEYRING: - if (!t->signal->session_keyring) { + if (!cred->tgcred->session_keyring) { /* always install a session keyring upon access if one * doesn't exist yet */ ret = install_user_keyrings(); @@ -639,10 +610,11 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, cred->user->session_keyring); if (ret < 0) goto error; + goto reget_creds; } rcu_read_lock(); - key = rcu_dereference(t->signal->session_keyring); + key = rcu_dereference(cred->tgcred->session_keyring); atomic_inc(&key->usage); rcu_read_unlock(); key_ref = make_key_ref(key, 1); @@ -758,6 +730,7 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, goto invalid_key; error: + put_cred(cred); return key_ref; invalid_key: @@ -765,6 +738,12 @@ invalid_key: key_ref = ERR_PTR(ret); goto error; + /* if we attempted to install a keyring, then it may have caused new + * creds to be installed */ +reget_creds: + put_cred(cred); + goto try_again; + } /* end lookup_user_key() */ /*****************************************************************************/ @@ -777,6 +756,7 @@ invalid_key: long join_session_keyring(const char *name) { struct task_struct *tsk = current; + struct cred *cred = current->cred; struct key *keyring; long ret; @@ -787,7 +767,7 @@ long join_session_keyring(const char *name) goto error; rcu_read_lock(); - ret = rcu_dereference(tsk->signal->session_keyring)->serial; + ret = rcu_dereference(cred->tgcred->session_keyring)->serial; rcu_read_unlock(); goto error; } @@ -799,7 +779,7 @@ long join_session_keyring(const char *name) keyring = find_keyring_by_name(name, false); if (PTR_ERR(keyring) == -ENOKEY) { /* not found - try and create a new one */ - keyring = keyring_alloc(name, tsk->cred->uid, tsk->cred->gid, tsk, + keyring = keyring_alloc(name, cred->uid, cred->gid, tsk, KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 0488b0af5bd6..3d12558362df 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -66,7 +66,6 @@ static int call_sbin_request_key(struct key_construction *cons, const char *op, void *aux) { - struct task_struct *tsk = current; const struct cred *cred = current_cred(); key_serial_t prkey, sskey; struct key *key = cons->key, *authkey = cons->authkey, *keyring; @@ -109,18 +108,13 @@ static int call_sbin_request_key(struct key_construction *cons, cred->thread_keyring->serial : 0); prkey = 0; - if (tsk->signal->process_keyring) - prkey = tsk->signal->process_keyring->serial; + if (cred->tgcred->process_keyring) + prkey = cred->tgcred->process_keyring->serial; - sprintf(keyring_str[1], "%d", prkey); - - if (tsk->signal->session_keyring) { - rcu_read_lock(); - sskey = rcu_dereference(tsk->signal->session_keyring)->serial; - rcu_read_unlock(); - } else { + if (cred->tgcred->session_keyring) + sskey = rcu_dereference(cred->tgcred->session_keyring)->serial; + else sskey = cred->user->session_keyring->serial; - } sprintf(keyring_str[2], "%d", sskey); @@ -222,7 +216,7 @@ static int construct_key(struct key *key, const void *callout_info, static void construct_get_dest_keyring(struct key **_dest_keyring) { struct request_key_auth *rka; - struct task_struct *tsk = current; + const struct cred *cred = current_cred(); struct key *dest_keyring = *_dest_keyring, *authkey; kenter("%p", dest_keyring); @@ -234,11 +228,11 @@ static void construct_get_dest_keyring(struct key **_dest_keyring) } else { /* use a default keyring; falling through the cases until we * find one that we actually have */ - switch (tsk->cred->jit_keyring) { + switch (cred->jit_keyring) { case KEY_REQKEY_DEFL_DEFAULT: case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: - if (tsk->cred->request_key_auth) { - authkey = tsk->cred->request_key_auth; + if (cred->request_key_auth) { + authkey = cred->request_key_auth; down_read(&authkey->sem); rka = authkey->payload.data; if (!test_bit(KEY_FLAG_REVOKED, @@ -251,19 +245,19 @@ static void construct_get_dest_keyring(struct key **_dest_keyring) } case KEY_REQKEY_DEFL_THREAD_KEYRING: - dest_keyring = key_get(tsk->cred->thread_keyring); + dest_keyring = key_get(cred->thread_keyring); if (dest_keyring) break; case KEY_REQKEY_DEFL_PROCESS_KEYRING: - dest_keyring = key_get(tsk->signal->process_keyring); + dest_keyring = key_get(cred->tgcred->process_keyring); if (dest_keyring) break; case KEY_REQKEY_DEFL_SESSION_KEYRING: rcu_read_lock(); dest_keyring = key_get( - rcu_dereference(tsk->signal->session_keyring)); + rcu_dereference(cred->tgcred->session_keyring)); rcu_read_unlock(); if (dest_keyring) @@ -271,11 +265,11 @@ static void construct_get_dest_keyring(struct key **_dest_keyring) case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: dest_keyring = - key_get(tsk->cred->user->session_keyring); + key_get(cred->user->session_keyring); break; case KEY_REQKEY_DEFL_USER_KEYRING: - dest_keyring = key_get(tsk->cred->user->uid_keyring); + dest_keyring = key_get(cred->user->uid_keyring); break; case KEY_REQKEY_DEFL_GROUP_KEYRING: -- cgit v1.2.3 From 745ca2475a6ac596e3d8d37c2759c0fbe2586227 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:22 +1100 Subject: CRED: Pass credentials through dentry_open() Pass credentials through dentry_open() so that the COW creds patch can have SELinux's flush_unauthorized_files() pass the appropriate creds back to itself when it opens its null chardev. The security_dentry_open() call also now takes a creds pointer, as does the dentry_open hook in struct security_operations. Signed-off-by: David Howells Acked-by: James Morris Signed-off-by: James Morris --- arch/powerpc/platforms/cell/spufs/inode.c | 4 ++-- arch/um/drivers/mconsole_kern.c | 3 ++- fs/autofs4/dev-ioctl.c | 3 ++- fs/ecryptfs/ecryptfs_kernel.h | 3 ++- fs/ecryptfs/kthread.c | 9 +++++---- fs/ecryptfs/main.c | 3 ++- fs/exportfs/expfs.c | 4 +++- fs/hppfs/hppfs.c | 6 ++++-- fs/nfsctl.c | 3 ++- fs/nfsd/nfs4recover.c | 3 ++- fs/nfsd/vfs.c | 3 ++- fs/open.c | 17 +++++++++++------ fs/xfs/linux-2.6/xfs_ioctl.c | 3 ++- include/linux/fs.h | 4 +++- include/linux/security.h | 7 ++++--- ipc/mqueue.c | 11 +++++++---- security/capability.c | 2 +- security/security.c | 4 ++-- security/selinux/hooks.c | 15 +++++++++------ 19 files changed, 67 insertions(+), 40 deletions(-) (limited to 'include') diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c index e128ce7f0993..6296bfd9cb0b 100644 --- a/arch/powerpc/platforms/cell/spufs/inode.c +++ b/arch/powerpc/platforms/cell/spufs/inode.c @@ -323,7 +323,7 @@ static int spufs_context_open(struct dentry *dentry, struct vfsmount *mnt) goto out; } - filp = dentry_open(dentry, mnt, O_RDONLY); + filp = dentry_open(dentry, mnt, O_RDONLY, current_cred()); if (IS_ERR(filp)) { put_unused_fd(ret); ret = PTR_ERR(filp); @@ -562,7 +562,7 @@ static int spufs_gang_open(struct dentry *dentry, struct vfsmount *mnt) goto out; } - filp = dentry_open(dentry, mnt, O_RDONLY); + filp = dentry_open(dentry, mnt, O_RDONLY, current_cred()); if (IS_ERR(filp)) { put_unused_fd(ret); ret = PTR_ERR(filp); diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c index 19d579d74d27..16d3b3789a50 100644 --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -159,7 +159,8 @@ void mconsole_proc(struct mc_request *req) goto out_kill; } - file = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY); + file = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY, + current_cred()); if (IS_ERR(file)) { mconsole_reply(req, "Failed to open file", 1, 0); goto out_kill; diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c index 625abf5422e2..ec16255d27dd 100644 --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -307,7 +307,8 @@ static int autofs_dev_ioctl_open_mountpoint(const char *path, dev_t devid) goto out; } - filp = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY); + filp = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY, + current_cred()); if (IS_ERR(filp)) { err = PTR_ERR(filp); goto out; diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index 3504cf9df358..a75026d35d16 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -691,7 +691,8 @@ int ecryptfs_init_kthread(void); void ecryptfs_destroy_kthread(void); int ecryptfs_privileged_open(struct file **lower_file, struct dentry *lower_dentry, - struct vfsmount *lower_mnt); + struct vfsmount *lower_mnt, + const struct cred *cred); int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry); #endif /* #ifndef ECRYPTFS_KERNEL_H */ diff --git a/fs/ecryptfs/kthread.c b/fs/ecryptfs/kthread.c index c440c6b58b2d..c6d7a4d748a0 100644 --- a/fs/ecryptfs/kthread.c +++ b/fs/ecryptfs/kthread.c @@ -73,7 +73,7 @@ static int ecryptfs_threadfn(void *ignored) mntget(req->lower_mnt); (*req->lower_file) = dentry_open( req->lower_dentry, req->lower_mnt, - (O_RDWR | O_LARGEFILE)); + (O_RDWR | O_LARGEFILE), current_cred()); req->flags |= ECRYPTFS_REQ_PROCESSED; } wake_up(&req->wait); @@ -132,7 +132,8 @@ void ecryptfs_destroy_kthread(void) */ int ecryptfs_privileged_open(struct file **lower_file, struct dentry *lower_dentry, - struct vfsmount *lower_mnt) + struct vfsmount *lower_mnt, + const struct cred *cred) { struct ecryptfs_open_req *req; int rc = 0; @@ -143,7 +144,7 @@ int ecryptfs_privileged_open(struct file **lower_file, dget(lower_dentry); mntget(lower_mnt); (*lower_file) = dentry_open(lower_dentry, lower_mnt, - (O_RDWR | O_LARGEFILE)); + (O_RDWR | O_LARGEFILE), cred); if (!IS_ERR(*lower_file)) goto out; req = kmem_cache_alloc(ecryptfs_open_req_cache, GFP_KERNEL); @@ -184,7 +185,7 @@ int ecryptfs_privileged_open(struct file **lower_file, dget(lower_dentry); mntget(lower_mnt); (*lower_file) = dentry_open(lower_dentry, lower_mnt, - (O_RDONLY | O_LARGEFILE)); + (O_RDONLY | O_LARGEFILE), cred); if (IS_ERR(*lower_file)) { rc = PTR_ERR(*req->lower_file); (*lower_file) = NULL; diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 64d2ba980df4..fd630713c5c7 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -115,6 +115,7 @@ void __ecryptfs_printk(const char *fmt, ...) */ int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) { + const struct cred *cred = current_cred(); struct ecryptfs_inode_info *inode_info = ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); int rc = 0; @@ -127,7 +128,7 @@ int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); rc = ecryptfs_privileged_open(&inode_info->lower_file, - lower_dentry, lower_mnt); + lower_dentry, lower_mnt, cred); if (rc || IS_ERR(inode_info->lower_file)) { printk(KERN_ERR "Error opening lower persistent file " "for lower_dentry [0x%p] and lower_mnt [0x%p]; " diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 80246bad1b7f..ec1fb918200f 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -14,6 +14,7 @@ #include #include #include +#include #define dprintk(fmt, args...) do{}while(0) @@ -249,6 +250,7 @@ static int filldir_one(void * __buf, const char * name, int len, static int get_name(struct vfsmount *mnt, struct dentry *dentry, char *name, struct dentry *child) { + const struct cred *cred = current_cred(); struct inode *dir = dentry->d_inode; int error; struct file *file; @@ -263,7 +265,7 @@ static int get_name(struct vfsmount *mnt, struct dentry *dentry, /* * Open the directory ... */ - file = dentry_open(dget(dentry), mntget(mnt), O_RDONLY); + file = dentry_open(dget(dentry), mntget(mnt), O_RDONLY, cred); error = PTR_ERR(file); if (IS_ERR(file)) goto out; diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c index 2b3d1828db99..795e2c130ad7 100644 --- a/fs/hppfs/hppfs.c +++ b/fs/hppfs/hppfs.c @@ -426,6 +426,7 @@ static int file_mode(int fmode) static int hppfs_open(struct inode *inode, struct file *file) { + const struct cred *cred = current_cred(); struct hppfs_private *data; struct vfsmount *proc_mnt; struct dentry *proc_dentry; @@ -446,7 +447,7 @@ static int hppfs_open(struct inode *inode, struct file *file) /* XXX This isn't closed anywhere */ data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt), - file_mode(file->f_mode)); + file_mode(file->f_mode), cred); err = PTR_ERR(data->proc_file); if (IS_ERR(data->proc_file)) goto out_free1; @@ -489,6 +490,7 @@ static int hppfs_open(struct inode *inode, struct file *file) static int hppfs_dir_open(struct inode *inode, struct file *file) { + const struct cred *cred = current_cred(); struct hppfs_private *data; struct vfsmount *proc_mnt; struct dentry *proc_dentry; @@ -502,7 +504,7 @@ static int hppfs_dir_open(struct inode *inode, struct file *file) proc_dentry = HPPFS_I(inode)->proc_dentry; proc_mnt = inode->i_sb->s_fs_info; data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt), - file_mode(file->f_mode)); + file_mode(file->f_mode), cred); err = PTR_ERR(data->proc_file); if (IS_ERR(data->proc_file)) goto out_free; diff --git a/fs/nfsctl.c b/fs/nfsctl.c index aed8145d9087..cc4ef2642a51 100644 --- a/fs/nfsctl.c +++ b/fs/nfsctl.c @@ -41,7 +41,8 @@ static struct file *do_open(char *name, int flags) error = may_open(&nd, MAY_WRITE, FMODE_WRITE); if (!error) - return dentry_open(nd.path.dentry, nd.path.mnt, flags); + return dentry_open(nd.path.dentry, nd.path.mnt, flags, + current_cred()); path_put(&nd.path); return ERR_PTR(error); diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index a5e14e8695ea..632a50b4b371 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -226,7 +226,8 @@ nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f) nfs4_save_user(&uid, &gid); - filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY); + filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY, + current_cred()); status = PTR_ERR(filp); if (IS_ERR(filp)) goto out; diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 890d9a68c852..b59ec5a6ed24 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -671,6 +671,7 @@ __be32 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access, struct file **filp) { + const struct cred *cred = current_cred(); struct dentry *dentry; struct inode *inode; int flags = O_RDONLY|O_LARGEFILE; @@ -725,7 +726,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, DQUOT_INIT(inode); } *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt), - flags); + flags, cred); if (IS_ERR(*filp)) host_err = PTR_ERR(*filp); out_nfserr: diff --git a/fs/open.c b/fs/open.c index b1238e195e7e..f96eaab280a3 100644 --- a/fs/open.c +++ b/fs/open.c @@ -783,7 +783,8 @@ static inline int __get_file_write_access(struct inode *inode, static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, struct file *f, - int (*open)(struct inode *, struct file *)) + int (*open)(struct inode *, struct file *), + const struct cred *cred) { struct inode *inode; int error; @@ -807,7 +808,7 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, f->f_op = fops_get(inode->i_fop); file_move(f, &inode->i_sb->s_files); - error = security_dentry_open(f); + error = security_dentry_open(f, cred); if (error) goto cleanup_all; @@ -882,6 +883,8 @@ cleanup_file: struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, int (*open)(struct inode *, struct file *)) { + const struct cred *cred = current_cred(); + if (IS_ERR(nd->intent.open.file)) goto out; if (IS_ERR(dentry)) @@ -889,7 +892,7 @@ struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), nd->intent.open.flags - 1, nd->intent.open.file, - open); + open, cred); out: return nd->intent.open.file; out_err: @@ -908,6 +911,7 @@ EXPORT_SYMBOL_GPL(lookup_instantiate_filp); */ struct file *nameidata_to_filp(struct nameidata *nd, int flags) { + const struct cred *cred = current_cred(); struct file *filp; /* Pick up the filp from the open intent */ @@ -915,7 +919,7 @@ struct file *nameidata_to_filp(struct nameidata *nd, int flags) /* Has the filesystem initialised the file for us? */ if (filp->f_path.dentry == NULL) filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp, - NULL); + NULL, cred); else path_put(&nd->path); return filp; @@ -925,7 +929,8 @@ struct file *nameidata_to_filp(struct nameidata *nd, int flags) * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an * error. */ -struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) +struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, + const struct cred *cred) { int error; struct file *f; @@ -950,7 +955,7 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) return ERR_PTR(error); } - return __dentry_open(dentry, mnt, flags, f, NULL); + return __dentry_open(dentry, mnt, flags, f, NULL, cred); } EXPORT_SYMBOL(dentry_open); diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c index 67c72aec97e6..281cbd5a25cf 100644 --- a/fs/xfs/linux-2.6/xfs_ioctl.c +++ b/fs/xfs/linux-2.6/xfs_ioctl.c @@ -256,6 +256,7 @@ xfs_open_by_handle( struct file *parfilp, struct inode *parinode) { + const struct cred *cred = current_cred(); int error; int new_fd; int permflag; @@ -321,7 +322,7 @@ xfs_open_by_handle( mntget(parfilp->f_path.mnt); /* Create file pointer. */ - filp = dentry_open(dentry, parfilp->f_path.mnt, hreq.oflags); + filp = dentry_open(dentry, parfilp->f_path.mnt, hreq.oflags, cred); if (IS_ERR(filp)) { put_unused_fd(new_fd); return -XFS_ERROR(-PTR_ERR(filp)); diff --git a/include/linux/fs.h b/include/linux/fs.h index b3d404aaabed..3bfec1327b8d 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -315,6 +315,7 @@ struct poll_table_struct; struct kstatfs; struct vm_area_struct; struct vfsmount; +struct cred; extern void __init inode_init(void); extern void __init inode_init_early(void); @@ -1673,7 +1674,8 @@ extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs, extern long do_sys_open(int dfd, const char __user *filename, int flags, int mode); extern struct file *filp_open(const char *, int, int); -extern struct file * dentry_open(struct dentry *, struct vfsmount *, int); +extern struct file * dentry_open(struct dentry *, struct vfsmount *, int, + const struct cred *); extern int filp_close(struct file *, fl_owner_t id); extern char * getname(const char __user *); diff --git a/include/linux/security.h b/include/linux/security.h index 9239cc11eb9c..7e9fe046a0d1 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1402,7 +1402,7 @@ struct security_operations { int (*file_send_sigiotask) (struct task_struct *tsk, struct fown_struct *fown, int sig); int (*file_receive) (struct file *file); - int (*dentry_open) (struct file *file); + int (*dentry_open) (struct file *file, const struct cred *cred); int (*task_create) (unsigned long clone_flags); int (*cred_alloc_security) (struct cred *cred); @@ -1658,7 +1658,7 @@ int security_file_set_fowner(struct file *file); int security_file_send_sigiotask(struct task_struct *tsk, struct fown_struct *fown, int sig); int security_file_receive(struct file *file); -int security_dentry_open(struct file *file); +int security_dentry_open(struct file *file, const struct cred *cred); int security_task_create(unsigned long clone_flags); int security_cred_alloc(struct cred *cred); void security_cred_free(struct cred *cred); @@ -2171,7 +2171,8 @@ static inline int security_file_receive(struct file *file) return 0; } -static inline int security_dentry_open(struct file *file) +static inline int security_dentry_open(struct file *file, + const struct cred *cred) { return 0; } diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 1151881ccb9a..d9393f8e4c3e 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -594,6 +594,7 @@ static int mq_attr_ok(struct mq_attr *attr) static struct file *do_create(struct dentry *dir, struct dentry *dentry, int oflag, mode_t mode, struct mq_attr __user *u_attr) { + const struct cred *cred = current_cred(); struct mq_attr attr; struct file *result; int ret; @@ -618,7 +619,7 @@ static struct file *do_create(struct dentry *dir, struct dentry *dentry, if (ret) goto out_drop_write; - result = dentry_open(dentry, mqueue_mnt, oflag); + result = dentry_open(dentry, mqueue_mnt, oflag, cred); /* * dentry_open() took a persistent mnt_want_write(), * so we can now drop this one. @@ -637,8 +638,10 @@ out: /* Opens existing queue */ static struct file *do_open(struct dentry *dentry, int oflag) { -static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, - MAY_READ | MAY_WRITE }; + const struct cred *cred = current_cred(); + + static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, + MAY_READ | MAY_WRITE }; if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { dput(dentry); @@ -652,7 +655,7 @@ static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, return ERR_PTR(-EACCES); } - return dentry_open(dentry, mqueue_mnt, oflag); + return dentry_open(dentry, mqueue_mnt, oflag, cred); } asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode, diff --git a/security/capability.c b/security/capability.c index 6c4b5137ca7b..fac2f61b69a9 100644 --- a/security/capability.c +++ b/security/capability.c @@ -330,7 +330,7 @@ static int cap_file_receive(struct file *file) return 0; } -static int cap_dentry_open(struct file *file) +static int cap_dentry_open(struct file *file, const struct cred *cred) { return 0; } diff --git a/security/security.c b/security/security.c index d058f7d5b10a..f40a0a04c3c2 100644 --- a/security/security.c +++ b/security/security.c @@ -606,9 +606,9 @@ int security_file_receive(struct file *file) return security_ops->file_receive(file); } -int security_dentry_open(struct file *file) +int security_dentry_open(struct file *file, const struct cred *cred) { - return security_ops->dentry_open(file); + return security_ops->dentry_open(file, cred); } int security_task_create(unsigned long clone_flags) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index cc6e5a3f10cc..f20cbd681ba6 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2150,9 +2150,9 @@ extern struct vfsmount *selinuxfs_mount; extern struct dentry *selinux_null; /* Derived from fs/exec.c:flush_old_files. */ -static inline void flush_unauthorized_files(struct files_struct *files) +static inline void flush_unauthorized_files(const struct cred *cred, + struct files_struct *files) { - const struct cred *cred = current_cred(); struct avc_audit_data ad; struct file *file, *devnull = NULL; struct tty_struct *tty; @@ -2222,7 +2222,10 @@ static inline void flush_unauthorized_files(struct files_struct *files) if (devnull) { get_file(devnull); } else { - devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR); + devnull = dentry_open( + dget(selinux_null), + mntget(selinuxfs_mount), + O_RDWR, cred); if (IS_ERR(devnull)) { devnull = NULL; put_unused_fd(fd); @@ -2302,6 +2305,7 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) */ static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) { + const struct cred *cred = current_cred(); struct task_security_struct *tsec; struct rlimit *rlim, *initrlim; struct itimerval itimer; @@ -2321,7 +2325,7 @@ static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) return; /* Close files for which the new task SID is not authorized. */ - flush_unauthorized_files(current->files); + flush_unauthorized_files(cred, current->files); /* Check whether the new SID can inherit signal state from the old SID. If not, clear itimers to avoid @@ -3202,9 +3206,8 @@ static int selinux_file_receive(struct file *file) return file_has_perm(cred, file, file_to_av(file)); } -static int selinux_dentry_open(struct file *file) +static int selinux_dentry_open(struct file *file, const struct cred *cred) { - const struct cred *cred = current_cred(); struct file_security_struct *fsec; struct inode *inode; struct inode_security_struct *isec; -- cgit v1.2.3 From d84f4f992cbd76e8f39c488cf0c5d123843923b1 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:23 +1100 Subject: CRED: Inaugurate COW credentials Inaugurate copy-on-write credentials management. This uses RCU to manage the credentials pointer in the task_struct with respect to accesses by other tasks. A process may only modify its own credentials, and so does not need locking to access or modify its own credentials. A mutex (cred_replace_mutex) is added to the task_struct to control the effect of PTRACE_ATTACHED on credential calculations, particularly with respect to execve(). With this patch, the contents of an active credentials struct may not be changed directly; rather a new set of credentials must be prepared, modified and committed using something like the following sequence of events: struct cred *new = prepare_creds(); int ret = blah(new); if (ret < 0) { abort_creds(new); return ret; } return commit_creds(new); There are some exceptions to this rule: the keyrings pointed to by the active credentials may be instantiated - keyrings violate the COW rule as managing COW keyrings is tricky, given that it is possible for a task to directly alter the keys in a keyring in use by another task. To help enforce this, various pointers to sets of credentials, such as those in the task_struct, are declared const. The purpose of this is compile-time discouragement of altering credentials through those pointers. Once a set of credentials has been made public through one of these pointers, it may not be modified, except under special circumstances: (1) Its reference count may incremented and decremented. (2) The keyrings to which it points may be modified, but not replaced. The only safe way to modify anything else is to create a replacement and commit using the functions described in Documentation/credentials.txt (which will be added by a later patch). This patch and the preceding patches have been tested with the LTP SELinux testsuite. This patch makes several logical sets of alteration: (1) execve(). This now prepares and commits credentials in various places in the security code rather than altering the current creds directly. (2) Temporary credential overrides. do_coredump() and sys_faccessat() now prepare their own credentials and temporarily override the ones currently on the acting thread, whilst preventing interference from other threads by holding cred_replace_mutex on the thread being dumped. This will be replaced in a future patch by something that hands down the credentials directly to the functions being called, rather than altering the task's objective credentials. (3) LSM interface. A number of functions have been changed, added or removed: (*) security_capset_check(), ->capset_check() (*) security_capset_set(), ->capset_set() Removed in favour of security_capset(). (*) security_capset(), ->capset() New. This is passed a pointer to the new creds, a pointer to the old creds and the proposed capability sets. It should fill in the new creds or return an error. All pointers, barring the pointer to the new creds, are now const. (*) security_bprm_apply_creds(), ->bprm_apply_creds() Changed; now returns a value, which will cause the process to be killed if it's an error. (*) security_task_alloc(), ->task_alloc_security() Removed in favour of security_prepare_creds(). (*) security_cred_free(), ->cred_free() New. Free security data attached to cred->security. (*) security_prepare_creds(), ->cred_prepare() New. Duplicate any security data attached to cred->security. (*) security_commit_creds(), ->cred_commit() New. Apply any security effects for the upcoming installation of new security by commit_creds(). (*) security_task_post_setuid(), ->task_post_setuid() Removed in favour of security_task_fix_setuid(). (*) security_task_fix_setuid(), ->task_fix_setuid() Fix up the proposed new credentials for setuid(). This is used by cap_set_fix_setuid() to implicitly adjust capabilities in line with setuid() changes. Changes are made to the new credentials, rather than the task itself as in security_task_post_setuid(). (*) security_task_reparent_to_init(), ->task_reparent_to_init() Removed. Instead the task being reparented to init is referred directly to init's credentials. NOTE! This results in the loss of some state: SELinux's osid no longer records the sid of the thread that forked it. (*) security_key_alloc(), ->key_alloc() (*) security_key_permission(), ->key_permission() Changed. These now take cred pointers rather than task pointers to refer to the security context. (4) sys_capset(). This has been simplified and uses less locking. The LSM functions it calls have been merged. (5) reparent_to_kthreadd(). This gives the current thread the same credentials as init by simply using commit_thread() to point that way. (6) __sigqueue_alloc() and switch_uid() __sigqueue_alloc() can't stop the target task from changing its creds beneath it, so this function gets a reference to the currently applicable user_struct which it then passes into the sigqueue struct it returns if successful. switch_uid() is now called from commit_creds(), and possibly should be folded into that. commit_creds() should take care of protecting __sigqueue_alloc(). (7) [sg]et[ug]id() and co and [sg]et_current_groups. The set functions now all use prepare_creds(), commit_creds() and abort_creds() to build and check a new set of credentials before applying it. security_task_set[ug]id() is called inside the prepared section. This guarantees that nothing else will affect the creds until we've finished. The calling of set_dumpable() has been moved into commit_creds(). Much of the functionality of set_user() has been moved into commit_creds(). The get functions all simply access the data directly. (8) security_task_prctl() and cap_task_prctl(). security_task_prctl() has been modified to return -ENOSYS if it doesn't want to handle a function, or otherwise return the return value directly rather than through an argument. Additionally, cap_task_prctl() now prepares a new set of credentials, even if it doesn't end up using it. (9) Keyrings. A number of changes have been made to the keyrings code: (a) switch_uid_keyring(), copy_keys(), exit_keys() and suid_keys() have all been dropped and built in to the credentials functions directly. They may want separating out again later. (b) key_alloc() and search_process_keyrings() now take a cred pointer rather than a task pointer to specify the security context. (c) copy_creds() gives a new thread within the same thread group a new thread keyring if its parent had one, otherwise it discards the thread keyring. (d) The authorisation key now points directly to the credentials to extend the search into rather pointing to the task that carries them. (e) Installing thread, process or session keyrings causes a new set of credentials to be created, even though it's not strictly necessary for process or session keyrings (they're shared). (10) Usermode helper. The usermode helper code now carries a cred struct pointer in its subprocess_info struct instead of a new session keyring pointer. This set of credentials is derived from init_cred and installed on the new process after it has been cloned. call_usermodehelper_setup() allocates the new credentials and call_usermodehelper_freeinfo() discards them if they haven't been used. A special cred function (prepare_usermodeinfo_creds()) is provided specifically for call_usermodehelper_setup() to call. call_usermodehelper_setkeys() adjusts the credentials to sport the supplied keyring as the new session keyring. (11) SELinux. SELinux has a number of changes, in addition to those to support the LSM interface changes mentioned above: (a) selinux_setprocattr() no longer does its check for whether the current ptracer can access processes with the new SID inside the lock that covers getting the ptracer's SID. Whilst this lock ensures that the check is done with the ptracer pinned, the result is only valid until the lock is released, so there's no point doing it inside the lock. (12) is_single_threaded(). This function has been extracted from selinux_setprocattr() and put into a file of its own in the lib/ directory as join_session_keyring() now wants to use it too. The code in SELinux just checked to see whether a task shared mm_structs with other tasks (CLONE_VM), but that isn't good enough. We really want to know if they're part of the same thread group (CLONE_THREAD). (13) nfsd. The NFS server daemon now has to use the COW credentials to set the credentials it is going to use. It really needs to pass the credentials down to the functions it calls, but it can't do that until other patches in this series have been applied. Signed-off-by: David Howells Acked-by: James Morris Signed-off-by: James Morris --- fs/exec.c | 31 ++- fs/nfsd/auth.c | 92 ++++---- fs/nfsd/nfs4recover.c | 68 +++--- fs/nfsd/nfsfh.c | 11 +- fs/open.c | 31 ++- include/linux/audit.h | 22 +- include/linux/capability.h | 2 - include/linux/cred.h | 44 +++- include/linux/init_task.h | 2 + include/linux/key.h | 22 +- include/linux/sched.h | 6 +- include/linux/security.h | 178 +++++++--------- init/main.c | 1 + kernel/auditsc.c | 42 ++-- kernel/capability.c | 78 +++---- kernel/cred-internals.h | 21 ++ kernel/cred.c | 321 ++++++++++++++++++++++++---- kernel/exit.c | 9 +- kernel/fork.c | 7 +- kernel/kmod.c | 30 ++- kernel/ptrace.c | 9 + kernel/signal.c | 10 +- kernel/sys.c | 450 +++++++++++++++++++++------------------ kernel/user.c | 37 +--- kernel/user_namespace.c | 12 +- lib/Makefile | 2 +- net/rxrpc/ar-key.c | 6 +- security/capability.c | 21 +- security/commoncap.c | 265 +++++++++++------------ security/keys/internal.h | 17 +- security/keys/key.c | 25 +-- security/keys/keyctl.c | 95 ++++++--- security/keys/keyring.c | 14 +- security/keys/permission.c | 24 ++- security/keys/proc.c | 8 +- security/keys/process_keys.c | 333 ++++++++++++++--------------- security/keys/request_key.c | 29 ++- security/keys/request_key_auth.c | 41 ++-- security/security.c | 58 +++-- security/selinux/hooks.c | 286 ++++++++++++------------- security/smack/smack_lsm.c | 82 ++++--- 41 files changed, 1603 insertions(+), 1239 deletions(-) create mode 100644 kernel/cred-internals.h (limited to 'include') diff --git a/fs/exec.c b/fs/exec.c index a5330e1a2216..9bd3559ddece 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1007,13 +1007,12 @@ int flush_old_exec(struct linux_binprm * bprm) */ current->mm->task_size = TASK_SIZE; - if (bprm->e_uid != current_euid() || bprm->e_gid != current_egid()) { - suid_keys(current); + if (bprm->e_uid != current_euid() || + bprm->e_gid != current_egid()) { set_dumpable(current->mm, suid_dumpable); current->pdeath_signal = 0; } else if (file_permission(bprm->file, MAY_READ) || (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) { - suid_keys(current); set_dumpable(current->mm, suid_dumpable); } @@ -1096,10 +1095,8 @@ void compute_creds(struct linux_binprm *bprm) { int unsafe; - if (bprm->e_uid != current_uid()) { - suid_keys(current); + if (bprm->e_uid != current_uid()) current->pdeath_signal = 0; - } exec_keys(current); task_lock(current); @@ -1709,8 +1706,9 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs) struct linux_binfmt * binfmt; struct inode * inode; struct file * file; + const struct cred *old_cred; + struct cred *cred; int retval = 0; - int fsuid = current_fsuid(); int flag = 0; int ispipe = 0; unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur; @@ -1723,12 +1721,20 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs) binfmt = current->binfmt; if (!binfmt || !binfmt->core_dump) goto fail; + + cred = prepare_creds(); + if (!cred) { + retval = -ENOMEM; + goto fail; + } + down_write(&mm->mmap_sem); /* * If another thread got here first, or we are not dumpable, bail out. */ if (mm->core_state || !get_dumpable(mm)) { up_write(&mm->mmap_sem); + put_cred(cred); goto fail; } @@ -1739,12 +1745,16 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs) */ if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ flag = O_EXCL; /* Stop rewrite attacks */ - current->cred->fsuid = 0; /* Dump root private */ + cred->fsuid = 0; /* Dump root private */ } retval = coredump_wait(exit_code, &core_state); - if (retval < 0) + if (retval < 0) { + put_cred(cred); goto fail; + } + + old_cred = override_creds(cred); /* * Clear any false indication of pending signals that might @@ -1835,7 +1845,8 @@ fail_unlock: if (helper_argv) argv_free(helper_argv); - current->cred->fsuid = fsuid; + revert_creds(old_cred); + put_cred(cred); coredump_finish(mm); fail: return retval; diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c index 808fc03a6fbd..836ffa1047d9 100644 --- a/fs/nfsd/auth.c +++ b/fs/nfsd/auth.c @@ -27,55 +27,67 @@ int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp) int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp) { - struct cred *act_as = current->cred ; - struct svc_cred cred = rqstp->rq_cred; + struct group_info *rqgi; + struct group_info *gi; + struct cred *new; int i; int flags = nfsexp_flags(rqstp, exp); int ret; + new = prepare_creds(); + if (!new) + return -ENOMEM; + + new->fsuid = rqstp->rq_cred.cr_uid; + new->fsgid = rqstp->rq_cred.cr_gid; + + rqgi = rqstp->rq_cred.cr_group_info; + if (flags & NFSEXP_ALLSQUASH) { - cred.cr_uid = exp->ex_anon_uid; - cred.cr_gid = exp->ex_anon_gid; - cred.cr_group_info = groups_alloc(0); + new->fsuid = exp->ex_anon_uid; + new->fsgid = exp->ex_anon_gid; + gi = groups_alloc(0); } else if (flags & NFSEXP_ROOTSQUASH) { - struct group_info *gi; - if (!cred.cr_uid) - cred.cr_uid = exp->ex_anon_uid; - if (!cred.cr_gid) - cred.cr_gid = exp->ex_anon_gid; - gi = groups_alloc(cred.cr_group_info->ngroups); - if (gi) - for (i = 0; i < cred.cr_group_info->ngroups; i++) { - if (!GROUP_AT(cred.cr_group_info, i)) - GROUP_AT(gi, i) = exp->ex_anon_gid; - else - GROUP_AT(gi, i) = GROUP_AT(cred.cr_group_info, i); - } - cred.cr_group_info = gi; - } else - get_group_info(cred.cr_group_info); - - if (cred.cr_uid != (uid_t) -1) - act_as->fsuid = cred.cr_uid; - else - act_as->fsuid = exp->ex_anon_uid; - if (cred.cr_gid != (gid_t) -1) - act_as->fsgid = cred.cr_gid; - else - act_as->fsgid = exp->ex_anon_gid; + if (!new->fsuid) + new->fsuid = exp->ex_anon_uid; + if (!new->fsgid) + new->fsgid = exp->ex_anon_gid; - if (!cred.cr_group_info) - return -ENOMEM; - ret = set_groups(act_as, cred.cr_group_info); - put_group_info(cred.cr_group_info); - if ((cred.cr_uid)) { - act_as->cap_effective = - cap_drop_nfsd_set(act_as->cap_effective); + gi = groups_alloc(rqgi->ngroups); + if (!gi) + goto oom; + + for (i = 0; i < rqgi->ngroups; i++) { + if (!GROUP_AT(rqgi, i)) + GROUP_AT(gi, i) = exp->ex_anon_gid; + else + GROUP_AT(gi, i) = GROUP_AT(rqgi, i); + } } else { - act_as->cap_effective = - cap_raise_nfsd_set(act_as->cap_effective, - act_as->cap_permitted); + gi = get_group_info(rqgi); } + + if (new->fsuid == (uid_t) -1) + new->fsuid = exp->ex_anon_uid; + if (new->fsgid == (gid_t) -1) + new->fsgid = exp->ex_anon_gid; + + ret = set_groups(new, gi); + put_group_info(gi); + if (!ret) + goto error; + + if (new->uid) + new->cap_effective = cap_drop_nfsd_set(new->cap_effective); + else + new->cap_effective = cap_raise_nfsd_set(new->cap_effective, + new->cap_permitted); + return commit_creds(new); + +oom: + ret = -ENOMEM; +error: + abort_creds(new); return ret; } diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index 632a50b4b371..9371ea12d7fa 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -54,20 +54,26 @@ static struct path rec_dir; static int rec_dir_init = 0; -static void -nfs4_save_user(uid_t *saveuid, gid_t *savegid) +static int +nfs4_save_creds(const struct cred **original_creds) { - *saveuid = current->cred->fsuid; - *savegid = current->cred->fsgid; - current->cred->fsuid = 0; - current->cred->fsgid = 0; + struct cred *new; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + new->fsuid = 0; + new->fsgid = 0; + *original_creds = override_creds(new); + put_cred(new); + return 0; } static void -nfs4_reset_user(uid_t saveuid, gid_t savegid) +nfs4_reset_creds(const struct cred *original) { - current->cred->fsuid = saveuid; - current->cred->fsgid = savegid; + revert_creds(original); } static void @@ -129,10 +135,9 @@ nfsd4_sync_rec_dir(void) int nfsd4_create_clid_dir(struct nfs4_client *clp) { + const struct cred *original_cred; char *dname = clp->cl_recdir; struct dentry *dentry; - uid_t uid; - gid_t gid; int status; dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname); @@ -140,7 +145,9 @@ nfsd4_create_clid_dir(struct nfs4_client *clp) if (!rec_dir_init || clp->cl_firststate) return 0; - nfs4_save_user(&uid, &gid); + status = nfs4_save_creds(&original_cred); + if (status < 0) + return status; /* lock the parent */ mutex_lock(&rec_dir.dentry->d_inode->i_mutex); @@ -168,7 +175,7 @@ out_unlock: clp->cl_firststate = 1; nfsd4_sync_rec_dir(); } - nfs4_reset_user(uid, gid); + nfs4_reset_creds(original_cred); dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status); return status; } @@ -211,20 +218,21 @@ nfsd4_build_dentrylist(void *arg, const char *name, int namlen, static int nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f) { + const struct cred *original_cred; struct file *filp; struct dentry_list_arg dla = { .parent = dir, }; struct list_head *dentries = &dla.dentries; struct dentry_list *child; - uid_t uid; - gid_t gid; int status; if (!rec_dir_init) return 0; - nfs4_save_user(&uid, &gid); + status = nfs4_save_creds(&original_cred); + if (status < 0) + return status; filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY, current_cred()); @@ -250,7 +258,7 @@ out: dput(child->dentry); kfree(child); } - nfs4_reset_user(uid, gid); + nfs4_reset_creds(original_cred); return status; } @@ -312,8 +320,7 @@ out: void nfsd4_remove_clid_dir(struct nfs4_client *clp) { - uid_t uid; - gid_t gid; + const struct cred *original_cred; int status; if (!rec_dir_init || !clp->cl_firststate) @@ -323,9 +330,13 @@ nfsd4_remove_clid_dir(struct nfs4_client *clp) if (status) goto out; clp->cl_firststate = 0; - nfs4_save_user(&uid, &gid); + + status = nfs4_save_creds(&original_cred); + if (status < 0) + goto out; + status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1); - nfs4_reset_user(uid, gid); + nfs4_reset_creds(original_cred); if (status == 0) nfsd4_sync_rec_dir(); mnt_drop_write(rec_dir.mnt); @@ -402,16 +413,21 @@ nfsd4_recdir_load(void) { void nfsd4_init_recdir(char *rec_dirname) { - uid_t uid = 0; - gid_t gid = 0; - int status; + const struct cred *original_cred; + int status; printk("NFSD: Using %s as the NFSv4 state recovery directory\n", rec_dirname); BUG_ON(rec_dir_init); - nfs4_save_user(&uid, &gid); + status = nfs4_save_creds(&original_cred); + if (status < 0) { + printk("NFSD: Unable to change credentials to find recovery" + " directory: error %d\n", + status); + return; + } status = kern_path(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &rec_dir); @@ -421,7 +437,7 @@ nfsd4_init_recdir(char *rec_dirname) if (!status) rec_dir_init = 1; - nfs4_reset_user(uid, gid); + nfs4_reset_creds(original_cred); } void diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c index e67cfaea0865..f0da7d9c3a92 100644 --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -186,9 +186,14 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp) * access control settings being in effect, we cannot * fix that case easily. */ - current->cred->cap_effective = - cap_raise_nfsd_set(current->cred->cap_effective, - current->cred->cap_permitted); + struct cred *new = prepare_creds(); + if (!new) + return nfserrno(-ENOMEM); + new->cap_effective = + cap_raise_nfsd_set(new->cap_effective, + new->cap_permitted); + put_cred(override_creds(new)); + put_cred(new); } else { error = nfsd_setuser_and_check_port(rqstp, exp); if (error) diff --git a/fs/open.c b/fs/open.c index f96eaab280a3..c0a426d5766c 100644 --- a/fs/open.c +++ b/fs/open.c @@ -425,30 +425,33 @@ out: */ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) { - struct cred *cred = current->cred; + const struct cred *old_cred; + struct cred *override_cred; struct path path; struct inode *inode; - int old_fsuid, old_fsgid; - kernel_cap_t uninitialized_var(old_cap); /* !SECURE_NO_SETUID_FIXUP */ int res; if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ return -EINVAL; - old_fsuid = cred->fsuid; - old_fsgid = cred->fsgid; + override_cred = prepare_creds(); + if (!override_cred) + return -ENOMEM; - cred->fsuid = cred->uid; - cred->fsgid = cred->gid; + override_cred->fsuid = override_cred->uid; + override_cred->fsgid = override_cred->gid; if (!issecure(SECURE_NO_SETUID_FIXUP)) { /* Clear the capabilities if we switch to a non-root user */ - if (current->cred->uid) - old_cap = cap_set_effective(__cap_empty_set); + if (override_cred->uid) + cap_clear(override_cred->cap_effective); else - old_cap = cap_set_effective(cred->cap_permitted); + override_cred->cap_effective = + override_cred->cap_permitted; } + old_cred = override_creds(override_cred); + res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); if (res) goto out; @@ -485,12 +488,8 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) out_path_release: path_put(&path); out: - cred->fsuid = old_fsuid; - cred->fsgid = old_fsgid; - - if (!issecure(SECURE_NO_SETUID_FIXUP)) - cap_set_effective(old_cap); - + revert_creds(old_cred); + put_cred(override_cred); return res; } diff --git a/include/linux/audit.h b/include/linux/audit.h index 6fbebac7b1bf..0b2fcb698a63 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -454,8 +454,10 @@ extern int __audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_pr extern int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len, unsigned int __user *u_msg_prio, const struct timespec __user *u_abs_timeout); extern int __audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification); extern int __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat); -extern void __audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_cap_t *pE); -extern int __audit_log_capset(pid_t pid, kernel_cap_t *eff, kernel_cap_t *inh, kernel_cap_t *perm); +extern int __audit_log_bprm_fcaps(struct linux_binprm *bprm, + const struct cred *new, + const struct cred *old); +extern int __audit_log_capset(pid_t pid, const struct cred *new, const struct cred *old); static inline int audit_ipc_obj(struct kern_ipc_perm *ipcp) { @@ -522,16 +524,20 @@ static inline int audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat) * * -Eric */ -static inline void audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_cap_t *pE) +static inline int audit_log_bprm_fcaps(struct linux_binprm *bprm, + const struct cred *new, + const struct cred *old) { if (unlikely(!audit_dummy_context())) - __audit_log_bprm_fcaps(bprm, pP, pE); + return __audit_log_bprm_fcaps(bprm, new, old); + return 0; } -static inline int audit_log_capset(pid_t pid, kernel_cap_t *eff, kernel_cap_t *inh, kernel_cap_t *perm) +static inline int audit_log_capset(pid_t pid, const struct cred *new, + const struct cred *old) { if (unlikely(!audit_dummy_context())) - return __audit_log_capset(pid, eff, inh, perm); + return __audit_log_capset(pid, new, old); return 0; } @@ -566,8 +572,8 @@ extern int audit_signals; #define audit_mq_timedreceive(d,l,p,t) ({ 0; }) #define audit_mq_notify(d,n) ({ 0; }) #define audit_mq_getsetattr(d,s) ({ 0; }) -#define audit_log_bprm_fcaps(b, p, e) do { ; } while (0) -#define audit_log_capset(pid, e, i, p) ({ 0; }) +#define audit_log_bprm_fcaps(b, ncr, ocr) ({ 0; }) +#define audit_log_capset(pid, ncr, ocr) ({ 0; }) #define audit_ptrace(t) ((void)0) #define audit_n_rules 0 #define audit_signals 0 diff --git a/include/linux/capability.h b/include/linux/capability.h index 7f26580a5a4d..e22f48c2a46f 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -519,8 +519,6 @@ extern const kernel_cap_t __cap_empty_set; extern const kernel_cap_t __cap_full_set; extern const kernel_cap_t __cap_init_eff_set; -kernel_cap_t cap_set_effective(const kernel_cap_t pE_new); - /** * has_capability - Determine if a task has a superior capability available * @t: The task in question diff --git a/include/linux/cred.h b/include/linux/cred.h index 62b9e532422d..eaf6fa695a04 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -84,6 +84,8 @@ struct thread_group_cred { struct key *process_keyring; /* keyring private to this process */ struct rcu_head rcu; /* RCU deletion hook */ }; + +extern void release_tgcred(struct cred *cred); #endif /* @@ -137,11 +139,30 @@ struct cred { struct user_struct *user; /* real user ID subscription */ struct group_info *group_info; /* supplementary groups for euid/fsgid */ struct rcu_head rcu; /* RCU deletion hook */ - spinlock_t lock; /* lock for pointer changes */ }; extern void __put_cred(struct cred *); extern int copy_creds(struct task_struct *, unsigned long); +extern struct cred *prepare_creds(void); +extern struct cred *prepare_usermodehelper_creds(void); +extern int commit_creds(struct cred *); +extern void abort_creds(struct cred *); +extern const struct cred *override_creds(const struct cred *) __deprecated; +extern void revert_creds(const struct cred *) __deprecated; +extern void __init cred_init(void); + +/** + * get_new_cred - Get a reference on a new set of credentials + * @cred: The new credentials to reference + * + * Get a reference on the specified set of new credentials. The caller must + * release the reference. + */ +static inline struct cred *get_new_cred(struct cred *cred) +{ + atomic_inc(&cred->usage); + return cred; +} /** * get_cred - Get a reference on a set of credentials @@ -150,10 +171,9 @@ extern int copy_creds(struct task_struct *, unsigned long); * Get a reference on the specified set of credentials. The caller must * release the reference. */ -static inline struct cred *get_cred(struct cred *cred) +static inline const struct cred *get_cred(const struct cred *cred) { - atomic_inc(&cred->usage); - return cred; + return get_new_cred((struct cred *) cred); } /** @@ -166,6 +186,8 @@ static inline struct cred *get_cred(struct cred *cred) static inline void put_cred(const struct cred *_cred) { struct cred *cred = (struct cred *) _cred; + + BUG_ON(atomic_read(&(cred)->usage) <= 0); if (atomic_dec_and_test(&(cred)->usage)) __put_cred(cred); } @@ -250,13 +272,13 @@ static inline void put_cred(const struct cred *_cred) __groups; \ }) -#define task_cred_xxx(task, xxx) \ -({ \ - __typeof__(task->cred->xxx) ___val; \ - rcu_read_lock(); \ - ___val = __task_cred((task))->xxx; \ - rcu_read_unlock(); \ - ___val; \ +#define task_cred_xxx(task, xxx) \ +({ \ + __typeof__(((struct cred *)NULL)->xxx) ___val; \ + rcu_read_lock(); \ + ___val = __task_cred((task))->xxx; \ + rcu_read_unlock(); \ + ___val; \ }) #define task_uid(task) (task_cred_xxx((task), uid)) diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 5e24c54b6dfd..08c3b24ad9a8 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -150,6 +150,8 @@ extern struct cred init_cred; .sibling = LIST_HEAD_INIT(tsk.sibling), \ .group_leader = &tsk, \ .cred = &init_cred, \ + .cred_exec_mutex = \ + __MUTEX_INITIALIZER(tsk.cred_exec_mutex), \ .comm = "swapper", \ .thread = INIT_THREAD, \ .fs = &init_fs, \ diff --git a/include/linux/key.h b/include/linux/key.h index 0836cc838b0c..69ecf0934b02 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -73,6 +73,7 @@ struct key; struct seq_file; struct user_struct; struct signal_struct; +struct cred; struct key_type; struct key_owner; @@ -181,7 +182,7 @@ struct key { extern struct key *key_alloc(struct key_type *type, const char *desc, uid_t uid, gid_t gid, - struct task_struct *ctx, + const struct cred *cred, key_perm_t perm, unsigned long flags); @@ -249,7 +250,7 @@ extern int key_unlink(struct key *keyring, struct key *key); extern struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, - struct task_struct *ctx, + const struct cred *cred, unsigned long flags, struct key *dest); @@ -276,22 +277,12 @@ extern ctl_table key_sysctls[]; /* * the userspace interface */ -extern void switch_uid_keyring(struct user_struct *new_user); -extern int copy_keys(unsigned long clone_flags, struct task_struct *tsk); -extern void exit_keys(struct task_struct *tsk); -extern int suid_keys(struct task_struct *tsk); +extern int install_thread_keyring_to_cred(struct cred *cred); extern int exec_keys(struct task_struct *tsk); extern void key_fsuid_changed(struct task_struct *tsk); extern void key_fsgid_changed(struct task_struct *tsk); extern void key_init(void); -#define __install_session_keyring(keyring) \ -({ \ - struct key *old_session = current->cred->tgcred->session_keyring; \ - current->cred->tgcred->session_keyring = keyring; \ - old_session; \ -}) - #else /* CONFIG_KEYS */ #define key_validate(k) 0 @@ -303,11 +294,6 @@ extern void key_init(void); #define make_key_ref(k, p) NULL #define key_ref_to_ptr(k) NULL #define is_key_possessed(k) 0 -#define switch_uid_keyring(u) do { } while(0) -#define __install_session_keyring(k) ({ NULL; }) -#define copy_keys(f,t) 0 -#define exit_keys(t) do { } while(0) -#define suid_keys(t) do { } while(0) #define exec_keys(t) do { } while(0) #define key_fsuid_changed(t) do { } while(0) #define key_fsgid_changed(t) do { } while(0) diff --git a/include/linux/sched.h b/include/linux/sched.h index 2913252989b3..121d655e460d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1145,7 +1145,8 @@ struct task_struct { struct list_head cpu_timers[3]; /* process credentials */ - struct cred *cred; /* actual/objective task credentials */ + const struct cred *cred; /* actual/objective task credentials (COW) */ + struct mutex cred_exec_mutex; /* execve vs ptrace cred calculation mutex */ char comm[TASK_COMM_LEN]; /* executable name excluding path - access with [gs]et_task_comm (which lock @@ -1720,7 +1721,6 @@ static inline struct user_struct *get_uid(struct user_struct *u) return u; } extern void free_uid(struct user_struct *); -extern void switch_uid(struct user_struct *); extern void release_uids(struct user_namespace *ns); #include @@ -1870,6 +1870,8 @@ static inline unsigned long wait_task_inactive(struct task_struct *p, #define for_each_process(p) \ for (p = &init_task ; (p = next_task(p)) != &init_task ; ) +extern bool is_single_threaded(struct task_struct *); + /* * Careful: do_each_thread/while_each_thread is a double loop so * 'break' will not work as expected - use goto instead. diff --git a/include/linux/security.h b/include/linux/security.h index 7e9fe046a0d1..68be11251447 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -53,24 +53,21 @@ extern int cap_settime(struct timespec *ts, struct timezone *tz); extern int cap_ptrace_may_access(struct task_struct *child, unsigned int mode); extern int cap_ptrace_traceme(struct task_struct *parent); extern int cap_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); -extern int cap_capset_check(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted); -extern void cap_capset_set(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted); +extern int cap_capset(struct cred *new, const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted); extern int cap_bprm_set_security(struct linux_binprm *bprm); -extern void cap_bprm_apply_creds(struct linux_binprm *bprm, int unsafe); +extern int cap_bprm_apply_creds(struct linux_binprm *bprm, int unsafe); extern int cap_bprm_secureexec(struct linux_binprm *bprm); extern int cap_inode_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags); extern int cap_inode_removexattr(struct dentry *dentry, const char *name); extern int cap_inode_need_killpriv(struct dentry *dentry); extern int cap_inode_killpriv(struct dentry *dentry); -extern int cap_task_post_setuid(uid_t old_ruid, uid_t old_euid, uid_t old_suid, int flags); -extern void cap_task_reparent_to_init(struct task_struct *p); +extern int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags); extern int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, - unsigned long arg4, unsigned long arg5, long *rc_p); + unsigned long arg4, unsigned long arg5); extern int cap_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp); extern int cap_task_setioprio(struct task_struct *p, int ioprio); extern int cap_task_setnice(struct task_struct *p, int nice); @@ -170,8 +167,8 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * Compute and set the security attributes of a process being transformed * by an execve operation based on the old attributes (current->security) * and the information saved in @bprm->security by the set_security hook. - * Since this hook function (and its caller) are void, this hook can not - * return an error. However, it can leave the security attributes of the + * Since this function may return an error, in which case the process will + * be killed. However, it can leave the security attributes of the * process unchanged if an access failure occurs at this point. * bprm_apply_creds is called under task_lock. @unsafe indicates various * reasons why it may be unsafe to change security state. @@ -593,15 +590,18 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * manual page for definitions of the @clone_flags. * @clone_flags contains the flags indicating what should be shared. * Return 0 if permission is granted. - * @cred_alloc_security: - * @cred contains the cred struct for child process. - * Allocate and attach a security structure to the cred->security field. - * The security field is initialized to NULL when the task structure is - * allocated. - * Return 0 if operation was successful. * @cred_free: * @cred points to the credentials. * Deallocate and clear the cred->security field in a set of credentials. + * @cred_prepare: + * @new points to the new credentials. + * @old points to the original credentials. + * @gfp indicates the atomicity of any memory allocations. + * Prepare a new set of credentials by copying the data from the old set. + * @cred_commit: + * @new points to the new credentials. + * @old points to the original credentials. + * Install a new set of credentials. * @task_setuid: * Check permission before setting one or more of the user identity * attributes of the current process. The @flags parameter indicates @@ -614,15 +614,13 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @id2 contains a uid. * @flags contains one of the LSM_SETID_* values. * Return 0 if permission is granted. - * @task_post_setuid: + * @task_fix_setuid: * Update the module's state after setting one or more of the user * identity attributes of the current process. The @flags parameter * indicates which of the set*uid system calls invoked this hook. If - * @flags is LSM_SETID_FS, then @old_ruid is the old fs uid and the other - * parameters are not used. - * @old_ruid contains the old real uid (or fs uid if LSM_SETID_FS). - * @old_euid contains the old effective uid (or -1 if LSM_SETID_FS). - * @old_suid contains the old saved uid (or -1 if LSM_SETID_FS). + * @new is the set of credentials that will be installed. Modifications + * should be made to this rather than to @current->cred. + * @old is the set of credentials that are being replaces * @flags contains one of the LSM_SETID_* values. * Return 0 on success. * @task_setgid: @@ -725,13 +723,8 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @arg3 contains a argument. * @arg4 contains a argument. * @arg5 contains a argument. - * @rc_p contains a pointer to communicate back the forced return code - * Return 0 if permission is granted, and non-zero if the security module - * has taken responsibility (setting *rc_p) for the prctl call. - * @task_reparent_to_init: - * Set the security attributes in @p->security for a kernel thread that - * is being reparented to the init task. - * @p contains the task_struct for the kernel thread. + * Return -ENOSYS if no-one wanted to handle this op, any other value to + * cause prctl() to return immediately with that value. * @task_to_inode: * Set the security attributes for an inode based on an associated task's * security attributes, e.g. for /proc/pid inodes. @@ -1008,7 +1001,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * See whether a specific operational right is granted to a process on a * key. * @key_ref refers to the key (key pointer + possession attribute bit). - * @context points to the process to provide the context against which to + * @cred points to the credentials to provide the context against which to * evaluate the security data on the key. * @perm describes the combination of permissions required of this key. * Return 1 if permission granted, 0 if permission denied and -ve it the @@ -1170,6 +1163,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @child process. * Security modules may also want to perform a process tracing check * during an execve in the set_security or apply_creds hooks of + * tracing check during an execve in the bprm_set_creds hook of * binprm_security_ops if the process is being traced and its security * attributes would be changed by the execve. * @child contains the task_struct structure for the target process. @@ -1193,19 +1187,15 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @inheritable contains the inheritable capability set. * @permitted contains the permitted capability set. * Return 0 if the capability sets were successfully obtained. - * @capset_check: - * Check permission before setting the @effective, @inheritable, and - * @permitted capability sets for the current process. - * @effective contains the effective capability set. - * @inheritable contains the inheritable capability set. - * @permitted contains the permitted capability set. - * Return 0 if permission is granted. - * @capset_set: + * @capset: * Set the @effective, @inheritable, and @permitted capability sets for * the current process. + * @new contains the new credentials structure for target process. + * @old contains the current credentials structure for target process. * @effective contains the effective capability set. * @inheritable contains the inheritable capability set. * @permitted contains the permitted capability set. + * Return 0 and update @new if permission is granted. * @capable: * Check whether the @tsk process has the @cap capability. * @tsk contains the task_struct for the process. @@ -1297,12 +1287,11 @@ struct security_operations { int (*capget) (struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); - int (*capset_check) (const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted); - void (*capset_set) (const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted); + int (*capset) (struct cred *new, + const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted); int (*capable) (struct task_struct *tsk, int cap, int audit); int (*acct) (struct file *file); int (*sysctl) (struct ctl_table *table, int op); @@ -1314,7 +1303,7 @@ struct security_operations { int (*bprm_alloc_security) (struct linux_binprm *bprm); void (*bprm_free_security) (struct linux_binprm *bprm); - void (*bprm_apply_creds) (struct linux_binprm *bprm, int unsafe); + int (*bprm_apply_creds) (struct linux_binprm *bprm, int unsafe); void (*bprm_post_apply_creds) (struct linux_binprm *bprm); int (*bprm_set_security) (struct linux_binprm *bprm); int (*bprm_check_security) (struct linux_binprm *bprm); @@ -1405,11 +1394,13 @@ struct security_operations { int (*dentry_open) (struct file *file, const struct cred *cred); int (*task_create) (unsigned long clone_flags); - int (*cred_alloc_security) (struct cred *cred); void (*cred_free) (struct cred *cred); + int (*cred_prepare)(struct cred *new, const struct cred *old, + gfp_t gfp); + void (*cred_commit)(struct cred *new, const struct cred *old); int (*task_setuid) (uid_t id0, uid_t id1, uid_t id2, int flags); - int (*task_post_setuid) (uid_t old_ruid /* or fsuid */ , - uid_t old_euid, uid_t old_suid, int flags); + int (*task_fix_setuid) (struct cred *new, const struct cred *old, + int flags); int (*task_setgid) (gid_t id0, gid_t id1, gid_t id2, int flags); int (*task_setpgid) (struct task_struct *p, pid_t pgid); int (*task_getpgid) (struct task_struct *p); @@ -1429,8 +1420,7 @@ struct security_operations { int (*task_wait) (struct task_struct *p); int (*task_prctl) (int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, - unsigned long arg5, long *rc_p); - void (*task_reparent_to_init) (struct task_struct *p); + unsigned long arg5); void (*task_to_inode) (struct task_struct *p, struct inode *inode); int (*ipc_permission) (struct kern_ipc_perm *ipcp, short flag); @@ -1535,10 +1525,10 @@ struct security_operations { /* key management security hooks */ #ifdef CONFIG_KEYS - int (*key_alloc) (struct key *key, struct task_struct *tsk, unsigned long flags); + int (*key_alloc) (struct key *key, const struct cred *cred, unsigned long flags); void (*key_free) (struct key *key); int (*key_permission) (key_ref_t key_ref, - struct task_struct *context, + const struct cred *cred, key_perm_t perm); int (*key_getsecurity)(struct key *key, char **_buffer); #endif /* CONFIG_KEYS */ @@ -1564,12 +1554,10 @@ int security_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); -int security_capset_check(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted); -void security_capset_set(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted); +int security_capset(struct cred *new, const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted); int security_capable(struct task_struct *tsk, int cap); int security_capable_noaudit(struct task_struct *tsk, int cap); int security_acct(struct file *file); @@ -1583,7 +1571,7 @@ int security_vm_enough_memory_mm(struct mm_struct *mm, long pages); int security_vm_enough_memory_kern(long pages); int security_bprm_alloc(struct linux_binprm *bprm); void security_bprm_free(struct linux_binprm *bprm); -void security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe); +int security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe); void security_bprm_post_apply_creds(struct linux_binprm *bprm); int security_bprm_set(struct linux_binprm *bprm); int security_bprm_check(struct linux_binprm *bprm); @@ -1660,11 +1648,12 @@ int security_file_send_sigiotask(struct task_struct *tsk, int security_file_receive(struct file *file); int security_dentry_open(struct file *file, const struct cred *cred); int security_task_create(unsigned long clone_flags); -int security_cred_alloc(struct cred *cred); void security_cred_free(struct cred *cred); +int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); +void security_commit_creds(struct cred *new, const struct cred *old); int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags); -int security_task_post_setuid(uid_t old_ruid, uid_t old_euid, - uid_t old_suid, int flags); +int security_task_fix_setuid(struct cred *new, const struct cred *old, + int flags); int security_task_setgid(gid_t id0, gid_t id1, gid_t id2, int flags); int security_task_setpgid(struct task_struct *p, pid_t pgid); int security_task_getpgid(struct task_struct *p); @@ -1683,8 +1672,7 @@ int security_task_kill(struct task_struct *p, struct siginfo *info, int sig, u32 secid); int security_task_wait(struct task_struct *p); int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, - unsigned long arg4, unsigned long arg5, long *rc_p); -void security_task_reparent_to_init(struct task_struct *p); + unsigned long arg4, unsigned long arg5); void security_task_to_inode(struct task_struct *p, struct inode *inode); int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag); void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid); @@ -1759,18 +1747,13 @@ static inline int security_capget(struct task_struct *target, return cap_capget(target, effective, inheritable, permitted); } -static inline int security_capset_check(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted) +static inline int security_capset(struct cred *new, + const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { - return cap_capset_check(effective, inheritable, permitted); -} - -static inline void security_capset_set(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted) -{ - cap_capset_set(effective, inheritable, permitted); + return cap_capset(new, old, effective, inheritable, permitted); } static inline int security_capable(struct task_struct *tsk, int cap) @@ -1837,9 +1820,9 @@ static inline int security_bprm_alloc(struct linux_binprm *bprm) static inline void security_bprm_free(struct linux_binprm *bprm) { } -static inline void security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) +static inline int security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) { - cap_bprm_apply_creds(bprm, unsafe); + return cap_bprm_apply_creds(bprm, unsafe); } static inline void security_bprm_post_apply_creds(struct linux_binprm *bprm) @@ -2182,13 +2165,20 @@ static inline int security_task_create(unsigned long clone_flags) return 0; } -static inline int security_cred_alloc(struct cred *cred) +static inline void security_cred_free(struct cred *cred) +{ } + +static inline int security_prepare_creds(struct cred *new, + const struct cred *old, + gfp_t gfp) { return 0; } -static inline void security_cred_free(struct cred *cred) -{ } +static inline void security_commit_creds(struct cred *new, + const struct cred *old) +{ +} static inline int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) @@ -2196,10 +2186,11 @@ static inline int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, return 0; } -static inline int security_task_post_setuid(uid_t old_ruid, uid_t old_euid, - uid_t old_suid, int flags) +static inline int security_task_fix_setuid(struct cred *new, + const struct cred *old, + int flags) { - return cap_task_post_setuid(old_ruid, old_euid, old_suid, flags); + return cap_task_fix_setuid(new, old, flags); } static inline int security_task_setgid(gid_t id0, gid_t id1, gid_t id2, @@ -2286,14 +2277,9 @@ static inline int security_task_wait(struct task_struct *p) static inline int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, - unsigned long arg5, long *rc_p) -{ - return cap_task_prctl(option, arg2, arg3, arg3, arg5, rc_p); -} - -static inline void security_task_reparent_to_init(struct task_struct *p) + unsigned long arg5) { - cap_task_reparent_to_init(p); + return cap_task_prctl(option, arg2, arg3, arg3, arg5); } static inline void security_task_to_inode(struct task_struct *p, struct inode *inode) @@ -2719,16 +2705,16 @@ static inline void security_skb_classify_flow(struct sk_buff *skb, struct flowi #ifdef CONFIG_KEYS #ifdef CONFIG_SECURITY -int security_key_alloc(struct key *key, struct task_struct *tsk, unsigned long flags); +int security_key_alloc(struct key *key, const struct cred *cred, unsigned long flags); void security_key_free(struct key *key); int security_key_permission(key_ref_t key_ref, - struct task_struct *context, key_perm_t perm); + const struct cred *cred, key_perm_t perm); int security_key_getsecurity(struct key *key, char **_buffer); #else static inline int security_key_alloc(struct key *key, - struct task_struct *tsk, + const struct cred *cred, unsigned long flags) { return 0; @@ -2739,7 +2725,7 @@ static inline void security_key_free(struct key *key) } static inline int security_key_permission(key_ref_t key_ref, - struct task_struct *context, + const struct cred *cred, key_perm_t perm) { return 0; diff --git a/init/main.c b/init/main.c index 7e117a231af1..db843bff5732 100644 --- a/init/main.c +++ b/init/main.c @@ -669,6 +669,7 @@ asmlinkage void __init start_kernel(void) efi_enter_virtual_mode(); #endif thread_info_cache_init(); + cred_init(); fork_init(num_physpages); proc_caches_init(); buffer_init(); diff --git a/kernel/auditsc.c b/kernel/auditsc.c index ae8ef88ade3f..bc1e2d854bf6 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2546,18 +2546,17 @@ int __audit_signal_info(int sig, struct task_struct *t) /** * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps - * @bprm pointer to the bprm being processed - * @caps the caps read from the disk + * @bprm: pointer to the bprm being processed + * @new: the proposed new credentials + * @old: the old credentials * * Simply check if the proc already has the caps given by the file and if not * store the priv escalation info for later auditing at the end of the syscall * - * this can fail and we don't care. See the note in audit.h for - * audit_log_bprm_fcaps() for my explaination.... - * * -Eric */ -void __audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_cap_t *pE) +int __audit_log_bprm_fcaps(struct linux_binprm *bprm, + const struct cred *new, const struct cred *old) { struct audit_aux_data_bprm_fcaps *ax; struct audit_context *context = current->audit_context; @@ -2566,7 +2565,7 @@ void __audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_ ax = kmalloc(sizeof(*ax), GFP_KERNEL); if (!ax) - return; + return -ENOMEM; ax->d.type = AUDIT_BPRM_FCAPS; ax->d.next = context->aux; @@ -2581,26 +2580,27 @@ void __audit_log_bprm_fcaps(struct linux_binprm *bprm, kernel_cap_t *pP, kernel_ ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT; - ax->old_pcap.permitted = *pP; - ax->old_pcap.inheritable = current->cred->cap_inheritable; - ax->old_pcap.effective = *pE; + ax->old_pcap.permitted = old->cap_permitted; + ax->old_pcap.inheritable = old->cap_inheritable; + ax->old_pcap.effective = old->cap_effective; - ax->new_pcap.permitted = current->cred->cap_permitted; - ax->new_pcap.inheritable = current->cred->cap_inheritable; - ax->new_pcap.effective = current->cred->cap_effective; + ax->new_pcap.permitted = new->cap_permitted; + ax->new_pcap.inheritable = new->cap_inheritable; + ax->new_pcap.effective = new->cap_effective; + return 0; } /** * __audit_log_capset - store information about the arguments to the capset syscall - * @pid target pid of the capset call - * @eff effective cap set - * @inh inheritible cap set - * @perm permited cap set + * @pid: target pid of the capset call + * @new: the new credentials + * @old: the old (current) credentials * * Record the aguments userspace sent to sys_capset for later printing by the * audit system if applicable */ -int __audit_log_capset(pid_t pid, kernel_cap_t *eff, kernel_cap_t *inh, kernel_cap_t *perm) +int __audit_log_capset(pid_t pid, + const struct cred *new, const struct cred *old) { struct audit_aux_data_capset *ax; struct audit_context *context = current->audit_context; @@ -2617,9 +2617,9 @@ int __audit_log_capset(pid_t pid, kernel_cap_t *eff, kernel_cap_t *inh, kernel_c context->aux = (void *)ax; ax->pid = pid; - ax->cap.effective = *eff; - ax->cap.inheritable = *eff; - ax->cap.permitted = *perm; + ax->cap.effective = new->cap_effective; + ax->cap.inheritable = new->cap_effective; + ax->cap.permitted = new->cap_permitted; return 0; } diff --git a/kernel/capability.c b/kernel/capability.c index a404b980b1bd..36b4b4daebec 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -15,12 +15,7 @@ #include #include #include - -/* - * This lock protects task->cap_* for all tasks including current. - * Locking rule: acquire this prior to tasklist_lock. - */ -static DEFINE_SPINLOCK(task_capability_lock); +#include "cred-internals.h" /* * Leveraged for setting/resetting capabilities @@ -128,12 +123,11 @@ static int cap_validate_magic(cap_user_header_t header, unsigned *tocopy) } /* - * If we have configured with filesystem capability support, then the - * only thing that can change the capabilities of the current process - * is the current process. As such, we can't be in this code at the - * same time as we are in the process of setting capabilities in this - * process. The net result is that we can limit our use of locks to - * when we are reading the caps of another process. + * The only thing that can change the capabilities of the current + * process is the current process. As such, we can't be in this code + * at the same time as we are in the process of setting capabilities + * in this process. The net result is that we can limit our use of + * locks to when we are reading the caps of another process. */ static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp, kernel_cap_t *pIp, kernel_cap_t *pPp) @@ -143,7 +137,6 @@ static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp, if (pid && (pid != task_pid_vnr(current))) { struct task_struct *target; - spin_lock(&task_capability_lock); read_lock(&tasklist_lock); target = find_task_by_vpid(pid); @@ -153,34 +146,12 @@ static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp, ret = security_capget(target, pEp, pIp, pPp); read_unlock(&tasklist_lock); - spin_unlock(&task_capability_lock); } else ret = security_capget(current, pEp, pIp, pPp); return ret; } -/* - * Atomically modify the effective capabilities returning the original - * value. No permission check is performed here - it is assumed that the - * caller is permitted to set the desired effective capabilities. - */ -kernel_cap_t cap_set_effective(const kernel_cap_t pE_new) -{ - kernel_cap_t pE_old; - - spin_lock(&task_capability_lock); - - pE_old = current->cred->cap_effective; - current->cred->cap_effective = pE_new; - - spin_unlock(&task_capability_lock); - - return pE_old; -} - -EXPORT_SYMBOL(cap_set_effective); - /** * sys_capget - get the capabilities of a given process. * @header: pointer to struct that contains capability version and @@ -208,7 +179,6 @@ asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr) return -EINVAL; ret = cap_get_target_pid(pid, &pE, &pI, &pP); - if (!ret) { struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S]; unsigned i; @@ -270,6 +240,7 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S]; unsigned i, tocopy; kernel_cap_t inheritable, permitted, effective; + struct cred *new; int ret; pid_t pid; @@ -284,8 +255,8 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) if (pid != 0 && pid != task_pid_vnr(current)) return -EPERM; - if (copy_from_user(&kdata, data, tocopy - * sizeof(struct __user_cap_data_struct))) + if (copy_from_user(&kdata, data, + tocopy * sizeof(struct __user_cap_data_struct))) return -EFAULT; for (i = 0; i < tocopy; i++) { @@ -300,24 +271,23 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) i++; } - ret = audit_log_capset(pid, &effective, &inheritable, &permitted); - if (ret) + new = prepare_creds(); + if (!new) + return -ENOMEM; + + ret = security_capset(new, current_cred(), + &effective, &inheritable, &permitted); + if (ret < 0) + goto error; + + ret = audit_log_capset(pid, new, current_cred()); + if (ret < 0) return ret; - /* This lock is required even when filesystem capability support is - * configured - it protects the sys_capget() call from returning - * incorrect data in the case that the targeted process is not the - * current one. - */ - spin_lock(&task_capability_lock); - - ret = security_capset_check(&effective, &inheritable, &permitted); - /* Having verified that the proposed changes are legal, we now put them - * into effect. - */ - if (!ret) - security_capset_set(&effective, &inheritable, &permitted); - spin_unlock(&task_capability_lock); + return commit_creds(new); + +error: + abort_creds(new); return ret; } diff --git a/kernel/cred-internals.h b/kernel/cred-internals.h new file mode 100644 index 000000000000..2dc4fc2d0bf1 --- /dev/null +++ b/kernel/cred-internals.h @@ -0,0 +1,21 @@ +/* Internal credentials stuff + * + * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +/* + * user.c + */ +static inline void sched_switch_user(struct task_struct *p) +{ +#ifdef CONFIG_USER_SCHED + sched_move_task(p); +#endif /* CONFIG_USER_SCHED */ +} + diff --git a/kernel/cred.c b/kernel/cred.c index ac73e3617684..cb6b5eda978d 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -15,6 +15,10 @@ #include #include #include +#include +#include "cred-internals.h" + +static struct kmem_cache *cred_jar; /* * The common credentials for the initial task's thread group @@ -64,7 +68,7 @@ static void release_tgcred_rcu(struct rcu_head *rcu) /* * Release a set of thread group credentials. */ -static void release_tgcred(struct cred *cred) +void release_tgcred(struct cred *cred) { #ifdef CONFIG_KEYS struct thread_group_cred *tgcred = cred->tgcred; @@ -81,79 +85,322 @@ static void put_cred_rcu(struct rcu_head *rcu) { struct cred *cred = container_of(rcu, struct cred, rcu); - BUG_ON(atomic_read(&cred->usage) != 0); + if (atomic_read(&cred->usage) != 0) + panic("CRED: put_cred_rcu() sees %p with usage %d\n", + cred, atomic_read(&cred->usage)); + security_cred_free(cred); key_put(cred->thread_keyring); key_put(cred->request_key_auth); release_tgcred(cred); put_group_info(cred->group_info); free_uid(cred->user); - security_cred_free(cred); - kfree(cred); + kmem_cache_free(cred_jar, cred); } /** * __put_cred - Destroy a set of credentials - * @sec: The record to release + * @cred: The record to release * * Destroy a set of credentials on which no references remain. */ void __put_cred(struct cred *cred) { + BUG_ON(atomic_read(&cred->usage) != 0); + call_rcu(&cred->rcu, put_cred_rcu); } EXPORT_SYMBOL(__put_cred); +/** + * prepare_creds - Prepare a new set of credentials for modification + * + * Prepare a new set of task credentials for modification. A task's creds + * shouldn't generally be modified directly, therefore this function is used to + * prepare a new copy, which the caller then modifies and then commits by + * calling commit_creds(). + * + * Returns a pointer to the new creds-to-be if successful, NULL otherwise. + * + * Call commit_creds() or abort_creds() to clean up. + */ +struct cred *prepare_creds(void) +{ + struct task_struct *task = current; + const struct cred *old; + struct cred *new; + + BUG_ON(atomic_read(&task->cred->usage) < 1); + + new = kmem_cache_alloc(cred_jar, GFP_KERNEL); + if (!new) + return NULL; + + old = task->cred; + memcpy(new, old, sizeof(struct cred)); + + atomic_set(&new->usage, 1); + get_group_info(new->group_info); + get_uid(new->user); + +#ifdef CONFIG_KEYS + key_get(new->thread_keyring); + key_get(new->request_key_auth); + atomic_inc(&new->tgcred->usage); +#endif + +#ifdef CONFIG_SECURITY + new->security = NULL; +#endif + + if (security_prepare_creds(new, old, GFP_KERNEL) < 0) + goto error; + return new; + +error: + abort_creds(new); + return NULL; +} +EXPORT_SYMBOL(prepare_creds); + +/* + * prepare new credentials for the usermode helper dispatcher + */ +struct cred *prepare_usermodehelper_creds(void) +{ +#ifdef CONFIG_KEYS + struct thread_group_cred *tgcred = NULL; +#endif + struct cred *new; + +#ifdef CONFIG_KEYS + tgcred = kzalloc(sizeof(*new->tgcred), GFP_ATOMIC); + if (!tgcred) + return NULL; +#endif + + new = kmem_cache_alloc(cred_jar, GFP_ATOMIC); + if (!new) + return NULL; + + memcpy(new, &init_cred, sizeof(struct cred)); + + atomic_set(&new->usage, 1); + get_group_info(new->group_info); + get_uid(new->user); + +#ifdef CONFIG_KEYS + new->thread_keyring = NULL; + new->request_key_auth = NULL; + new->jit_keyring = KEY_REQKEY_DEFL_DEFAULT; + + atomic_set(&tgcred->usage, 1); + spin_lock_init(&tgcred->lock); + new->tgcred = tgcred; +#endif + +#ifdef CONFIG_SECURITY + new->security = NULL; +#endif + if (security_prepare_creds(new, &init_cred, GFP_ATOMIC) < 0) + goto error; + + BUG_ON(atomic_read(&new->usage) != 1); + return new; + +error: + put_cred(new); + return NULL; +} + /* * Copy credentials for the new process created by fork() + * + * We share if we can, but under some circumstances we have to generate a new + * set. */ int copy_creds(struct task_struct *p, unsigned long clone_flags) { - struct cred *pcred; - int ret; +#ifdef CONFIG_KEYS + struct thread_group_cred *tgcred; +#endif + struct cred *new; + + mutex_init(&p->cred_exec_mutex); - pcred = kmemdup(p->cred, sizeof(*p->cred), GFP_KERNEL); - if (!pcred) + if ( +#ifdef CONFIG_KEYS + !p->cred->thread_keyring && +#endif + clone_flags & CLONE_THREAD + ) { + get_cred(p->cred); + atomic_inc(&p->cred->user->processes); + return 0; + } + + new = prepare_creds(); + if (!new) return -ENOMEM; #ifdef CONFIG_KEYS - if (clone_flags & CLONE_THREAD) { - atomic_inc(&pcred->tgcred->usage); - } else { - pcred->tgcred = kmalloc(sizeof(struct cred), GFP_KERNEL); - if (!pcred->tgcred) { - kfree(pcred); + /* new threads get their own thread keyrings if their parent already + * had one */ + if (new->thread_keyring) { + key_put(new->thread_keyring); + new->thread_keyring = NULL; + if (clone_flags & CLONE_THREAD) + install_thread_keyring_to_cred(new); + } + + /* we share the process and session keyrings between all the threads in + * a process - this is slightly icky as we violate COW credentials a + * bit */ + if (!(clone_flags & CLONE_THREAD)) { + tgcred = kmalloc(sizeof(*tgcred), GFP_KERNEL); + if (!tgcred) { + put_cred(new); return -ENOMEM; } - atomic_set(&pcred->tgcred->usage, 1); - spin_lock_init(&pcred->tgcred->lock); - pcred->tgcred->process_keyring = NULL; - pcred->tgcred->session_keyring = - key_get(p->cred->tgcred->session_keyring); + atomic_set(&tgcred->usage, 1); + spin_lock_init(&tgcred->lock); + tgcred->process_keyring = NULL; + tgcred->session_keyring = key_get(new->tgcred->session_keyring); + + release_tgcred(new); + new->tgcred = tgcred; } #endif -#ifdef CONFIG_SECURITY - pcred->security = NULL; -#endif + atomic_inc(&new->user->processes); + p->cred = new; + return 0; +} - ret = security_cred_alloc(pcred); - if (ret < 0) { - release_tgcred(pcred); - kfree(pcred); - return ret; +/** + * commit_creds - Install new credentials upon the current task + * @new: The credentials to be assigned + * + * Install a new set of credentials to the current task, using RCU to replace + * the old set. + * + * This function eats the caller's reference to the new credentials. + * + * Always returns 0 thus allowing this function to be tail-called at the end + * of, say, sys_setgid(). + */ +int commit_creds(struct cred *new) +{ + struct task_struct *task = current; + const struct cred *old; + + BUG_ON(atomic_read(&new->usage) < 1); + BUG_ON(atomic_read(&task->cred->usage) < 1); + + old = task->cred; + security_commit_creds(new, old); + + /* dumpability changes */ + if (old->euid != new->euid || + old->egid != new->egid || + old->fsuid != new->fsuid || + old->fsgid != new->fsgid || + !cap_issubset(new->cap_permitted, old->cap_permitted)) { + set_dumpable(task->mm, suid_dumpable); + task->pdeath_signal = 0; + smp_wmb(); } - atomic_set(&pcred->usage, 1); - get_group_info(pcred->group_info); - get_uid(pcred->user); - key_get(pcred->thread_keyring); - key_get(pcred->request_key_auth); + /* alter the thread keyring */ + if (new->fsuid != old->fsuid) + key_fsuid_changed(task); + if (new->fsgid != old->fsgid) + key_fsgid_changed(task); + + /* do it + * - What if a process setreuid()'s and this brings the + * new uid over his NPROC rlimit? We can check this now + * cheaply with the new uid cache, so if it matters + * we should be checking for it. -DaveM + */ + if (new->user != old->user) + atomic_inc(&new->user->processes); + rcu_assign_pointer(task->cred, new); + if (new->user != old->user) + atomic_dec(&old->user->processes); + + sched_switch_user(task); + + /* send notifications */ + if (new->uid != old->uid || + new->euid != old->euid || + new->suid != old->suid || + new->fsuid != old->fsuid) + proc_id_connector(task, PROC_EVENT_UID); - atomic_inc(&pcred->user->processes); + if (new->gid != old->gid || + new->egid != old->egid || + new->sgid != old->sgid || + new->fsgid != old->fsgid) + proc_id_connector(task, PROC_EVENT_GID); - /* RCU assignment is unneeded here as no-one can have accessed this - * pointer yet, barring us */ - p->cred = pcred; + put_cred(old); return 0; } +EXPORT_SYMBOL(commit_creds); + +/** + * abort_creds - Discard a set of credentials and unlock the current task + * @new: The credentials that were going to be applied + * + * Discard a set of credentials that were under construction and unlock the + * current task. + */ +void abort_creds(struct cred *new) +{ + BUG_ON(atomic_read(&new->usage) < 1); + put_cred(new); +} +EXPORT_SYMBOL(abort_creds); + +/** + * override_creds - Temporarily override the current process's credentials + * @new: The credentials to be assigned + * + * Install a set of temporary override credentials on the current process, + * returning the old set for later reversion. + */ +const struct cred *override_creds(const struct cred *new) +{ + const struct cred *old = current->cred; + + rcu_assign_pointer(current->cred, get_cred(new)); + return old; +} +EXPORT_SYMBOL(override_creds); + +/** + * revert_creds - Revert a temporary credentials override + * @old: The credentials to be restored + * + * Revert a temporary set of override credentials to an old set, discarding the + * override set. + */ +void revert_creds(const struct cred *old) +{ + const struct cred *override = current->cred; + + rcu_assign_pointer(current->cred, old); + put_cred(override); +} +EXPORT_SYMBOL(revert_creds); + +/* + * initialise the credentials stuff + */ +void __init cred_init(void) +{ + /* allocate a slab in which we can store credentials */ + cred_jar = kmem_cache_create("cred_jar", sizeof(struct cred), + 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); +} diff --git a/kernel/exit.c b/kernel/exit.c index bbc22530f2c1..c0711da15486 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -47,12 +47,14 @@ #include #include #include +#include #include #include #include #include #include +#include "cred-internals.h" static void exit_mm(struct task_struct * tsk); @@ -338,12 +340,12 @@ static void reparent_to_kthreadd(void) /* cpus_allowed? */ /* rt_priority? */ /* signals? */ - security_task_reparent_to_init(current); memcpy(current->signal->rlim, init_task.signal->rlim, sizeof(current->signal->rlim)); - atomic_inc(&(INIT_USER->__count)); + + atomic_inc(&init_cred.usage); + commit_creds(&init_cred); write_unlock_irq(&tasklist_lock); - switch_uid(INIT_USER); } void __set_special_pids(struct pid *pid) @@ -1085,7 +1087,6 @@ NORET_TYPE void do_exit(long code) check_stack_usage(); exit_thread(); cgroup_exit(tsk, 1); - exit_keys(tsk); if (group_dead && tsk->signal->leader) disassociate_ctty(1); diff --git a/kernel/fork.c b/kernel/fork.c index ded1972672a3..82a7948a664e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1084,10 +1084,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, goto bad_fork_cleanup_sighand; if ((retval = copy_mm(clone_flags, p))) goto bad_fork_cleanup_signal; - if ((retval = copy_keys(clone_flags, p))) - goto bad_fork_cleanup_mm; if ((retval = copy_namespaces(clone_flags, p))) - goto bad_fork_cleanup_keys; + goto bad_fork_cleanup_mm; if ((retval = copy_io(clone_flags, p))) goto bad_fork_cleanup_namespaces; retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs); @@ -1252,8 +1250,6 @@ bad_fork_cleanup_io: put_io_context(p->io_context); bad_fork_cleanup_namespaces: exit_task_namespaces(p); -bad_fork_cleanup_keys: - exit_keys(p); bad_fork_cleanup_mm: if (p->mm) mmput(p->mm); @@ -1281,6 +1277,7 @@ bad_fork_cleanup_cgroup: bad_fork_cleanup_put_domain: module_put(task_thread_info(p)->exec_domain->module); bad_fork_cleanup_count: + atomic_dec(&p->cred->user->processes); put_cred(p->cred); bad_fork_free: free_task(p); diff --git a/kernel/kmod.c b/kernel/kmod.c index f044f8f57703..b46dbb908669 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -118,10 +118,10 @@ EXPORT_SYMBOL(request_module); struct subprocess_info { struct work_struct work; struct completion *complete; + struct cred *cred; char *path; char **argv; char **envp; - struct key *ring; enum umh_wait wait; int retval; struct file *stdin; @@ -134,19 +134,20 @@ struct subprocess_info { static int ____call_usermodehelper(void *data) { struct subprocess_info *sub_info = data; - struct key *new_session, *old_session; int retval; - /* Unblock all signals and set the session keyring. */ - new_session = key_get(sub_info->ring); + BUG_ON(atomic_read(&sub_info->cred->usage) != 1); + + /* Unblock all signals */ spin_lock_irq(¤t->sighand->siglock); - old_session = __install_session_keyring(new_session); flush_signal_handlers(current, 1); sigemptyset(¤t->blocked); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - key_put(old_session); + /* Install the credentials */ + commit_creds(sub_info->cred); + sub_info->cred = NULL; /* Install input pipe when needed */ if (sub_info->stdin) { @@ -185,6 +186,8 @@ void call_usermodehelper_freeinfo(struct subprocess_info *info) { if (info->cleanup) (*info->cleanup)(info->argv, info->envp); + if (info->cred) + put_cred(info->cred); kfree(info); } EXPORT_SYMBOL(call_usermodehelper_freeinfo); @@ -240,6 +243,8 @@ static void __call_usermodehelper(struct work_struct *work) pid_t pid; enum umh_wait wait = sub_info->wait; + BUG_ON(atomic_read(&sub_info->cred->usage) != 1); + /* CLONE_VFORK: wait until the usermode helper has execve'd * successfully We need the data structures to stay around * until that is done. */ @@ -362,6 +367,9 @@ struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, sub_info->path = path; sub_info->argv = argv; sub_info->envp = envp; + sub_info->cred = prepare_usermodehelper_creds(); + if (!sub_info->cred) + return NULL; out: return sub_info; @@ -376,7 +384,13 @@ EXPORT_SYMBOL(call_usermodehelper_setup); void call_usermodehelper_setkeys(struct subprocess_info *info, struct key *session_keyring) { - info->ring = session_keyring; +#ifdef CONFIG_KEYS + struct thread_group_cred *tgcred = info->cred->tgcred; + key_put(tgcred->session_keyring); + tgcred->session_keyring = key_get(session_keyring); +#else + BUG(); +#endif } EXPORT_SYMBOL(call_usermodehelper_setkeys); @@ -444,6 +458,8 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info, DECLARE_COMPLETION_ONSTACK(done); int retval = 0; + BUG_ON(atomic_read(&sub_info->cred->usage) != 1); + helper_lock(); if (sub_info->path[0] == '\0') goto out; diff --git a/kernel/ptrace.c b/kernel/ptrace.c index b9d5f4e4f6a4..f764b8806955 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -171,6 +171,14 @@ int ptrace_attach(struct task_struct *task) if (same_thread_group(task, current)) goto out; + /* Protect exec's credential calculations against our interference; + * SUID, SGID and LSM creds get determined differently under ptrace. + */ + retval = mutex_lock_interruptible(¤t->cred_exec_mutex); + if (retval < 0) + goto out; + + retval = -EPERM; repeat: /* * Nasty, nasty. @@ -210,6 +218,7 @@ repeat: bad: write_unlock_irqrestore(&tasklist_lock, flags); task_unlock(task); + mutex_unlock(¤t->cred_exec_mutex); out: return retval; } diff --git a/kernel/signal.c b/kernel/signal.c index 84989124bafb..2a64304ed54b 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -180,7 +180,7 @@ int next_signal(struct sigpending *pending, sigset_t *mask) /* * allocate a new signal queue record * - this may be called without locks if and only if t == current, otherwise an - * appopriate lock must be held to protect t's user_struct + * appopriate lock must be held to stop the target task from exiting */ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, int override_rlimit) @@ -194,7 +194,7 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, * caller must be holding the RCU readlock (by way of a spinlock) and * we use RCU protection here */ - user = __task_cred(t)->user; + user = get_uid(__task_cred(t)->user); atomic_inc(&user->sigpending); if (override_rlimit || atomic_read(&user->sigpending) <= @@ -202,12 +202,14 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, q = kmem_cache_alloc(sigqueue_cachep, flags); if (unlikely(q == NULL)) { atomic_dec(&user->sigpending); + free_uid(user); } else { INIT_LIST_HEAD(&q->list); q->flags = 0; - q->user = get_uid(user); + q->user = user; } - return(q); + + return q; } static void __sigqueue_free(struct sigqueue *q) diff --git a/kernel/sys.c b/kernel/sys.c index ccc9eb736d35..ab735040468a 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -180,7 +180,7 @@ asmlinkage long sys_setpriority(int which, int who, int niceval) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: - user = cred->user; + user = (struct user_struct *) cred->user; if (!who) who = cred->uid; else if ((who != cred->uid) && @@ -479,47 +479,48 @@ void ctrl_alt_del(void) */ asmlinkage long sys_setregid(gid_t rgid, gid_t egid) { - struct cred *cred = current->cred; - int old_rgid = cred->gid; - int old_egid = cred->egid; - int new_rgid = old_rgid; - int new_egid = old_egid; + const struct cred *old; + struct cred *new; int retval; + new = prepare_creds(); + if (!new) + return -ENOMEM; + old = current_cred(); + retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE); if (retval) - return retval; + goto error; + retval = -EPERM; if (rgid != (gid_t) -1) { - if ((old_rgid == rgid) || - (cred->egid == rgid) || + if (old->gid == rgid || + old->egid == rgid || capable(CAP_SETGID)) - new_rgid = rgid; + new->gid = rgid; else - return -EPERM; + goto error; } if (egid != (gid_t) -1) { - if ((old_rgid == egid) || - (cred->egid == egid) || - (cred->sgid == egid) || + if (old->gid == egid || + old->egid == egid || + old->sgid == egid || capable(CAP_SETGID)) - new_egid = egid; + new->egid = egid; else - return -EPERM; - } - if (new_egid != old_egid) { - set_dumpable(current->mm, suid_dumpable); - smp_wmb(); + goto error; } + if (rgid != (gid_t) -1 || - (egid != (gid_t) -1 && egid != old_rgid)) - cred->sgid = new_egid; - cred->fsgid = new_egid; - cred->egid = new_egid; - cred->gid = new_rgid; - key_fsgid_changed(current); - proc_id_connector(current, PROC_EVENT_GID); - return 0; + (egid != (gid_t) -1 && egid != old->gid)) + new->sgid = new->egid; + new->fsgid = new->egid; + + return commit_creds(new); + +error: + abort_creds(new); + return retval; } /* @@ -529,40 +530,42 @@ asmlinkage long sys_setregid(gid_t rgid, gid_t egid) */ asmlinkage long sys_setgid(gid_t gid) { - struct cred *cred = current->cred; - int old_egid = cred->egid; + const struct cred *old; + struct cred *new; int retval; + new = prepare_creds(); + if (!new) + return -ENOMEM; + old = current_cred(); + retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); if (retval) - return retval; + goto error; - if (capable(CAP_SETGID)) { - if (old_egid != gid) { - set_dumpable(current->mm, suid_dumpable); - smp_wmb(); - } - cred->gid = cred->egid = cred->sgid = cred->fsgid = gid; - } else if ((gid == cred->gid) || (gid == cred->sgid)) { - if (old_egid != gid) { - set_dumpable(current->mm, suid_dumpable); - smp_wmb(); - } - cred->egid = cred->fsgid = gid; - } + retval = -EPERM; + if (capable(CAP_SETGID)) + new->gid = new->egid = new->sgid = new->fsgid = gid; + else if (gid == old->gid || gid == old->sgid) + new->egid = new->fsgid = gid; else - return -EPERM; + goto error; - key_fsgid_changed(current); - proc_id_connector(current, PROC_EVENT_GID); - return 0; + return commit_creds(new); + +error: + abort_creds(new); + return retval; } -static int set_user(uid_t new_ruid, int dumpclear) +/* + * change the user struct in a credentials set to match the new UID + */ +static int set_user(struct cred *new) { struct user_struct *new_user; - new_user = alloc_uid(current->nsproxy->user_ns, new_ruid); + new_user = alloc_uid(current->nsproxy->user_ns, new->uid); if (!new_user) return -EAGAIN; @@ -573,13 +576,8 @@ static int set_user(uid_t new_ruid, int dumpclear) return -EAGAIN; } - switch_uid(new_user); - - if (dumpclear) { - set_dumpable(current->mm, suid_dumpable); - smp_wmb(); - } - current->cred->uid = new_ruid; + free_uid(new->user); + new->user = new_user; return 0; } @@ -600,55 +598,56 @@ static int set_user(uid_t new_ruid, int dumpclear) */ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) { - struct cred *cred = current->cred; - int old_ruid, old_euid, old_suid, new_ruid, new_euid; + const struct cred *old; + struct cred *new; int retval; + new = prepare_creds(); + if (!new) + return -ENOMEM; + old = current_cred(); + retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE); if (retval) - return retval; - - new_ruid = old_ruid = cred->uid; - new_euid = old_euid = cred->euid; - old_suid = cred->suid; + goto error; + retval = -EPERM; if (ruid != (uid_t) -1) { - new_ruid = ruid; - if ((old_ruid != ruid) && - (cred->euid != ruid) && + new->uid = ruid; + if (old->uid != ruid && + old->euid != ruid && !capable(CAP_SETUID)) - return -EPERM; + goto error; } if (euid != (uid_t) -1) { - new_euid = euid; - if ((old_ruid != euid) && - (cred->euid != euid) && - (cred->suid != euid) && + new->euid = euid; + if (old->uid != euid && + old->euid != euid && + old->suid != euid && !capable(CAP_SETUID)) - return -EPERM; + goto error; } - if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0) - return -EAGAIN; + retval = -EAGAIN; + if (new->uid != old->uid && set_user(new) < 0) + goto error; - if (new_euid != old_euid) { - set_dumpable(current->mm, suid_dumpable); - smp_wmb(); - } - cred->fsuid = cred->euid = new_euid; if (ruid != (uid_t) -1 || - (euid != (uid_t) -1 && euid != old_ruid)) - cred->suid = cred->euid; - cred->fsuid = cred->euid; - - key_fsuid_changed(current); - proc_id_connector(current, PROC_EVENT_UID); + (euid != (uid_t) -1 && euid != old->uid)) + new->suid = new->euid; + new->fsuid = new->euid; - return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE); -} + retval = security_task_fix_setuid(new, old, LSM_SETID_RE); + if (retval < 0) + goto error; + return commit_creds(new); +error: + abort_creds(new); + return retval; +} /* * setuid() is implemented like SysV with SAVED_IDS @@ -663,37 +662,41 @@ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) */ asmlinkage long sys_setuid(uid_t uid) { - struct cred *cred = current->cred; - int old_euid = cred->euid; - int old_ruid, old_suid, new_suid; + const struct cred *old; + struct cred *new; int retval; + new = prepare_creds(); + if (!new) + return -ENOMEM; + old = current_cred(); + retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID); if (retval) - return retval; + goto error; - old_ruid = cred->uid; - old_suid = cred->suid; - new_suid = old_suid; - + retval = -EPERM; if (capable(CAP_SETUID)) { - if (uid != old_ruid && set_user(uid, old_euid != uid) < 0) - return -EAGAIN; - new_suid = uid; - } else if ((uid != cred->uid) && (uid != new_suid)) - return -EPERM; - - if (old_euid != uid) { - set_dumpable(current->mm, suid_dumpable); - smp_wmb(); + new->suid = new->uid = uid; + if (uid != old->uid && set_user(new) < 0) { + retval = -EAGAIN; + goto error; + } + } else if (uid != old->uid && uid != new->suid) { + goto error; } - cred->fsuid = cred->euid = uid; - cred->suid = new_suid; - key_fsuid_changed(current); - proc_id_connector(current, PROC_EVENT_UID); + new->fsuid = new->euid = uid; + + retval = security_task_fix_setuid(new, old, LSM_SETID_ID); + if (retval < 0) + goto error; + + return commit_creds(new); - return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID); +error: + abort_creds(new); + return retval; } @@ -703,47 +706,53 @@ asmlinkage long sys_setuid(uid_t uid) */ asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) { - struct cred *cred = current->cred; - int old_ruid = cred->uid; - int old_euid = cred->euid; - int old_suid = cred->suid; + const struct cred *old; + struct cred *new; int retval; + new = prepare_creds(); + if (!new) + return -ENOMEM; + retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES); if (retval) - return retval; + goto error; + old = current_cred(); + retval = -EPERM; if (!capable(CAP_SETUID)) { - if ((ruid != (uid_t) -1) && (ruid != cred->uid) && - (ruid != cred->euid) && (ruid != cred->suid)) - return -EPERM; - if ((euid != (uid_t) -1) && (euid != cred->uid) && - (euid != cred->euid) && (euid != cred->suid)) - return -EPERM; - if ((suid != (uid_t) -1) && (suid != cred->uid) && - (suid != cred->euid) && (suid != cred->suid)) - return -EPERM; + if (ruid != (uid_t) -1 && ruid != old->uid && + ruid != old->euid && ruid != old->suid) + goto error; + if (euid != (uid_t) -1 && euid != old->uid && + euid != old->euid && euid != old->suid) + goto error; + if (suid != (uid_t) -1 && suid != old->uid && + suid != old->euid && suid != old->suid) + goto error; } + + retval = -EAGAIN; if (ruid != (uid_t) -1) { - if (ruid != cred->uid && - set_user(ruid, euid != cred->euid) < 0) - return -EAGAIN; + new->uid = ruid; + if (ruid != old->uid && set_user(new) < 0) + goto error; } - if (euid != (uid_t) -1) { - if (euid != cred->euid) { - set_dumpable(current->mm, suid_dumpable); - smp_wmb(); - } - cred->euid = euid; - } - cred->fsuid = cred->euid; + if (euid != (uid_t) -1) + new->euid = euid; if (suid != (uid_t) -1) - cred->suid = suid; + new->suid = suid; + new->fsuid = new->euid; - key_fsuid_changed(current); - proc_id_connector(current, PROC_EVENT_UID); + retval = security_task_fix_setuid(new, old, LSM_SETID_RES); + if (retval < 0) + goto error; - return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES); + return commit_creds(new); + +error: + abort_creds(new); + return retval; } asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid) @@ -763,40 +772,45 @@ asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __us */ asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) { - struct cred *cred = current->cred; + const struct cred *old; + struct cred *new; int retval; + new = prepare_creds(); + if (!new) + return -ENOMEM; + old = current_cred(); + retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES); if (retval) - return retval; + goto error; + retval = -EPERM; if (!capable(CAP_SETGID)) { - if ((rgid != (gid_t) -1) && (rgid != cred->gid) && - (rgid != cred->egid) && (rgid != cred->sgid)) - return -EPERM; - if ((egid != (gid_t) -1) && (egid != cred->gid) && - (egid != cred->egid) && (egid != cred->sgid)) - return -EPERM; - if ((sgid != (gid_t) -1) && (sgid != cred->gid) && - (sgid != cred->egid) && (sgid != cred->sgid)) - return -EPERM; + if (rgid != (gid_t) -1 && rgid != old->gid && + rgid != old->egid && rgid != old->sgid) + goto error; + if (egid != (gid_t) -1 && egid != old->gid && + egid != old->egid && egid != old->sgid) + goto error; + if (sgid != (gid_t) -1 && sgid != old->gid && + sgid != old->egid && sgid != old->sgid) + goto error; } - if (egid != (gid_t) -1) { - if (egid != cred->egid) { - set_dumpable(current->mm, suid_dumpable); - smp_wmb(); - } - cred->egid = egid; - } - cred->fsgid = cred->egid; + if (rgid != (gid_t) -1) - cred->gid = rgid; + new->gid = rgid; + if (egid != (gid_t) -1) + new->egid = egid; if (sgid != (gid_t) -1) - cred->sgid = sgid; + new->sgid = sgid; + new->fsgid = new->egid; - key_fsgid_changed(current); - proc_id_connector(current, PROC_EVENT_GID); - return 0; + return commit_creds(new); + +error: + abort_creds(new); + return retval; } asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid) @@ -820,28 +834,35 @@ asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __us */ asmlinkage long sys_setfsuid(uid_t uid) { - struct cred *cred = current->cred; - int old_fsuid; + const struct cred *old; + struct cred *new; + uid_t old_fsuid; + + new = prepare_creds(); + if (!new) + return current_fsuid(); + old = current_cred(); + old_fsuid = old->fsuid; - old_fsuid = cred->fsuid; - if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS)) - return old_fsuid; + if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS) < 0) + goto error; - if (uid == cred->uid || uid == cred->euid || - uid == cred->suid || uid == cred->fsuid || + if (uid == old->uid || uid == old->euid || + uid == old->suid || uid == old->fsuid || capable(CAP_SETUID)) { if (uid != old_fsuid) { - set_dumpable(current->mm, suid_dumpable); - smp_wmb(); + new->fsuid = uid; + if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) + goto change_okay; } - cred->fsuid = uid; } - key_fsuid_changed(current); - proc_id_connector(current, PROC_EVENT_UID); - - security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); +error: + abort_creds(new); + return old_fsuid; +change_okay: + commit_creds(new); return old_fsuid; } @@ -850,24 +871,34 @@ asmlinkage long sys_setfsuid(uid_t uid) */ asmlinkage long sys_setfsgid(gid_t gid) { - struct cred *cred = current->cred; - int old_fsgid; + const struct cred *old; + struct cred *new; + gid_t old_fsgid; + + new = prepare_creds(); + if (!new) + return current_fsgid(); + old = current_cred(); + old_fsgid = old->fsgid; - old_fsgid = cred->fsgid; if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS)) - return old_fsgid; + goto error; - if (gid == cred->gid || gid == cred->egid || - gid == cred->sgid || gid == cred->fsgid || + if (gid == old->gid || gid == old->egid || + gid == old->sgid || gid == old->fsgid || capable(CAP_SETGID)) { if (gid != old_fsgid) { - set_dumpable(current->mm, suid_dumpable); - smp_wmb(); + new->fsgid = gid; + goto change_okay; } - cred->fsgid = gid; - key_fsgid_changed(current); - proc_id_connector(current, PROC_EVENT_GID); } + +error: + abort_creds(new); + return old_fsgid; + +change_okay: + commit_creds(new); return old_fsgid; } @@ -1136,7 +1167,7 @@ EXPORT_SYMBOL(groups_free); /* export the group_info to a user-space array */ static int groups_to_user(gid_t __user *grouplist, - struct group_info *group_info) + const struct group_info *group_info) { int i; unsigned int count = group_info->ngroups; @@ -1227,31 +1258,25 @@ int groups_search(const struct group_info *group_info, gid_t grp) } /** - * set_groups - Change a group subscription in a security record - * @sec: The security record to alter - * @group_info: The group list to impose + * set_groups - Change a group subscription in a set of credentials + * @new: The newly prepared set of credentials to alter + * @group_info: The group list to install * - * Validate a group subscription and, if valid, impose it upon a task security - * record. + * Validate a group subscription and, if valid, insert it into a set + * of credentials. */ -int set_groups(struct cred *cred, struct group_info *group_info) +int set_groups(struct cred *new, struct group_info *group_info) { int retval; - struct group_info *old_info; retval = security_task_setgroups(group_info); if (retval) return retval; + put_group_info(new->group_info); groups_sort(group_info); get_group_info(group_info); - - spin_lock(&cred->lock); - old_info = cred->group_info; - cred->group_info = group_info; - spin_unlock(&cred->lock); - - put_group_info(old_info); + new->group_info = group_info; return 0; } @@ -1266,7 +1291,20 @@ EXPORT_SYMBOL(set_groups); */ int set_current_groups(struct group_info *group_info) { - return set_groups(current->cred, group_info); + struct cred *new; + int ret; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + ret = set_groups(new, group_info); + if (ret < 0) { + abort_creds(new); + return ret; + } + + return commit_creds(new); } EXPORT_SYMBOL(set_current_groups); @@ -1666,9 +1704,11 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned char comm[sizeof(me->comm)]; long error; - if (security_task_prctl(option, arg2, arg3, arg4, arg5, &error)) + error = security_task_prctl(option, arg2, arg3, arg4, arg5); + if (error != -ENOSYS) return error; + error = 0; switch (option) { case PR_SET_PDEATHSIG: if (!valid_signal(arg2)) { diff --git a/kernel/user.c b/kernel/user.c index 104d22ac84d5..d476307dd4b0 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -16,6 +16,7 @@ #include #include #include +#include "cred-internals.h" struct user_namespace init_user_ns = { .kref = { @@ -104,16 +105,10 @@ static int sched_create_user(struct user_struct *up) return rc; } -static void sched_switch_user(struct task_struct *p) -{ - sched_move_task(p); -} - #else /* CONFIG_USER_SCHED */ static void sched_destroy_user(struct user_struct *up) { } static int sched_create_user(struct user_struct *up) { return 0; } -static void sched_switch_user(struct task_struct *p) { } #endif /* CONFIG_USER_SCHED */ @@ -448,36 +443,6 @@ out_unlock: return NULL; } -void switch_uid(struct user_struct *new_user) -{ - struct user_struct *old_user; - - /* What if a process setreuid()'s and this brings the - * new uid over his NPROC rlimit? We can check this now - * cheaply with the new uid cache, so if it matters - * we should be checking for it. -DaveM - */ - old_user = current->cred->user; - atomic_inc(&new_user->processes); - atomic_dec(&old_user->processes); - switch_uid_keyring(new_user); - current->cred->user = new_user; - sched_switch_user(current); - - /* - * We need to synchronize with __sigqueue_alloc() - * doing a get_uid(p->user).. If that saw the old - * user value, we need to wait until it has exited - * its critical region before we can free the old - * structure. - */ - smp_mb(); - spin_unlock_wait(¤t->sighand->siglock); - - free_uid(old_user); - suid_keys(current); -} - #ifdef CONFIG_USER_NS void release_uids(struct user_namespace *ns) { diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index f82730adea00..0d9c51d67333 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -19,6 +19,7 @@ static struct user_namespace *clone_user_ns(struct user_namespace *old_ns) { struct user_namespace *ns; struct user_struct *new_user; + struct cred *new; int n; ns = kmalloc(sizeof(struct user_namespace), GFP_KERNEL); @@ -45,7 +46,16 @@ static struct user_namespace *clone_user_ns(struct user_namespace *old_ns) return ERR_PTR(-ENOMEM); } - switch_uid(new_user); + /* Install the new user */ + new = prepare_creds(); + if (!new) { + free_uid(new_user); + free_uid(ns->root_user); + kfree(ns); + } + free_uid(new->user); + new->user = new_user; + commit_creds(new); return ns; } diff --git a/lib/Makefile b/lib/Makefile index 7cb65d85aeb0..80fe8a3ec12a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -11,7 +11,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o dump_stack.o \ idr.o int_sqrt.o extable.o prio_tree.o \ sha1.o irq_regs.o reciprocal_div.o argv_split.o \ - proportions.o prio_heap.o ratelimit.o show_mem.o + proportions.o prio_heap.o ratelimit.o show_mem.o is_single_threaded.o lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c index 9a8ff684da79..ad8c7a782da1 100644 --- a/net/rxrpc/ar-key.c +++ b/net/rxrpc/ar-key.c @@ -287,6 +287,7 @@ int rxrpc_get_server_data_key(struct rxrpc_connection *conn, time_t expiry, u32 kvno) { + const struct cred *cred = current_cred(); struct key *key; int ret; @@ -297,7 +298,7 @@ int rxrpc_get_server_data_key(struct rxrpc_connection *conn, _enter(""); - key = key_alloc(&key_type_rxrpc, "x", 0, 0, current, 0, + key = key_alloc(&key_type_rxrpc, "x", 0, 0, cred, 0, KEY_ALLOC_NOT_IN_QUOTA); if (IS_ERR(key)) { _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key)); @@ -340,10 +341,11 @@ EXPORT_SYMBOL(rxrpc_get_server_data_key); */ struct key *rxrpc_get_null_key(const char *keyname) { + const struct cred *cred = current_cred(); struct key *key; int ret; - key = key_alloc(&key_type_rxrpc, keyname, 0, 0, current, + key = key_alloc(&key_type_rxrpc, keyname, 0, 0, cred, KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA); if (IS_ERR(key)) return key; diff --git a/security/capability.c b/security/capability.c index fac2f61b69a9..efeb6d9e0e6a 100644 --- a/security/capability.c +++ b/security/capability.c @@ -340,12 +340,16 @@ static int cap_task_create(unsigned long clone_flags) return 0; } -static int cap_cred_alloc_security(struct cred *cred) +static void cap_cred_free(struct cred *cred) +{ +} + +static int cap_cred_prepare(struct cred *new, const struct cred *old, gfp_t gfp) { return 0; } -static void cap_cred_free(struct cred *cred) +static void cap_cred_commit(struct cred *new, const struct cred *old) { } @@ -750,7 +754,7 @@ static void cap_release_secctx(char *secdata, u32 seclen) } #ifdef CONFIG_KEYS -static int cap_key_alloc(struct key *key, struct task_struct *ctx, +static int cap_key_alloc(struct key *key, const struct cred *cred, unsigned long flags) { return 0; @@ -760,7 +764,7 @@ static void cap_key_free(struct key *key) { } -static int cap_key_permission(key_ref_t key_ref, struct task_struct *context, +static int cap_key_permission(key_ref_t key_ref, const struct cred *cred, key_perm_t perm) { return 0; @@ -814,8 +818,7 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, ptrace_may_access); set_to_cap_if_null(ops, ptrace_traceme); set_to_cap_if_null(ops, capget); - set_to_cap_if_null(ops, capset_check); - set_to_cap_if_null(ops, capset_set); + set_to_cap_if_null(ops, capset); set_to_cap_if_null(ops, acct); set_to_cap_if_null(ops, capable); set_to_cap_if_null(ops, quotactl); @@ -890,10 +893,11 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, file_receive); set_to_cap_if_null(ops, dentry_open); set_to_cap_if_null(ops, task_create); - set_to_cap_if_null(ops, cred_alloc_security); set_to_cap_if_null(ops, cred_free); + set_to_cap_if_null(ops, cred_prepare); + set_to_cap_if_null(ops, cred_commit); set_to_cap_if_null(ops, task_setuid); - set_to_cap_if_null(ops, task_post_setuid); + set_to_cap_if_null(ops, task_fix_setuid); set_to_cap_if_null(ops, task_setgid); set_to_cap_if_null(ops, task_setpgid); set_to_cap_if_null(ops, task_getpgid); @@ -910,7 +914,6 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, task_wait); set_to_cap_if_null(ops, task_kill); set_to_cap_if_null(ops, task_prctl); - set_to_cap_if_null(ops, task_reparent_to_init); set_to_cap_if_null(ops, task_to_inode); set_to_cap_if_null(ops, ipc_permission); set_to_cap_if_null(ops, ipc_getsecid); diff --git a/security/commoncap.c b/security/commoncap.c index 0384bf95db68..b5419273f92d 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -72,8 +72,8 @@ int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) int ret = 0; rcu_read_lock(); - if (!cap_issubset(child->cred->cap_permitted, - current->cred->cap_permitted) && + if (!cap_issubset(__task_cred(child)->cap_permitted, + current_cred()->cap_permitted) && !capable(CAP_SYS_PTRACE)) ret = -EPERM; rcu_read_unlock(); @@ -85,8 +85,8 @@ int cap_ptrace_traceme(struct task_struct *parent) int ret = 0; rcu_read_lock(); - if (!cap_issubset(current->cred->cap_permitted, - parent->cred->cap_permitted) && + if (!cap_issubset(current_cred()->cap_permitted, + __task_cred(parent)->cap_permitted) && !has_capability(parent, CAP_SYS_PTRACE)) ret = -EPERM; rcu_read_unlock(); @@ -117,7 +117,7 @@ static inline int cap_inh_is_capped(void) * to the old permitted set. That is, if the current task * does *not* possess the CAP_SETPCAP capability. */ - return (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0); + return cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0; } static inline int cap_limit_ptraced_target(void) { return 1; } @@ -132,52 +132,39 @@ static inline int cap_limit_ptraced_target(void) #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ -int cap_capset_check(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted) +int cap_capset(struct cred *new, + const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { - const struct cred *cred = current->cred; - - if (cap_inh_is_capped() - && !cap_issubset(*inheritable, - cap_combine(cred->cap_inheritable, - cred->cap_permitted))) { + if (cap_inh_is_capped() && + !cap_issubset(*inheritable, + cap_combine(old->cap_inheritable, + old->cap_permitted))) /* incapable of using this inheritable set */ return -EPERM; - } + if (!cap_issubset(*inheritable, - cap_combine(cred->cap_inheritable, - cred->cap_bset))) { + cap_combine(old->cap_inheritable, + old->cap_bset))) /* no new pI capabilities outside bounding set */ return -EPERM; - } /* verify restrictions on target's new Permitted set */ - if (!cap_issubset (*permitted, - cap_combine (cred->cap_permitted, - cred->cap_permitted))) { + if (!cap_issubset(*permitted, old->cap_permitted)) return -EPERM; - } /* verify the _new_Effective_ is a subset of the _new_Permitted_ */ - if (!cap_issubset (*effective, *permitted)) { + if (!cap_issubset(*effective, *permitted)) return -EPERM; - } + new->cap_effective = *effective; + new->cap_inheritable = *inheritable; + new->cap_permitted = *permitted; return 0; } -void cap_capset_set(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted) -{ - struct cred *cred = current->cred; - - cred->cap_effective = *effective; - cred->cap_inheritable = *inheritable; - cred->cap_permitted = *permitted; -} - static inline void bprm_clear_caps(struct linux_binprm *bprm) { cap_clear(bprm->cap_post_exec_permitted); @@ -382,41 +369,46 @@ int cap_bprm_set_security (struct linux_binprm *bprm) return ret; } -void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) +int cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) { - struct cred *cred = current->cred; + const struct cred *old = current_cred(); + struct cred *new; + + new = prepare_creds(); + if (!new) + return -ENOMEM; - if (bprm->e_uid != cred->uid || bprm->e_gid != cred->gid || + if (bprm->e_uid != old->uid || bprm->e_gid != old->gid || !cap_issubset(bprm->cap_post_exec_permitted, - cred->cap_permitted)) { + old->cap_permitted)) { set_dumpable(current->mm, suid_dumpable); current->pdeath_signal = 0; if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) { if (!capable(CAP_SETUID)) { - bprm->e_uid = cred->uid; - bprm->e_gid = cred->gid; + bprm->e_uid = old->uid; + bprm->e_gid = old->gid; } if (cap_limit_ptraced_target()) { bprm->cap_post_exec_permitted = cap_intersect( bprm->cap_post_exec_permitted, - cred->cap_permitted); + new->cap_permitted); } } } - cred->suid = cred->euid = cred->fsuid = bprm->e_uid; - cred->sgid = cred->egid = cred->fsgid = bprm->e_gid; + new->suid = new->euid = new->fsuid = bprm->e_uid; + new->sgid = new->egid = new->fsgid = bprm->e_gid; /* For init, we want to retain the capabilities set * in the init_task struct. Thus we skip the usual * capability rules */ if (!is_global_init(current)) { - cred->cap_permitted = bprm->cap_post_exec_permitted; + new->cap_permitted = bprm->cap_post_exec_permitted; if (bprm->cap_effective) - cred->cap_effective = bprm->cap_post_exec_permitted; + new->cap_effective = bprm->cap_post_exec_permitted; else - cap_clear(cred->cap_effective); + cap_clear(new->cap_effective); } /* @@ -431,15 +423,15 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) * Number 1 above might fail if you don't have a full bset, but I think * that is interesting information to audit. */ - if (!cap_isclear(cred->cap_effective)) { - if (!cap_issubset(CAP_FULL_SET, cred->cap_effective) || - (bprm->e_uid != 0) || (cred->uid != 0) || + if (!cap_isclear(new->cap_effective)) { + if (!cap_issubset(CAP_FULL_SET, new->cap_effective) || + bprm->e_uid != 0 || new->uid != 0 || issecure(SECURE_NOROOT)) - audit_log_bprm_fcaps(bprm, &cred->cap_permitted, - &cred->cap_effective); + audit_log_bprm_fcaps(bprm, new, old); } - cred->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); + new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); + return commit_creds(new); } int cap_bprm_secureexec (struct linux_binprm *bprm) @@ -514,65 +506,49 @@ int cap_inode_removexattr(struct dentry *dentry, const char *name) * files.. * Thanks to Olaf Kirch and Peter Benie for spotting this. */ -static inline void cap_emulate_setxuid (int old_ruid, int old_euid, - int old_suid) +static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old) { - struct cred *cred = current->cred; - - if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) && - (cred->uid != 0 && cred->euid != 0 && cred->suid != 0) && + if ((old->uid == 0 || old->euid == 0 || old->suid == 0) && + (new->uid != 0 && new->euid != 0 && new->suid != 0) && !issecure(SECURE_KEEP_CAPS)) { - cap_clear(cred->cap_permitted); - cap_clear(cred->cap_effective); - } - if (old_euid == 0 && cred->euid != 0) { - cap_clear(cred->cap_effective); - } - if (old_euid != 0 && cred->euid == 0) { - cred->cap_effective = cred->cap_permitted; + cap_clear(new->cap_permitted); + cap_clear(new->cap_effective); } + if (old->euid == 0 && new->euid != 0) + cap_clear(new->cap_effective); + if (old->euid != 0 && new->euid == 0) + new->cap_effective = new->cap_permitted; } -int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, - int flags) +int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags) { - struct cred *cred = current->cred; - switch (flags) { case LSM_SETID_RE: case LSM_SETID_ID: case LSM_SETID_RES: /* Copied from kernel/sys.c:setreuid/setuid/setresuid. */ - if (!issecure (SECURE_NO_SETUID_FIXUP)) { - cap_emulate_setxuid (old_ruid, old_euid, old_suid); - } + if (!issecure(SECURE_NO_SETUID_FIXUP)) + cap_emulate_setxuid(new, old); break; case LSM_SETID_FS: - { - uid_t old_fsuid = old_ruid; - - /* Copied from kernel/sys.c:setfsuid. */ + /* Copied from kernel/sys.c:setfsuid. */ - /* - * FIXME - is fsuser used for all CAP_FS_MASK capabilities? - * if not, we might be a bit too harsh here. - */ - - if (!issecure (SECURE_NO_SETUID_FIXUP)) { - if (old_fsuid == 0 && cred->fsuid != 0) { - cred->cap_effective = - cap_drop_fs_set( - cred->cap_effective); - } - if (old_fsuid != 0 && cred->fsuid == 0) { - cred->cap_effective = - cap_raise_fs_set( - cred->cap_effective, - cred->cap_permitted); - } + /* + * FIXME - is fsuser used for all CAP_FS_MASK capabilities? + * if not, we might be a bit too harsh here. + */ + if (!issecure(SECURE_NO_SETUID_FIXUP)) { + if (old->fsuid == 0 && new->fsuid != 0) { + new->cap_effective = + cap_drop_fs_set(new->cap_effective); + } + if (old->fsuid != 0 && new->fsuid == 0) { + new->cap_effective = + cap_raise_fs_set(new->cap_effective, + new->cap_permitted); } - break; } + break; default: return -EINVAL; } @@ -628,13 +604,14 @@ int cap_task_setnice (struct task_struct *p, int nice) * this task could get inconsistent info. There can be no * racing writer bc a task can only change its own caps. */ -static long cap_prctl_drop(unsigned long cap) +static long cap_prctl_drop(struct cred *new, unsigned long cap) { if (!capable(CAP_SETPCAP)) return -EPERM; if (!cap_valid(cap)) return -EINVAL; - cap_lower(current->cred->cap_bset, cap); + + cap_lower(new->cap_bset, cap); return 0; } @@ -655,22 +632,29 @@ int cap_task_setnice (struct task_struct *p, int nice) #endif int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, - unsigned long arg4, unsigned long arg5, long *rc_p) + unsigned long arg4, unsigned long arg5) { - struct cred *cred = current_cred(); + struct cred *new; long error = 0; + new = prepare_creds(); + if (!new) + return -ENOMEM; + switch (option) { case PR_CAPBSET_READ: + error = -EINVAL; if (!cap_valid(arg2)) - error = -EINVAL; - else - error = !!cap_raised(cred->cap_bset, arg2); - break; + goto error; + error = !!cap_raised(new->cap_bset, arg2); + goto no_change; + #ifdef CONFIG_SECURITY_FILE_CAPABILITIES case PR_CAPBSET_DROP: - error = cap_prctl_drop(arg2); - break; + error = cap_prctl_drop(new, arg2); + if (error < 0) + goto error; + goto changed; /* * The next four prctl's remain to assist with transitioning a @@ -692,12 +676,12 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, * capability-based-privilege environment. */ case PR_SET_SECUREBITS: - if ((((cred->securebits & SECURE_ALL_LOCKS) >> 1) - & (cred->securebits ^ arg2)) /*[1]*/ - || ((cred->securebits & SECURE_ALL_LOCKS - & ~arg2)) /*[2]*/ - || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ - || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0)) { /*[4]*/ + error = -EPERM; + if ((((new->securebits & SECURE_ALL_LOCKS) >> 1) + & (new->securebits ^ arg2)) /*[1]*/ + || ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ + || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ + || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0) /*[4]*/ /* * [1] no changing of bits that are locked * [2] no unlocking of locks @@ -705,50 +689,51 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, * [4] doing anything requires privilege (go read about * the "sendmail capabilities bug") */ - error = -EPERM; /* cannot change a locked bit */ - } else { - cred->securebits = arg2; - } - break; + ) + /* cannot change a locked bit */ + goto error; + new->securebits = arg2; + goto changed; + case PR_GET_SECUREBITS: - error = cred->securebits; - break; + error = new->securebits; + goto no_change; #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ case PR_GET_KEEPCAPS: if (issecure(SECURE_KEEP_CAPS)) error = 1; - break; + goto no_change; + case PR_SET_KEEPCAPS: + error = -EINVAL; if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ - error = -EINVAL; - else if (issecure(SECURE_KEEP_CAPS_LOCKED)) - error = -EPERM; - else if (arg2) - cred->securebits |= issecure_mask(SECURE_KEEP_CAPS); + goto error; + error = -EPERM; + if (issecure(SECURE_KEEP_CAPS_LOCKED)) + goto error; + if (arg2) + new->securebits |= issecure_mask(SECURE_KEEP_CAPS); else - cred->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); - break; + new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); + goto changed; default: /* No functionality available - continue with default */ - return 0; + error = -ENOSYS; + goto error; } /* Functionality provided */ - *rc_p = error; - return 1; -} - -void cap_task_reparent_to_init (struct task_struct *p) -{ - struct cred *cred = p->cred; - - cap_set_init_eff(cred->cap_effective); - cap_clear(cred->cap_inheritable); - cap_set_full(cred->cap_permitted); - p->cred->securebits = SECUREBITS_DEFAULT; +changed: + return commit_creds(new); + +no_change: + error = 0; +error: + abort_creds(new); + return error; } int cap_syslog (int type) diff --git a/security/keys/internal.h b/security/keys/internal.h index d1586c629788..81932abefe7b 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -12,6 +12,7 @@ #ifndef _INTERNAL_H #define _INTERNAL_H +#include #include static inline __attribute__((format(printf, 1, 2))) @@ -25,7 +26,7 @@ void no_printk(const char *fmt, ...) #define kleave(FMT, ...) \ printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) #define kdebug(FMT, ...) \ - printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__) + printk(KERN_DEBUG " "FMT"\n", ##__VA_ARGS__) #else #define kenter(FMT, ...) \ no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) @@ -97,7 +98,7 @@ extern struct key *keyring_search_instkey(struct key *keyring, typedef int (*key_match_func_t)(const struct key *, const void *); extern key_ref_t keyring_search_aux(key_ref_t keyring_ref, - struct task_struct *tsk, + const struct cred *cred, struct key_type *type, const void *description, key_match_func_t match); @@ -105,13 +106,13 @@ extern key_ref_t keyring_search_aux(key_ref_t keyring_ref, extern key_ref_t search_process_keyrings(struct key_type *type, const void *description, key_match_func_t match, - struct task_struct *tsk); + const struct cred *cred); extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check); extern int install_user_keyrings(void); -extern int install_thread_keyring(void); -extern int install_process_keyring(void); +extern int install_thread_keyring_to_cred(struct cred *); +extern int install_process_keyring_to_cred(struct cred *); extern struct key *request_key_and_link(struct key_type *type, const char *description, @@ -130,12 +131,12 @@ extern long join_session_keyring(const char *name); * check to see whether permission is granted to use a key in the desired way */ extern int key_task_permission(const key_ref_t key_ref, - struct task_struct *context, + const struct cred *cred, key_perm_t perm); static inline int key_permission(const key_ref_t key_ref, key_perm_t perm) { - return key_task_permission(key_ref, current, perm); + return key_task_permission(key_ref, current_cred(), perm); } /* required permissions */ @@ -153,7 +154,7 @@ static inline int key_permission(const key_ref_t key_ref, key_perm_t perm) struct request_key_auth { struct key *target_key; struct key *dest_keyring; - struct task_struct *context; + const struct cred *cred; void *callout_info; size_t callout_len; pid_t pid; diff --git a/security/keys/key.c b/security/keys/key.c index a6ca39ed3b0e..f76c8a546fd3 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -218,7 +218,7 @@ serial_exists: * instantiate the key or discard it before returning */ struct key *key_alloc(struct key_type *type, const char *desc, - uid_t uid, gid_t gid, struct task_struct *ctx, + uid_t uid, gid_t gid, const struct cred *cred, key_perm_t perm, unsigned long flags) { struct key_user *user = NULL; @@ -294,7 +294,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, #endif /* let the security module know about the key */ - ret = security_key_alloc(key, ctx, flags); + ret = security_key_alloc(key, cred, flags); if (ret < 0) goto security_error; @@ -391,7 +391,7 @@ static int __key_instantiate_and_link(struct key *key, const void *data, size_t datalen, struct key *keyring, - struct key *instkey) + struct key *authkey) { int ret, awaken; @@ -421,8 +421,8 @@ static int __key_instantiate_and_link(struct key *key, ret = __key_link(keyring, key); /* disable the authorisation key */ - if (instkey) - key_revoke(instkey); + if (authkey) + key_revoke(authkey); } } @@ -444,14 +444,14 @@ int key_instantiate_and_link(struct key *key, const void *data, size_t datalen, struct key *keyring, - struct key *instkey) + struct key *authkey) { int ret; if (keyring) down_write(&keyring->sem); - ret = __key_instantiate_and_link(key, data, datalen, keyring, instkey); + ret = __key_instantiate_and_link(key, data, datalen, keyring, authkey); if (keyring) up_write(&keyring->sem); @@ -469,7 +469,7 @@ EXPORT_SYMBOL(key_instantiate_and_link); int key_negate_and_link(struct key *key, unsigned timeout, struct key *keyring, - struct key *instkey) + struct key *authkey) { struct timespec now; int ret, awaken; @@ -504,8 +504,8 @@ int key_negate_and_link(struct key *key, ret = __key_link(keyring, key); /* disable the authorisation key */ - if (instkey) - key_revoke(instkey); + if (authkey) + key_revoke(authkey); } mutex_unlock(&key_construction_mutex); @@ -743,6 +743,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, key_perm_t perm, unsigned long flags) { + const struct cred *cred = current_cred(); struct key_type *ktype; struct key *keyring, *key = NULL; key_ref_t key_ref; @@ -802,8 +803,8 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, } /* allocate a new key */ - key = key_alloc(ktype, description, current_fsuid(), current_fsgid(), - current, perm, flags); + key = key_alloc(ktype, description, cred->fsuid, cred->fsgid, cred, + perm, flags); if (IS_ERR(key)) { key_ref = ERR_CAST(key); goto error_3; diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 8833b447adef..7c72baa02f2e 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -866,6 +866,23 @@ static long get_instantiation_keyring(key_serial_t ringid, return -ENOKEY; } +/* + * change the request_key authorisation key on the current process + */ +static int keyctl_change_reqkey_auth(struct key *key) +{ + struct cred *new; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + key_put(new->request_key_auth); + new->request_key_auth = key_get(key); + + return commit_creds(new); +} + /*****************************************************************************/ /* * instantiate the key with the specified payload, and, if one is given, link @@ -876,12 +893,15 @@ long keyctl_instantiate_key(key_serial_t id, size_t plen, key_serial_t ringid) { + const struct cred *cred = current_cred(); struct request_key_auth *rka; struct key *instkey, *dest_keyring; void *payload; long ret; bool vm = false; + kenter("%d,,%zu,%d", id, plen, ringid); + ret = -EINVAL; if (plen > 1024 * 1024 - 1) goto error; @@ -889,7 +909,7 @@ long keyctl_instantiate_key(key_serial_t id, /* the appropriate instantiation authorisation key must have been * assumed before calling this */ ret = -EPERM; - instkey = current->cred->request_key_auth; + instkey = cred->request_key_auth; if (!instkey) goto error; @@ -931,10 +951,8 @@ long keyctl_instantiate_key(key_serial_t id, /* discard the assumed authority if it's just been disabled by * instantiation of the key */ - if (ret == 0) { - key_put(current->cred->request_key_auth); - current->cred->request_key_auth = NULL; - } + if (ret == 0) + keyctl_change_reqkey_auth(NULL); error2: if (!vm) @@ -953,14 +971,17 @@ error: */ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) { + const struct cred *cred = current_cred(); struct request_key_auth *rka; struct key *instkey, *dest_keyring; long ret; + kenter("%d,%u,%d", id, timeout, ringid); + /* the appropriate instantiation authorisation key must have been * assumed before calling this */ ret = -EPERM; - instkey = current->cred->request_key_auth; + instkey = cred->request_key_auth; if (!instkey) goto error; @@ -982,10 +1003,8 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) /* discard the assumed authority if it's just been disabled by * instantiation of the key */ - if (ret == 0) { - key_put(current->cred->request_key_auth); - current->cred->request_key_auth = NULL; - } + if (ret == 0) + keyctl_change_reqkey_auth(NULL); error: return ret; @@ -999,36 +1018,56 @@ error: */ long keyctl_set_reqkey_keyring(int reqkey_defl) { - struct cred *cred = current->cred; - int ret; + struct cred *new; + int ret, old_setting; + + old_setting = current_cred_xxx(jit_keyring); + + if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE) + return old_setting; + + new = prepare_creds(); + if (!new) + return -ENOMEM; switch (reqkey_defl) { case KEY_REQKEY_DEFL_THREAD_KEYRING: - ret = install_thread_keyring(); + ret = install_thread_keyring_to_cred(new); if (ret < 0) - return ret; + goto error; goto set; case KEY_REQKEY_DEFL_PROCESS_KEYRING: - ret = install_process_keyring(); - if (ret < 0) - return ret; + ret = install_process_keyring_to_cred(new); + if (ret < 0) { + if (ret != -EEXIST) + goto error; + ret = 0; + } + goto set; case KEY_REQKEY_DEFL_DEFAULT: case KEY_REQKEY_DEFL_SESSION_KEYRING: case KEY_REQKEY_DEFL_USER_KEYRING: case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: - set: - cred->jit_keyring = reqkey_defl; + case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: + goto set; case KEY_REQKEY_DEFL_NO_CHANGE: - return cred->jit_keyring; - case KEY_REQKEY_DEFL_GROUP_KEYRING: default: - return -EINVAL; + ret = -EINVAL; + goto error; } +set: + new->jit_keyring = reqkey_defl; + commit_creds(new); + return old_setting; +error: + abort_creds(new); + return -EINVAL; + } /* end keyctl_set_reqkey_keyring() */ /*****************************************************************************/ @@ -1087,9 +1126,7 @@ long keyctl_assume_authority(key_serial_t id) /* we divest ourselves of authority if given an ID of 0 */ if (id == 0) { - key_put(current->cred->request_key_auth); - current->cred->request_key_auth = NULL; - ret = 0; + ret = keyctl_change_reqkey_auth(NULL); goto error; } @@ -1104,10 +1141,12 @@ long keyctl_assume_authority(key_serial_t id) goto error; } - key_put(current->cred->request_key_auth); - current->cred->request_key_auth = authkey; - ret = authkey->serial; + ret = keyctl_change_reqkey_auth(authkey); + if (ret < 0) + goto error; + key_put(authkey); + ret = authkey->serial; error: return ret; diff --git a/security/keys/keyring.c b/security/keys/keyring.c index fdf75f901991..ed851574d073 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -245,14 +245,14 @@ static long keyring_read(const struct key *keyring, * allocate a keyring and link into the destination keyring */ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, - struct task_struct *ctx, unsigned long flags, + const struct cred *cred, unsigned long flags, struct key *dest) { struct key *keyring; int ret; keyring = key_alloc(&key_type_keyring, description, - uid, gid, ctx, + uid, gid, cred, (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, flags); @@ -281,7 +281,7 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, * - we propagate the possession attribute from the keyring ref to the key ref */ key_ref_t keyring_search_aux(key_ref_t keyring_ref, - struct task_struct *context, + const struct cred *cred, struct key_type *type, const void *description, key_match_func_t match) @@ -304,7 +304,7 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref, key_check(keyring); /* top keyring must have search permission to begin the search */ - err = key_task_permission(keyring_ref, context, KEY_SEARCH); + err = key_task_permission(keyring_ref, cred, KEY_SEARCH); if (err < 0) { key_ref = ERR_PTR(err); goto error; @@ -377,7 +377,7 @@ descend: /* key must have search permissions */ if (key_task_permission(make_key_ref(key, possessed), - context, KEY_SEARCH) < 0) + cred, KEY_SEARCH) < 0) continue; /* we set a different error code if we pass a negative key */ @@ -404,7 +404,7 @@ ascend: continue; if (key_task_permission(make_key_ref(key, possessed), - context, KEY_SEARCH) < 0) + cred, KEY_SEARCH) < 0) continue; /* stack the current position */ @@ -459,7 +459,7 @@ key_ref_t keyring_search(key_ref_t keyring, if (!type->match) return ERR_PTR(-ENOKEY); - return keyring_search_aux(keyring, current, + return keyring_search_aux(keyring, current->cred, type, description, type->match); } /* end keyring_search() */ diff --git a/security/keys/permission.c b/security/keys/permission.c index 13c36164f284..5d9fc7b93f2e 100644 --- a/security/keys/permission.c +++ b/security/keys/permission.c @@ -14,24 +14,27 @@ #include "internal.h" /*****************************************************************************/ -/* - * check to see whether permission is granted to use a key in the desired way, - * but permit the security modules to override +/** + * key_task_permission - Check a key can be used + * @key_ref: The key to check + * @cred: The credentials to use + * @perm: The permissions to check for + * + * Check to see whether permission is granted to use a key in the desired way, + * but permit the security modules to override. + * + * The caller must hold either a ref on cred or must hold the RCU readlock or a + * spinlock. */ -int key_task_permission(const key_ref_t key_ref, - struct task_struct *context, +int key_task_permission(const key_ref_t key_ref, const struct cred *cred, key_perm_t perm) { - const struct cred *cred; struct key *key; key_perm_t kperm; int ret; key = key_ref_to_ptr(key_ref); - rcu_read_lock(); - cred = __task_cred(context); - /* use the second 8-bits of permissions for keys the caller owns */ if (key->uid == cred->fsuid) { kperm = key->perm >> 16; @@ -57,7 +60,6 @@ int key_task_permission(const key_ref_t key_ref, kperm = key->perm; use_these_perms: - rcu_read_lock(); /* use the top 8-bits of permissions for keys the caller possesses * - possessor permissions are additive with other permissions @@ -71,7 +73,7 @@ use_these_perms: return -EACCES; /* let LSM be the final arbiter */ - return security_key_permission(key_ref, context, perm); + return security_key_permission(key_ref, cred, perm); } /* end key_task_permission() */ diff --git a/security/keys/proc.c b/security/keys/proc.c index f619170da760..7f508def50e3 100644 --- a/security/keys/proc.c +++ b/security/keys/proc.c @@ -136,8 +136,12 @@ static int proc_keys_show(struct seq_file *m, void *v) int rc; /* check whether the current task is allowed to view the key (assuming - * non-possession) */ - rc = key_task_permission(make_key_ref(key, 0), current, KEY_VIEW); + * non-possession) + * - the caller holds a spinlock, and thus the RCU read lock, making our + * access to __current_cred() safe + */ + rc = key_task_permission(make_key_ref(key, 0), current_cred(), + KEY_VIEW); if (rc < 0) return 0; diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 70ee93406f30..df329f684a65 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -42,11 +42,15 @@ struct key_user root_key_user = { */ int install_user_keyrings(void) { - struct user_struct *user = current->cred->user; + struct user_struct *user; + const struct cred *cred; struct key *uid_keyring, *session_keyring; char buf[20]; int ret; + cred = current_cred(); + user = cred->user; + kenter("%p{%u}", user, user->uid); if (user->uid_keyring) { @@ -67,7 +71,7 @@ int install_user_keyrings(void) uid_keyring = find_keyring_by_name(buf, true); if (IS_ERR(uid_keyring)) { uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, - current, KEY_ALLOC_IN_QUOTA, + cred, KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(uid_keyring)) { ret = PTR_ERR(uid_keyring); @@ -83,8 +87,7 @@ int install_user_keyrings(void) if (IS_ERR(session_keyring)) { session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, - current, KEY_ALLOC_IN_QUOTA, - NULL); + cred, KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(session_keyring)) { ret = PTR_ERR(session_keyring); goto error_release; @@ -116,142 +119,128 @@ error: return ret; } -/*****************************************************************************/ /* - * deal with the UID changing + * install a fresh thread keyring directly to new credentials */ -void switch_uid_keyring(struct user_struct *new_user) +int install_thread_keyring_to_cred(struct cred *new) { -#if 0 /* do nothing for now */ - struct key *old; - - /* switch to the new user's session keyring if we were running under - * root's default session keyring */ - if (new_user->uid != 0 && - current->session_keyring == &root_session_keyring - ) { - atomic_inc(&new_user->session_keyring->usage); - - task_lock(current); - old = current->session_keyring; - current->session_keyring = new_user->session_keyring; - task_unlock(current); + struct key *keyring; - key_put(old); - } -#endif + keyring = keyring_alloc("_tid", new->uid, new->gid, new, + KEY_ALLOC_QUOTA_OVERRUN, NULL); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); -} /* end switch_uid_keyring() */ + new->thread_keyring = keyring; + return 0; +} -/*****************************************************************************/ /* * install a fresh thread keyring, discarding the old one */ -int install_thread_keyring(void) +static int install_thread_keyring(void) { - struct task_struct *tsk = current; - struct key *keyring, *old; - char buf[20]; + struct cred *new; int ret; - sprintf(buf, "_tid.%u", tsk->pid); + new = prepare_creds(); + if (!new) + return -ENOMEM; - keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk, - KEY_ALLOC_QUOTA_OVERRUN, NULL); - if (IS_ERR(keyring)) { - ret = PTR_ERR(keyring); - goto error; + BUG_ON(new->thread_keyring); + + ret = install_thread_keyring_to_cred(new); + if (ret < 0) { + abort_creds(new); + return ret; } - task_lock(tsk); - old = tsk->cred->thread_keyring; - tsk->cred->thread_keyring = keyring; - task_unlock(tsk); + return commit_creds(new); +} - ret = 0; +/* + * install a process keyring directly to a credentials struct + * - returns -EEXIST if there was already a process keyring, 0 if one installed, + * and other -ve on any other error + */ +int install_process_keyring_to_cred(struct cred *new) +{ + struct key *keyring; + int ret; - key_put(old); -error: + if (new->tgcred->process_keyring) + return -EEXIST; + + keyring = keyring_alloc("_pid", new->uid, new->gid, + new, KEY_ALLOC_QUOTA_OVERRUN, NULL); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); + + spin_lock_irq(&new->tgcred->lock); + if (!new->tgcred->process_keyring) { + new->tgcred->process_keyring = keyring; + keyring = NULL; + ret = 0; + } else { + ret = -EEXIST; + } + spin_unlock_irq(&new->tgcred->lock); + key_put(keyring); return ret; +} -} /* end install_thread_keyring() */ - -/*****************************************************************************/ /* * make sure a process keyring is installed + * - we */ -int install_process_keyring(void) +static int install_process_keyring(void) { - struct task_struct *tsk = current; - struct key *keyring; - char buf[20]; + struct cred *new; int ret; - might_sleep(); - - if (!tsk->cred->tgcred->process_keyring) { - sprintf(buf, "_pid.%u", tsk->tgid); - - keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk, - KEY_ALLOC_QUOTA_OVERRUN, NULL); - if (IS_ERR(keyring)) { - ret = PTR_ERR(keyring); - goto error; - } - - /* attach keyring */ - spin_lock_irq(&tsk->cred->tgcred->lock); - if (!tsk->cred->tgcred->process_keyring) { - tsk->cred->tgcred->process_keyring = keyring; - keyring = NULL; - } - spin_unlock_irq(&tsk->cred->tgcred->lock); + new = prepare_creds(); + if (!new) + return -ENOMEM; - key_put(keyring); + ret = install_process_keyring_to_cred(new); + if (ret < 0) { + abort_creds(new); + return ret != -EEXIST ?: 0; } - ret = 0; -error: - return ret; - -} /* end install_process_keyring() */ + return commit_creds(new); +} -/*****************************************************************************/ /* - * install a session keyring, discarding the old one - * - if a keyring is not supplied, an empty one is invented + * install a session keyring directly to a credentials struct */ -static int install_session_keyring(struct key *keyring) +static int install_session_keyring_to_cred(struct cred *cred, + struct key *keyring) { - struct task_struct *tsk = current; unsigned long flags; struct key *old; - char buf[20]; might_sleep(); /* create an empty session keyring */ if (!keyring) { - sprintf(buf, "_ses.%u", tsk->tgid); - flags = KEY_ALLOC_QUOTA_OVERRUN; - if (tsk->cred->tgcred->session_keyring) + if (cred->tgcred->session_keyring) flags = KEY_ALLOC_IN_QUOTA; - keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, - tsk, flags, NULL); + keyring = keyring_alloc("_ses", cred->uid, cred->gid, + cred, flags, NULL); if (IS_ERR(keyring)) return PTR_ERR(keyring); - } - else { + } else { atomic_inc(&keyring->usage); } /* install the keyring */ - spin_lock_irq(&tsk->cred->tgcred->lock); - old = tsk->cred->tgcred->session_keyring; - rcu_assign_pointer(tsk->cred->tgcred->session_keyring, keyring); - spin_unlock_irq(&tsk->cred->tgcred->lock); + spin_lock_irq(&cred->tgcred->lock); + old = cred->tgcred->session_keyring; + rcu_assign_pointer(cred->tgcred->session_keyring, keyring); + spin_unlock_irq(&cred->tgcred->lock); /* we're using RCU on the pointer, but there's no point synchronising * on it if it didn't previously point to anything */ @@ -261,38 +250,29 @@ static int install_session_keyring(struct key *keyring) } return 0; +} -} /* end install_session_keyring() */ - -/*****************************************************************************/ /* - * copy the keys for fork + * install a session keyring, discarding the old one + * - if a keyring is not supplied, an empty one is invented */ -int copy_keys(unsigned long clone_flags, struct task_struct *tsk) +static int install_session_keyring(struct key *keyring) { - key_check(tsk->cred->thread_keyring); - key_check(tsk->cred->request_key_auth); - - /* no thread keyring yet */ - tsk->cred->thread_keyring = NULL; - - /* copy the request_key() authorisation for this thread */ - key_get(tsk->cred->request_key_auth); - - return 0; + struct cred *new; + int ret; -} /* end copy_keys() */ + new = prepare_creds(); + if (!new) + return -ENOMEM; -/*****************************************************************************/ -/* - * dispose of per-thread keys upon thread exit - */ -void exit_keys(struct task_struct *tsk) -{ - key_put(tsk->cred->thread_keyring); - key_put(tsk->cred->request_key_auth); + ret = install_session_keyring_to_cred(new, NULL); + if (ret < 0) { + abort_creds(new); + return ret; + } -} /* end exit_keys() */ + return commit_creds(new); +} /*****************************************************************************/ /* @@ -300,38 +280,41 @@ void exit_keys(struct task_struct *tsk) */ int exec_keys(struct task_struct *tsk) { - struct key *old; + struct thread_group_cred *tgcred = NULL; + struct cred *new; - /* newly exec'd tasks don't get a thread keyring */ - task_lock(tsk); - old = tsk->cred->thread_keyring; - tsk->cred->thread_keyring = NULL; - task_unlock(tsk); +#ifdef CONFIG_KEYS + tgcred = kmalloc(sizeof(*tgcred), GFP_KERNEL); + if (!tgcred) + return -ENOMEM; +#endif - key_put(old); + new = prepare_creds(); + if (new < 0) + return -ENOMEM; - /* discard the process keyring from a newly exec'd task */ - spin_lock_irq(&tsk->cred->tgcred->lock); - old = tsk->cred->tgcred->process_keyring; - tsk->cred->tgcred->process_keyring = NULL; - spin_unlock_irq(&tsk->cred->tgcred->lock); + /* newly exec'd tasks don't get a thread keyring */ + key_put(new->thread_keyring); + new->thread_keyring = NULL; - key_put(old); + /* create a new per-thread-group creds for all this set of threads to + * share */ + memcpy(tgcred, new->tgcred, sizeof(struct thread_group_cred)); - return 0; + atomic_set(&tgcred->usage, 1); + spin_lock_init(&tgcred->lock); -} /* end exec_keys() */ + /* inherit the session keyring; new process keyring */ + key_get(tgcred->session_keyring); + tgcred->process_keyring = NULL; -/*****************************************************************************/ -/* - * deal with SUID programs - * - we might want to make this invent a new session keyring - */ -int suid_keys(struct task_struct *tsk) -{ + release_tgcred(new); + new->tgcred = tgcred; + + commit_creds(new); return 0; -} /* end suid_keys() */ +} /* end exec_keys() */ /*****************************************************************************/ /* @@ -376,16 +359,13 @@ void key_fsgid_changed(struct task_struct *tsk) key_ref_t search_process_keyrings(struct key_type *type, const void *description, key_match_func_t match, - struct task_struct *context) + const struct cred *cred) { struct request_key_auth *rka; - struct cred *cred; key_ref_t key_ref, ret, err; might_sleep(); - cred = get_task_cred(context); - /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were * searchable, but we failed to find a key or we found a negative key; * otherwise we want to return a sample error (probably -EACCES) if @@ -401,7 +381,7 @@ key_ref_t search_process_keyrings(struct key_type *type, if (cred->thread_keyring) { key_ref = keyring_search_aux( make_key_ref(cred->thread_keyring, 1), - context, type, description, match); + cred, type, description, match); if (!IS_ERR(key_ref)) goto found; @@ -422,7 +402,7 @@ key_ref_t search_process_keyrings(struct key_type *type, if (cred->tgcred->process_keyring) { key_ref = keyring_search_aux( make_key_ref(cred->tgcred->process_keyring, 1), - context, type, description, match); + cred, type, description, match); if (!IS_ERR(key_ref)) goto found; @@ -446,7 +426,7 @@ key_ref_t search_process_keyrings(struct key_type *type, make_key_ref(rcu_dereference( cred->tgcred->session_keyring), 1), - context, type, description, match); + cred, type, description, match); rcu_read_unlock(); if (!IS_ERR(key_ref)) @@ -468,7 +448,7 @@ key_ref_t search_process_keyrings(struct key_type *type, else if (cred->user->session_keyring) { key_ref = keyring_search_aux( make_key_ref(cred->user->session_keyring, 1), - context, type, description, match); + cred, type, description, match); if (!IS_ERR(key_ref)) goto found; @@ -490,7 +470,7 @@ key_ref_t search_process_keyrings(struct key_type *type, * - we don't permit access to request_key auth keys via this method */ if (cred->request_key_auth && - context == current && + cred == current_cred() && type != &key_type_request_key_auth ) { /* defend against the auth key being revoked */ @@ -500,7 +480,7 @@ key_ref_t search_process_keyrings(struct key_type *type, rka = cred->request_key_auth->payload.data; key_ref = search_process_keyrings(type, description, - match, rka->context); + match, rka->cred); up_read(&cred->request_key_auth->sem); @@ -527,7 +507,6 @@ key_ref_t search_process_keyrings(struct key_type *type, key_ref = ret ? ret : err; found: - put_cred(cred); return key_ref; } /* end search_process_keyrings() */ @@ -552,8 +531,7 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial, key_perm_t perm) { struct request_key_auth *rka; - struct task_struct *t = current; - struct cred *cred; + const struct cred *cred; struct key *key; key_ref_t key_ref, skey_ref; int ret; @@ -608,6 +586,7 @@ try_again: goto error; ret = install_session_keyring( cred->user->session_keyring); + if (ret < 0) goto error; goto reget_creds; @@ -693,7 +672,7 @@ try_again: /* check to see if we possess the key */ skey_ref = search_process_keyrings(key->type, key, lookup_user_key_possessed, - current); + cred); if (!IS_ERR(skey_ref)) { key_put(key); @@ -725,7 +704,7 @@ try_again: goto invalid_key; /* check the permissions */ - ret = key_task_permission(key_ref, t, perm); + ret = key_task_permission(key_ref, cred, perm); if (ret < 0) goto invalid_key; @@ -755,21 +734,33 @@ reget_creds: */ long join_session_keyring(const char *name) { - struct task_struct *tsk = current; - struct cred *cred = current->cred; + const struct cred *old; + struct cred *new; struct key *keyring; - long ret; + long ret, serial; + + /* only permit this if there's a single thread in the thread group - + * this avoids us having to adjust the creds on all threads and risking + * ENOMEM */ + if (!is_single_threaded(current)) + return -EMLINK; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + old = current_cred(); /* if no name is provided, install an anonymous keyring */ if (!name) { - ret = install_session_keyring(NULL); + ret = install_session_keyring_to_cred(new, NULL); if (ret < 0) goto error; - rcu_read_lock(); - ret = rcu_dereference(cred->tgcred->session_keyring)->serial; - rcu_read_unlock(); - goto error; + serial = new->tgcred->session_keyring->serial; + ret = commit_creds(new); + if (ret == 0) + ret = serial; + goto okay; } /* allow the user to join or create a named keyring */ @@ -779,29 +770,33 @@ long join_session_keyring(const char *name) keyring = find_keyring_by_name(name, false); if (PTR_ERR(keyring) == -ENOKEY) { /* not found - try and create a new one */ - keyring = keyring_alloc(name, cred->uid, cred->gid, tsk, + keyring = keyring_alloc(name, old->uid, old->gid, old, KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error2; } - } - else if (IS_ERR(keyring)) { + } else if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error2; } /* we've got a keyring - now to install it */ - ret = install_session_keyring(keyring); + ret = install_session_keyring_to_cred(new, keyring); if (ret < 0) goto error2; + commit_creds(new); + mutex_unlock(&key_session_mutex); + ret = keyring->serial; key_put(keyring); +okay: + return ret; error2: mutex_unlock(&key_session_mutex); error: + abort_creds(new); return ret; - -} /* end join_session_keyring() */ +} diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 3d12558362df..0e04f72ef2d4 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -83,8 +83,10 @@ static int call_sbin_request_key(struct key_construction *cons, /* allocate a new session keyring */ sprintf(desc, "_req.%u", key->serial); - keyring = keyring_alloc(desc, current_fsuid(), current_fsgid(), current, + cred = get_current_cred(); + keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred, KEY_ALLOC_QUOTA_OVERRUN, NULL); + put_cred(cred); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error_alloc; @@ -104,8 +106,7 @@ static int call_sbin_request_key(struct key_construction *cons, /* we specify the process's default keyrings */ sprintf(keyring_str[0], "%d", - cred->thread_keyring ? - cred->thread_keyring->serial : 0); + cred->thread_keyring ? cred->thread_keyring->serial : 0); prkey = 0; if (cred->tgcred->process_keyring) @@ -155,8 +156,8 @@ error_link: key_put(keyring); error_alloc: - kleave(" = %d", ret); complete_request_key(cons, ret); + kleave(" = %d", ret); return ret; } @@ -295,6 +296,7 @@ static int construct_alloc_key(struct key_type *type, struct key_user *user, struct key **_key) { + const struct cred *cred = current_cred(); struct key *key; key_ref_t key_ref; @@ -302,9 +304,8 @@ static int construct_alloc_key(struct key_type *type, mutex_lock(&user->cons_lock); - key = key_alloc(type, description, - current_fsuid(), current_fsgid(), current, KEY_POS_ALL, - flags); + key = key_alloc(type, description, cred->fsuid, cred->fsgid, cred, + KEY_POS_ALL, flags); if (IS_ERR(key)) goto alloc_failed; @@ -317,8 +318,7 @@ static int construct_alloc_key(struct key_type *type, * waited for locks */ mutex_lock(&key_construction_mutex); - key_ref = search_process_keyrings(type, description, type->match, - current); + key_ref = search_process_keyrings(type, description, type->match, cred); if (!IS_ERR(key_ref)) goto key_already_present; @@ -363,6 +363,8 @@ static struct key *construct_key_and_link(struct key_type *type, struct key *key; int ret; + kenter(""); + user = key_user_lookup(current_fsuid()); if (!user) return ERR_PTR(-ENOMEM); @@ -376,17 +378,21 @@ static struct key *construct_key_and_link(struct key_type *type, if (ret == 0) { ret = construct_key(key, callout_info, callout_len, aux, dest_keyring); - if (ret < 0) + if (ret < 0) { + kdebug("cons failed"); goto construction_failed; + } } key_put(dest_keyring); + kleave(" = key %d", key_serial(key)); return key; construction_failed: key_negate_and_link(key, key_negative_timeout, NULL, NULL); key_put(key); key_put(dest_keyring); + kleave(" = %d", ret); return ERR_PTR(ret); } @@ -405,6 +411,7 @@ struct key *request_key_and_link(struct key_type *type, struct key *dest_keyring, unsigned long flags) { + const struct cred *cred = current_cred(); struct key *key; key_ref_t key_ref; @@ -414,7 +421,7 @@ struct key *request_key_and_link(struct key_type *type, /* search all the process keyrings for a key */ key_ref = search_process_keyrings(type, description, type->match, - current); + cred); if (!IS_ERR(key_ref)) { key = key_ref_to_ptr(key_ref); diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c index 2125579d5d73..86747151ee5b 100644 --- a/security/keys/request_key_auth.c +++ b/security/keys/request_key_auth.c @@ -105,9 +105,9 @@ static void request_key_auth_revoke(struct key *key) kenter("{%d}", key->serial); - if (rka->context) { - put_task_struct(rka->context); - rka->context = NULL; + if (rka->cred) { + put_cred(rka->cred); + rka->cred = NULL; } } /* end request_key_auth_revoke() */ @@ -122,9 +122,9 @@ static void request_key_auth_destroy(struct key *key) kenter("{%d}", key->serial); - if (rka->context) { - put_task_struct(rka->context); - rka->context = NULL; + if (rka->cred) { + put_cred(rka->cred); + rka->cred = NULL; } key_put(rka->target_key); @@ -143,6 +143,7 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, size_t callout_len, struct key *dest_keyring) { struct request_key_auth *rka, *irka; + const struct cred *cred = current->cred; struct key *authkey = NULL; char desc[20]; int ret; @@ -164,28 +165,25 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, /* see if the calling process is already servicing the key request of * another process */ - if (current->cred->request_key_auth) { + if (cred->request_key_auth) { /* it is - use that instantiation context here too */ - down_read(¤t->cred->request_key_auth->sem); + down_read(&cred->request_key_auth->sem); /* if the auth key has been revoked, then the key we're * servicing is already instantiated */ - if (test_bit(KEY_FLAG_REVOKED, - ¤t->cred->request_key_auth->flags)) + if (test_bit(KEY_FLAG_REVOKED, &cred->request_key_auth->flags)) goto auth_key_revoked; - irka = current->cred->request_key_auth->payload.data; - rka->context = irka->context; + irka = cred->request_key_auth->payload.data; + rka->cred = get_cred(irka->cred); rka->pid = irka->pid; - get_task_struct(rka->context); - up_read(¤t->cred->request_key_auth->sem); + up_read(&cred->request_key_auth->sem); } else { /* it isn't - use this process as the context */ - rka->context = current; + rka->cred = get_cred(cred); rka->pid = current->pid; - get_task_struct(rka->context); } rka->target_key = key_get(target); @@ -197,7 +195,7 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, sprintf(desc, "%x", target->serial); authkey = key_alloc(&key_type_request_key_auth, desc, - current_fsuid(), current_fsgid(), current, + cred->fsuid, cred->fsgid, cred, KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH | KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA); if (IS_ERR(authkey)) { @@ -205,16 +203,16 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info, goto error_alloc; } - /* construct and attach to the keyring */ + /* construct the auth key */ ret = key_instantiate_and_link(authkey, rka, 0, NULL, NULL); if (ret < 0) goto error_inst; - kleave(" = {%d}", authkey->serial); + kleave(" = {%d,%d}", authkey->serial, atomic_read(&authkey->usage)); return authkey; auth_key_revoked: - up_read(¤t->cred->request_key_auth->sem); + up_read(&cred->request_key_auth->sem); kfree(rka->callout_info); kfree(rka); kleave("= -EKEYREVOKED"); @@ -257,6 +255,7 @@ static int key_get_instantiation_authkey_match(const struct key *key, */ struct key *key_get_instantiation_authkey(key_serial_t target_id) { + const struct cred *cred = current_cred(); struct key *authkey; key_ref_t authkey_ref; @@ -264,7 +263,7 @@ struct key *key_get_instantiation_authkey(key_serial_t target_id) &key_type_request_key_auth, (void *) (unsigned long) target_id, key_get_instantiation_authkey_match, - current); + cred); if (IS_ERR(authkey_ref)) { authkey = ERR_CAST(authkey_ref); diff --git a/security/security.c b/security/security.c index f40a0a04c3c2..a55d739c6864 100644 --- a/security/security.c +++ b/security/security.c @@ -145,18 +145,13 @@ int security_capget(struct task_struct *target, return security_ops->capget(target, effective, inheritable, permitted); } -int security_capset_check(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted) +int security_capset(struct cred *new, const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { - return security_ops->capset_check(effective, inheritable, permitted); -} - -void security_capset_set(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted) -{ - security_ops->capset_set(effective, inheritable, permitted); + return security_ops->capset(new, old, + effective, inheritable, permitted); } int security_capable(struct task_struct *tsk, int cap) @@ -228,9 +223,9 @@ void security_bprm_free(struct linux_binprm *bprm) security_ops->bprm_free_security(bprm); } -void security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) +int security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) { - security_ops->bprm_apply_creds(bprm, unsafe); + return security_ops->bprm_apply_creds(bprm, unsafe); } void security_bprm_post_apply_creds(struct linux_binprm *bprm) @@ -616,14 +611,19 @@ int security_task_create(unsigned long clone_flags) return security_ops->task_create(clone_flags); } -int security_cred_alloc(struct cred *cred) +void security_cred_free(struct cred *cred) { - return security_ops->cred_alloc_security(cred); + security_ops->cred_free(cred); } -void security_cred_free(struct cred *cred) +int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) { - security_ops->cred_free(cred); + return security_ops->cred_prepare(new, old, gfp); +} + +void security_commit_creds(struct cred *new, const struct cred *old) +{ + return security_ops->cred_commit(new, old); } int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) @@ -631,10 +631,10 @@ int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) return security_ops->task_setuid(id0, id1, id2, flags); } -int security_task_post_setuid(uid_t old_ruid, uid_t old_euid, - uid_t old_suid, int flags) +int security_task_fix_setuid(struct cred *new, const struct cred *old, + int flags) { - return security_ops->task_post_setuid(old_ruid, old_euid, old_suid, flags); + return security_ops->task_fix_setuid(new, old, flags); } int security_task_setgid(gid_t id0, gid_t id1, gid_t id2, int flags) @@ -716,14 +716,9 @@ int security_task_wait(struct task_struct *p) } int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, - unsigned long arg4, unsigned long arg5, long *rc_p) -{ - return security_ops->task_prctl(option, arg2, arg3, arg4, arg5, rc_p); -} - -void security_task_reparent_to_init(struct task_struct *p) + unsigned long arg4, unsigned long arg5) { - security_ops->task_reparent_to_init(p); + return security_ops->task_prctl(option, arg2, arg3, arg4, arg5); } void security_task_to_inode(struct task_struct *p, struct inode *inode) @@ -1123,9 +1118,10 @@ EXPORT_SYMBOL(security_skb_classify_flow); #ifdef CONFIG_KEYS -int security_key_alloc(struct key *key, struct task_struct *tsk, unsigned long flags) +int security_key_alloc(struct key *key, const struct cred *cred, + unsigned long flags) { - return security_ops->key_alloc(key, tsk, flags); + return security_ops->key_alloc(key, cred, flags); } void security_key_free(struct key *key) @@ -1134,9 +1130,9 @@ void security_key_free(struct key *key) } int security_key_permission(key_ref_t key_ref, - struct task_struct *context, key_perm_t perm) + const struct cred *cred, key_perm_t perm) { - return security_ops->key_permission(key_ref, context, perm); + return security_ops->key_permission(key_ref, cred, perm); } int security_key_getsecurity(struct key *key, char **_buffer) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index f20cbd681ba6..c71bba78872f 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -156,20 +156,20 @@ static int selinux_secmark_enabled(void) return (atomic_read(&selinux_secmark_refcount) > 0); } -/* Allocate and free functions for each kind of security blob. */ - -static int cred_alloc_security(struct cred *cred) +/* + * initialise the security for the init task + */ +static void cred_init_security(void) { + struct cred *cred = (struct cred *) current->cred; struct task_security_struct *tsec; tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); if (!tsec) - return -ENOMEM; + panic("SELinux: Failed to initialize initial task.\n"); - tsec->osid = tsec->sid = SECINITSID_UNLABELED; + tsec->osid = tsec->sid = SECINITSID_KERNEL; cred->security = tsec; - - return 0; } /* @@ -1378,6 +1378,19 @@ static inline u32 signal_to_av(int sig) return perm; } +/* + * Check permission between a pair of credentials + * fork check, ptrace check, etc. + */ +static int cred_has_perm(const struct cred *actor, + const struct cred *target, + u32 perms) +{ + u32 asid = cred_sid(actor), tsid = cred_sid(target); + + return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL); +} + /* * Check permission between a pair of tasks, e.g. signal checks, * fork check, ptrace check, etc. @@ -1820,24 +1833,19 @@ static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, return secondary_ops->capget(target, effective, inheritable, permitted); } -static int selinux_capset_check(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted) +static int selinux_capset(struct cred *new, const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) { int error; - error = secondary_ops->capset_check(effective, inheritable, permitted); + error = secondary_ops->capset(new, old, + effective, inheritable, permitted); if (error) return error; - return task_has_perm(current, current, PROCESS__SETCAP); -} - -static void selinux_capset_set(const kernel_cap_t *effective, - const kernel_cap_t *inheritable, - const kernel_cap_t *permitted) -{ - secondary_ops->capset_set(effective, inheritable, permitted); + return cred_has_perm(old, new, PROCESS__SETCAP); } static int selinux_capable(struct task_struct *tsk, int cap, int audit) @@ -2244,16 +2252,23 @@ static inline void flush_unauthorized_files(const struct cred *cred, spin_unlock(&files->file_lock); } -static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) +static int selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) { struct task_security_struct *tsec; struct bprm_security_struct *bsec; + struct cred *new; u32 sid; int rc; - secondary_ops->bprm_apply_creds(bprm, unsafe); + rc = secondary_ops->bprm_apply_creds(bprm, unsafe); + if (rc < 0) + return rc; - tsec = current_security(); + new = prepare_creds(); + if (!new) + return -ENOMEM; + + tsec = new->security; bsec = bprm->security; sid = bsec->sid; @@ -2268,7 +2283,7 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) PROCESS__SHARE, NULL); if (rc) { bsec->unsafe = 1; - return; + goto out; } } @@ -2292,12 +2307,16 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) PROCESS__PTRACE, NULL); if (rc) { bsec->unsafe = 1; - return; + goto out; } } } tsec->sid = sid; } + +out: + commit_creds(new); + return 0; } /* @@ -3021,6 +3040,7 @@ static int selinux_file_ioctl(struct file *file, unsigned int cmd, static int file_map_prot_check(struct file *file, unsigned long prot, int shared) { const struct cred *cred = current_cred(); + int rc = 0; #ifndef CONFIG_PPC32 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) { @@ -3029,9 +3049,9 @@ static int file_map_prot_check(struct file *file, unsigned long prot, int shared * private file mapping that will also be writable. * This has an additional check. */ - int rc = task_has_perm(current, current, PROCESS__EXECMEM); + rc = cred_has_perm(cred, cred, PROCESS__EXECMEM); if (rc) - return rc; + goto error; } #endif @@ -3048,7 +3068,9 @@ static int file_map_prot_check(struct file *file, unsigned long prot, int shared return file_has_perm(cred, file, av); } - return 0; + +error: + return rc; } static int selinux_file_mmap(struct file *file, unsigned long reqprot, @@ -3090,8 +3112,7 @@ static int selinux_file_mprotect(struct vm_area_struct *vma, rc = 0; if (vma->vm_start >= vma->vm_mm->start_brk && vma->vm_end <= vma->vm_mm->brk) { - rc = task_has_perm(current, current, - PROCESS__EXECHEAP); + rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP); } else if (!vma->vm_file && vma->vm_start <= vma->vm_mm->start_stack && vma->vm_end >= vma->vm_mm->start_stack) { @@ -3104,8 +3125,7 @@ static int selinux_file_mprotect(struct vm_area_struct *vma, * modified content. This typically should only * occur for text relocations. */ - rc = file_has_perm(cred, vma->vm_file, - FILE__EXECMOD); + rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); } if (rc) return rc; @@ -3211,6 +3231,7 @@ static int selinux_dentry_open(struct file *file, const struct cred *cred) struct file_security_struct *fsec; struct inode *inode; struct inode_security_struct *isec; + inode = file->f_path.dentry->d_inode; fsec = file->f_security; isec = inode->i_security; @@ -3247,38 +3268,41 @@ static int selinux_task_create(unsigned long clone_flags) return task_has_perm(current, current, PROCESS__FORK); } -static int selinux_cred_alloc_security(struct cred *cred) +/* + * detach and free the LSM part of a set of credentials + */ +static void selinux_cred_free(struct cred *cred) { - struct task_security_struct *tsec1, *tsec2; - int rc; - - tsec1 = current_security(); + struct task_security_struct *tsec = cred->security; + cred->security = NULL; + kfree(tsec); +} - rc = cred_alloc_security(cred); - if (rc) - return rc; - tsec2 = cred->security; +/* + * prepare a new set of credentials for modification + */ +static int selinux_cred_prepare(struct cred *new, const struct cred *old, + gfp_t gfp) +{ + const struct task_security_struct *old_tsec; + struct task_security_struct *tsec; - tsec2->osid = tsec1->osid; - tsec2->sid = tsec1->sid; + old_tsec = old->security; - /* Retain the exec, fs, key, and sock SIDs across fork */ - tsec2->exec_sid = tsec1->exec_sid; - tsec2->create_sid = tsec1->create_sid; - tsec2->keycreate_sid = tsec1->keycreate_sid; - tsec2->sockcreate_sid = tsec1->sockcreate_sid; + tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp); + if (!tsec) + return -ENOMEM; + new->security = tsec; return 0; } /* - * detach and free the LSM part of a set of credentials + * commit new credentials */ -static void selinux_cred_free(struct cred *cred) +static void selinux_cred_commit(struct cred *new, const struct cred *old) { - struct task_security_struct *tsec = cred->security; - cred->security = NULL; - kfree(tsec); + secondary_ops->cred_commit(new, old); } static int selinux_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) @@ -3292,9 +3316,10 @@ static int selinux_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) return 0; } -static int selinux_task_post_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) +static int selinux_task_fix_setuid(struct cred *new, const struct cred *old, + int flags) { - return secondary_ops->task_post_setuid(id0, id1, id2, flags); + return secondary_ops->task_fix_setuid(new, old, flags); } static int selinux_task_setgid(gid_t id0, gid_t id1, gid_t id2, int flags) @@ -3368,7 +3393,7 @@ static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim /* Control the ability to change the hard limit (whether lowering or raising it), so that the hard limit can later be used as a safe reset point for the soft limit - upon context transitions. See selinux_bprm_apply_creds. */ + upon context transitions. See selinux_bprm_committing_creds. */ if (old_rlim->rlim_max != new_rlim->rlim_max) return task_has_perm(current, current, PROCESS__SETRLIMIT); @@ -3422,13 +3447,12 @@ static int selinux_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, - unsigned long arg5, - long *rc_p) + unsigned long arg5) { /* The current prctl operations do not appear to require any SELinux controls since they merely observe or modify the state of the current process. */ - return secondary_ops->task_prctl(option, arg2, arg3, arg4, arg5, rc_p); + return secondary_ops->task_prctl(option, arg2, arg3, arg4, arg5); } static int selinux_task_wait(struct task_struct *p) @@ -3436,18 +3460,6 @@ static int selinux_task_wait(struct task_struct *p) return task_has_perm(p, current, PROCESS__SIGCHLD); } -static void selinux_task_reparent_to_init(struct task_struct *p) -{ - struct task_security_struct *tsec; - - secondary_ops->task_reparent_to_init(p); - - tsec = p->cred->security; - tsec->osid = tsec->sid; - tsec->sid = SECINITSID_KERNEL; - return; -} - static void selinux_task_to_inode(struct task_struct *p, struct inode *inode) { @@ -5325,7 +5337,8 @@ static int selinux_setprocattr(struct task_struct *p, { struct task_security_struct *tsec; struct task_struct *tracer; - u32 sid = 0; + struct cred *new; + u32 sid = 0, ptsid; int error; char *str = value; @@ -5372,86 +5385,75 @@ static int selinux_setprocattr(struct task_struct *p, return error; } + new = prepare_creds(); + if (!new) + return -ENOMEM; + /* Permission checking based on the specified context is performed during the actual operation (execve, open/mkdir/...), when we know the full context of the - operation. See selinux_bprm_set_security for the execve + operation. See selinux_bprm_set_creds for the execve checks and may_create for the file creation checks. The operation will then fail if the context is not permitted. */ - tsec = p->cred->security; - if (!strcmp(name, "exec")) + tsec = new->security; + if (!strcmp(name, "exec")) { tsec->exec_sid = sid; - else if (!strcmp(name, "fscreate")) + } else if (!strcmp(name, "fscreate")) { tsec->create_sid = sid; - else if (!strcmp(name, "keycreate")) { + } else if (!strcmp(name, "keycreate")) { error = may_create_key(sid, p); if (error) - return error; + goto abort_change; tsec->keycreate_sid = sid; - } else if (!strcmp(name, "sockcreate")) + } else if (!strcmp(name, "sockcreate")) { tsec->sockcreate_sid = sid; - else if (!strcmp(name, "current")) { - struct av_decision avd; - + } else if (!strcmp(name, "current")) { + error = -EINVAL; if (sid == 0) - return -EINVAL; - /* - * SELinux allows to change context in the following case only. - * - Single threaded processes. - * - Multi threaded processes intend to change its context into - * more restricted domain (defined by TYPEBOUNDS statement). - */ - if (atomic_read(&p->mm->mm_users) != 1) { - struct task_struct *g, *t; - struct mm_struct *mm = p->mm; - read_lock(&tasklist_lock); - do_each_thread(g, t) { - if (t->mm == mm && t != p) { - read_unlock(&tasklist_lock); - error = security_bounded_transition(tsec->sid, sid); - if (!error) - goto boundary_ok; - - return error; - } - } while_each_thread(g, t); - read_unlock(&tasklist_lock); + goto abort_change; + + /* Only allow single threaded processes to change context */ + error = -EPERM; + if (!is_single_threaded(p)) { + error = security_bounded_transition(tsec->sid, sid); + if (error) + goto abort_change; } -boundary_ok: /* Check permissions for the transition. */ error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS, PROCESS__DYNTRANSITION, NULL); if (error) - return error; + goto abort_change; /* Check for ptracing, and update the task SID if ok. Otherwise, leave SID unchanged and fail. */ + ptsid = 0; task_lock(p); - rcu_read_lock(); tracer = tracehook_tracer_task(p); - if (tracer != NULL) { - u32 ptsid = task_sid(tracer); - rcu_read_unlock(); - error = avc_has_perm_noaudit(ptsid, sid, - SECCLASS_PROCESS, - PROCESS__PTRACE, 0, &avd); - if (!error) - tsec->sid = sid; - task_unlock(p); - avc_audit(ptsid, sid, SECCLASS_PROCESS, - PROCESS__PTRACE, &avd, error, NULL); + if (tracer) + ptsid = task_sid(tracer); + task_unlock(p); + + if (tracer) { + error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, + PROCESS__PTRACE, NULL); if (error) - return error; - } else { - rcu_read_unlock(); - tsec->sid = sid; - task_unlock(p); + goto abort_change; } - } else - return -EINVAL; + tsec->sid = sid; + } else { + error = -EINVAL; + goto abort_change; + } + + commit_creds(new); return size; + +abort_change: + abort_creds(new); + return error; } static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) @@ -5471,23 +5473,21 @@ static void selinux_release_secctx(char *secdata, u32 seclen) #ifdef CONFIG_KEYS -static int selinux_key_alloc(struct key *k, struct task_struct *tsk, +static int selinux_key_alloc(struct key *k, const struct cred *cred, unsigned long flags) { - const struct task_security_struct *__tsec; + const struct task_security_struct *tsec; struct key_security_struct *ksec; ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); if (!ksec) return -ENOMEM; - rcu_read_lock(); - __tsec = __task_cred(tsk)->security; - if (__tsec->keycreate_sid) - ksec->sid = __tsec->keycreate_sid; + tsec = cred->security; + if (tsec->keycreate_sid) + ksec->sid = tsec->keycreate_sid; else - ksec->sid = __tsec->sid; - rcu_read_unlock(); + ksec->sid = tsec->sid; k->security = ksec; return 0; @@ -5502,8 +5502,8 @@ static void selinux_key_free(struct key *k) } static int selinux_key_permission(key_ref_t key_ref, - struct task_struct *ctx, - key_perm_t perm) + const struct cred *cred, + key_perm_t perm) { struct key *key; struct key_security_struct *ksec; @@ -5515,7 +5515,7 @@ static int selinux_key_permission(key_ref_t key_ref, if (perm == 0) return 0; - sid = task_sid(ctx); + sid = cred_sid(cred); key = key_ref_to_ptr(key_ref); ksec = key->security; @@ -5545,8 +5545,7 @@ static struct security_operations selinux_ops = { .ptrace_may_access = selinux_ptrace_may_access, .ptrace_traceme = selinux_ptrace_traceme, .capget = selinux_capget, - .capset_check = selinux_capset_check, - .capset_set = selinux_capset_set, + .capset = selinux_capset, .sysctl = selinux_sysctl, .capable = selinux_capable, .quotactl = selinux_quotactl, @@ -5621,10 +5620,11 @@ static struct security_operations selinux_ops = { .dentry_open = selinux_dentry_open, .task_create = selinux_task_create, - .cred_alloc_security = selinux_cred_alloc_security, .cred_free = selinux_cred_free, + .cred_prepare = selinux_cred_prepare, + .cred_commit = selinux_cred_commit, .task_setuid = selinux_task_setuid, - .task_post_setuid = selinux_task_post_setuid, + .task_fix_setuid = selinux_task_fix_setuid, .task_setgid = selinux_task_setgid, .task_setpgid = selinux_task_setpgid, .task_getpgid = selinux_task_getpgid, @@ -5641,7 +5641,6 @@ static struct security_operations selinux_ops = { .task_kill = selinux_task_kill, .task_wait = selinux_task_wait, .task_prctl = selinux_task_prctl, - .task_reparent_to_init = selinux_task_reparent_to_init, .task_to_inode = selinux_task_to_inode, .ipc_permission = selinux_ipc_permission, @@ -5737,8 +5736,6 @@ static struct security_operations selinux_ops = { static __init int selinux_init(void) { - struct task_security_struct *tsec; - if (!security_module_enable(&selinux_ops)) { selinux_enabled = 0; return 0; @@ -5752,10 +5749,7 @@ static __init int selinux_init(void) printk(KERN_INFO "SELinux: Initializing.\n"); /* Set the security state for the initial task. */ - if (cred_alloc_security(current->cred)) - panic("SELinux: Failed to initialize initial task.\n"); - tsec = current->cred->security; - tsec->osid = tsec->sid = SECINITSID_KERNEL; + cred_init_security(); sel_inode_cache = kmem_cache_create("selinux_inode_security", sizeof(struct inode_security_struct), diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 11167fd567b9..e952b397153d 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -104,8 +104,7 @@ static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode) if (rc != 0) return rc; - rc = smk_access(current->cred->security, ctp->cred->security, - MAY_READWRITE); + rc = smk_access(current_security(), task_security(ctp), MAY_READWRITE); if (rc != 0 && capable(CAP_MAC_OVERRIDE)) return 0; return rc; @@ -127,8 +126,7 @@ static int smack_ptrace_traceme(struct task_struct *ptp) if (rc != 0) return rc; - rc = smk_access(ptp->cred->security, current->cred->security, - MAY_READWRITE); + rc = smk_access(task_security(ptp), current_security(), MAY_READWRITE); if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE)) return 0; return rc; @@ -976,22 +974,6 @@ static int smack_file_receive(struct file *file) * Task hooks */ -/** - * smack_cred_alloc_security - "allocate" a task cred blob - * @cred: the task creds in need of a blob - * - * Smack isn't using copies of blobs. Everyone - * points to an immutable list. No alloc required. - * No data copy required. - * - * Always returns 0 - */ -static int smack_cred_alloc_security(struct cred *cred) -{ - cred->security = current_security(); - return 0; -} - /** * smack_cred_free - "free" task-level security credentials * @cred: the credentials in question @@ -1005,6 +987,30 @@ static void smack_cred_free(struct cred *cred) cred->security = NULL; } +/** + * smack_cred_prepare - prepare new set of credentials for modification + * @new: the new credentials + * @old: the original credentials + * @gfp: the atomicity of any memory allocations + * + * Prepare a new set of credentials for modification. + */ +static int smack_cred_prepare(struct cred *new, const struct cred *old, + gfp_t gfp) +{ + new->security = old->security; + return 0; +} + +/* + * commit new credentials + * @new: the new credentials + * @old: the original credentials + */ +static void smack_cred_commit(struct cred *new, const struct cred *old) +{ +} + /** * smack_task_setpgid - Smack check on setting pgid * @p: the task object @@ -2036,6 +2042,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value) static int smack_setprocattr(struct task_struct *p, char *name, void *value, size_t size) { + struct cred *new; char *newsmack; /* @@ -2058,7 +2065,11 @@ static int smack_setprocattr(struct task_struct *p, char *name, if (newsmack == NULL) return -EINVAL; - p->cred->security = newsmack; + new = prepare_creds(); + if (!new) + return -ENOMEM; + new->security = newsmack; + commit_creds(new); return size; } @@ -2354,17 +2365,17 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, /** * smack_key_alloc - Set the key security blob * @key: object - * @tsk: the task associated with the key + * @cred: the credentials to use * @flags: unused * * No allocation required * * Returns 0 */ -static int smack_key_alloc(struct key *key, struct task_struct *tsk, +static int smack_key_alloc(struct key *key, const struct cred *cred, unsigned long flags) { - key->security = tsk->cred->security; + key->security = cred->security; return 0; } @@ -2382,14 +2393,14 @@ static void smack_key_free(struct key *key) /* * smack_key_permission - Smack access on a key * @key_ref: gets to the object - * @context: task involved + * @cred: the credentials to use * @perm: unused * * Return 0 if the task has read and write to the object, * an error code otherwise */ static int smack_key_permission(key_ref_t key_ref, - struct task_struct *context, key_perm_t perm) + const struct cred *cred, key_perm_t perm) { struct key *keyp; @@ -2405,11 +2416,10 @@ static int smack_key_permission(key_ref_t key_ref, /* * This should not occur */ - if (context->cred->security == NULL) + if (cred->security == NULL) return -EACCES; - return smk_access(context->cred->security, keyp->security, - MAY_READWRITE); + return smk_access(cred->security, keyp->security, MAY_READWRITE); } #endif /* CONFIG_KEYS */ @@ -2580,8 +2590,7 @@ struct security_operations smack_ops = { .ptrace_may_access = smack_ptrace_may_access, .ptrace_traceme = smack_ptrace_traceme, .capget = cap_capget, - .capset_check = cap_capset_check, - .capset_set = cap_capset_set, + .capset = cap_capset, .capable = cap_capable, .syslog = smack_syslog, .settime = cap_settime, @@ -2630,9 +2639,10 @@ struct security_operations smack_ops = { .file_send_sigiotask = smack_file_send_sigiotask, .file_receive = smack_file_receive, - .cred_alloc_security = smack_cred_alloc_security, .cred_free = smack_cred_free, - .task_post_setuid = cap_task_post_setuid, + .cred_prepare = smack_cred_prepare, + .cred_commit = smack_cred_commit, + .task_fix_setuid = cap_task_fix_setuid, .task_setpgid = smack_task_setpgid, .task_getpgid = smack_task_getpgid, .task_getsid = smack_task_getsid, @@ -2645,7 +2655,6 @@ struct security_operations smack_ops = { .task_movememory = smack_task_movememory, .task_kill = smack_task_kill, .task_wait = smack_task_wait, - .task_reparent_to_init = cap_task_reparent_to_init, .task_to_inode = smack_task_to_inode, .task_prctl = cap_task_prctl, @@ -2721,6 +2730,8 @@ struct security_operations smack_ops = { */ static __init int smack_init(void) { + struct cred *cred; + if (!security_module_enable(&smack_ops)) return 0; @@ -2729,7 +2740,8 @@ static __init int smack_init(void) /* * Set the security state for the initial task. */ - current->cred->security = &smack_known_floor.smk_known; + cred = (struct cred *) current->cred; + cred->security = &smack_known_floor.smk_known; /* * Initialize locks -- cgit v1.2.3 From a6f76f23d297f70e2a6b3ec607f7aeeea9e37e8d Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:24 +1100 Subject: CRED: Make execve() take advantage of copy-on-write credentials Make execve() take advantage of copy-on-write credentials, allowing it to set up the credentials in advance, and then commit the whole lot after the point of no return. This patch and the preceding patches have been tested with the LTP SELinux testsuite. This patch makes several logical sets of alteration: (1) execve(). The credential bits from struct linux_binprm are, for the most part, replaced with a single credentials pointer (bprm->cred). This means that all the creds can be calculated in advance and then applied at the point of no return with no possibility of failure. I would like to replace bprm->cap_effective with: cap_isclear(bprm->cap_effective) but this seems impossible due to special behaviour for processes of pid 1 (they always retain their parent's capability masks where normally they'd be changed - see cap_bprm_set_creds()). The following sequence of events now happens: (a) At the start of do_execve, the current task's cred_exec_mutex is locked to prevent PTRACE_ATTACH from obsoleting the calculation of creds that we make. (a) prepare_exec_creds() is then called to make a copy of the current task's credentials and prepare it. This copy is then assigned to bprm->cred. This renders security_bprm_alloc() and security_bprm_free() unnecessary, and so they've been removed. (b) The determination of unsafe execution is now performed immediately after (a) rather than later on in the code. The result is stored in bprm->unsafe for future reference. (c) prepare_binprm() is called, possibly multiple times. (i) This applies the result of set[ug]id binaries to the new creds attached to bprm->cred. Personality bit clearance is recorded, but now deferred on the basis that the exec procedure may yet fail. (ii) This then calls the new security_bprm_set_creds(). This should calculate the new LSM and capability credentials into *bprm->cred. This folds together security_bprm_set() and parts of security_bprm_apply_creds() (these two have been removed). Anything that might fail must be done at this point. (iii) bprm->cred_prepared is set to 1. bprm->cred_prepared is 0 on the first pass of the security calculations, and 1 on all subsequent passes. This allows SELinux in (ii) to base its calculations only on the initial script and not on the interpreter. (d) flush_old_exec() is called to commit the task to execution. This performs the following steps with regard to credentials: (i) Clear pdeath_signal and set dumpable on certain circumstances that may not be covered by commit_creds(). (ii) Clear any bits in current->personality that were deferred from (c.i). (e) install_exec_creds() [compute_creds() as was] is called to install the new credentials. This performs the following steps with regard to credentials: (i) Calls security_bprm_committing_creds() to apply any security requirements, such as flushing unauthorised files in SELinux, that must be done before the credentials are changed. This is made up of bits of security_bprm_apply_creds() and security_bprm_post_apply_creds(), both of which have been removed. This function is not allowed to fail; anything that might fail must have been done in (c.ii). (ii) Calls commit_creds() to apply the new credentials in a single assignment (more or less). Possibly pdeath_signal and dumpable should be part of struct creds. (iii) Unlocks the task's cred_replace_mutex, thus allowing PTRACE_ATTACH to take place. (iv) Clears The bprm->cred pointer as the credentials it was holding are now immutable. (v) Calls security_bprm_committed_creds() to apply any security alterations that must be done after the creds have been changed. SELinux uses this to flush signals and signal handlers. (f) If an error occurs before (d.i), bprm_free() will call abort_creds() to destroy the proposed new credentials and will then unlock cred_replace_mutex. No changes to the credentials will have been made. (2) LSM interface. A number of functions have been changed, added or removed: (*) security_bprm_alloc(), ->bprm_alloc_security() (*) security_bprm_free(), ->bprm_free_security() Removed in favour of preparing new credentials and modifying those. (*) security_bprm_apply_creds(), ->bprm_apply_creds() (*) security_bprm_post_apply_creds(), ->bprm_post_apply_creds() Removed; split between security_bprm_set_creds(), security_bprm_committing_creds() and security_bprm_committed_creds(). (*) security_bprm_set(), ->bprm_set_security() Removed; folded into security_bprm_set_creds(). (*) security_bprm_set_creds(), ->bprm_set_creds() New. The new credentials in bprm->creds should be checked and set up as appropriate. bprm->cred_prepared is 0 on the first call, 1 on the second and subsequent calls. (*) security_bprm_committing_creds(), ->bprm_committing_creds() (*) security_bprm_committed_creds(), ->bprm_committed_creds() New. Apply the security effects of the new credentials. This includes closing unauthorised files in SELinux. This function may not fail. When the former is called, the creds haven't yet been applied to the process; when the latter is called, they have. The former may access bprm->cred, the latter may not. (3) SELinux. SELinux has a number of changes, in addition to those to support the LSM interface changes mentioned above: (a) The bprm_security_struct struct has been removed in favour of using the credentials-under-construction approach. (c) flush_unauthorized_files() now takes a cred pointer and passes it on to inode_has_perm(), file_has_perm() and dentry_open(). Signed-off-by: David Howells Acked-by: James Morris Acked-by: Serge Hallyn Signed-off-by: James Morris --- arch/x86/ia32/ia32_aout.c | 2 +- fs/binfmt_aout.c | 2 +- fs/binfmt_elf.c | 2 +- fs/binfmt_elf_fdpic.c | 2 +- fs/binfmt_flat.c | 2 +- fs/binfmt_som.c | 2 +- fs/compat.c | 42 +++--- fs/exec.c | 149 +++++++++++--------- fs/internal.h | 6 + include/linux/audit.h | 16 --- include/linux/binfmts.h | 16 ++- include/linux/cred.h | 3 +- include/linux/key.h | 2 - include/linux/security.h | 103 +++++--------- kernel/cred.c | 46 ++++++- security/capability.c | 19 +-- security/commoncap.c | 152 ++++++++++---------- security/keys/process_keys.c | 42 ------ security/root_plug.c | 13 +- security/security.c | 26 ++-- security/selinux/hooks.c | 283 ++++++++++++++++---------------------- security/selinux/include/objsec.h | 11 -- security/smack/smack_lsm.c | 3 +- 23 files changed, 429 insertions(+), 515 deletions(-) (limited to 'include') diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c index 127ec3f07214..2a4d073d2cf1 100644 --- a/arch/x86/ia32/ia32_aout.c +++ b/arch/x86/ia32/ia32_aout.c @@ -327,7 +327,7 @@ static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs) current->mm->cached_hole_size = 0; current->mm->mmap = NULL; - compute_creds(bprm); + install_exec_creds(bprm); current->flags &= ~PF_FORKNOEXEC; if (N_MAGIC(ex) == OMAGIC) { diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c index 204cfd1d7676..f1f3f4192a60 100644 --- a/fs/binfmt_aout.c +++ b/fs/binfmt_aout.c @@ -320,7 +320,7 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs) current->mm->free_area_cache = current->mm->mmap_base; current->mm->cached_hole_size = 0; - compute_creds(bprm); + install_exec_creds(bprm); current->flags &= ~PF_FORKNOEXEC; #ifdef __sparc__ if (N_MAGIC(ex) == NMAGIC) { diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 9142ff5dc8e6..f458c1217c5e 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -956,7 +956,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) } #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ - compute_creds(bprm); + install_exec_creds(bprm); current->flags &= ~PF_FORKNOEXEC; retval = create_elf_tables(bprm, &loc->elf_ex, load_addr, interp_load_addr); diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 45dabd59936f..aa5b43205e37 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -404,7 +404,7 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm, current->mm->start_stack = current->mm->start_brk + stack_size; #endif - compute_creds(bprm); + install_exec_creds(bprm); current->flags &= ~PF_FORKNOEXEC; if (create_elf_fdpic_tables(bprm, current->mm, &exec_params, &interp_params) < 0) diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index ccb781a6a804..7bbd5c6b3725 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -880,7 +880,7 @@ static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) (libinfo.lib_list[j].loaded)? libinfo.lib_list[j].start_data:UNLOADED_LIB; - compute_creds(bprm); + install_exec_creds(bprm); current->flags &= ~PF_FORKNOEXEC; set_binfmt(&flat_format); diff --git a/fs/binfmt_som.c b/fs/binfmt_som.c index 74e587a52796..08644a61616e 100644 --- a/fs/binfmt_som.c +++ b/fs/binfmt_som.c @@ -255,7 +255,7 @@ load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs) kfree(hpuxhdr); set_binfmt(&som_format); - compute_creds(bprm); + install_exec_creds(bprm); setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT); create_som_tables(bprm); diff --git a/fs/compat.c b/fs/compat.c index e5f49f538502..d1ece79b6411 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -1393,10 +1393,20 @@ int compat_do_execve(char * filename, if (!bprm) goto out_ret; + retval = mutex_lock_interruptible(¤t->cred_exec_mutex); + if (retval < 0) + goto out_free; + + retval = -ENOMEM; + bprm->cred = prepare_exec_creds(); + if (!bprm->cred) + goto out_unlock; + check_unsafe_exec(bprm); + file = open_exec(filename); retval = PTR_ERR(file); if (IS_ERR(file)) - goto out_kfree; + goto out_unlock; sched_exec(); @@ -1410,14 +1420,10 @@ int compat_do_execve(char * filename, bprm->argc = compat_count(argv, MAX_ARG_STRINGS); if ((retval = bprm->argc) < 0) - goto out_mm; + goto out; bprm->envc = compat_count(envp, MAX_ARG_STRINGS); if ((retval = bprm->envc) < 0) - goto out_mm; - - retval = security_bprm_alloc(bprm); - if (retval) goto out; retval = prepare_binprm(bprm); @@ -1438,19 +1444,16 @@ int compat_do_execve(char * filename, goto out; retval = search_binary_handler(bprm, regs); - if (retval >= 0) { - /* execve success */ - security_bprm_free(bprm); - acct_update_integrals(current); - free_bprm(bprm); - return retval; - } + if (retval < 0) + goto out; -out: - if (bprm->security) - security_bprm_free(bprm); + /* execve succeeded */ + mutex_unlock(¤t->cred_exec_mutex); + acct_update_integrals(current); + free_bprm(bprm); + return retval; -out_mm: +out: if (bprm->mm) mmput(bprm->mm); @@ -1460,7 +1463,10 @@ out_file: fput(bprm->file); } -out_kfree: +out_unlock: + mutex_unlock(¤t->cred_exec_mutex); + +out_free: free_bprm(bprm); out_ret: diff --git a/fs/exec.c b/fs/exec.c index 9bd3559ddece..32f13e299417 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -55,6 +55,7 @@ #include #include #include +#include "internal.h" #ifdef __alpha__ /* for /sbin/loader handling in search_binary_handler() */ @@ -1007,15 +1008,17 @@ int flush_old_exec(struct linux_binprm * bprm) */ current->mm->task_size = TASK_SIZE; - if (bprm->e_uid != current_euid() || - bprm->e_gid != current_egid()) { - set_dumpable(current->mm, suid_dumpable); + /* install the new credentials */ + if (bprm->cred->uid != current_euid() || + bprm->cred->gid != current_egid()) { current->pdeath_signal = 0; } else if (file_permission(bprm->file, MAY_READ) || - (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) { + bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) { set_dumpable(current->mm, suid_dumpable); } + current->personality &= ~bprm->per_clear; + /* An exec changes our domain. We are no longer part of the thread group */ @@ -1032,13 +1035,50 @@ out: EXPORT_SYMBOL(flush_old_exec); +/* + * install the new credentials for this executable + */ +void install_exec_creds(struct linux_binprm *bprm) +{ + security_bprm_committing_creds(bprm); + + commit_creds(bprm->cred); + bprm->cred = NULL; + + /* cred_exec_mutex must be held at least to this point to prevent + * ptrace_attach() from altering our determination of the task's + * credentials; any time after this it may be unlocked */ + + security_bprm_committed_creds(bprm); +} +EXPORT_SYMBOL(install_exec_creds); + +/* + * determine how safe it is to execute the proposed program + * - the caller must hold current->cred_exec_mutex to protect against + * PTRACE_ATTACH + */ +void check_unsafe_exec(struct linux_binprm *bprm) +{ + struct task_struct *p = current; + + bprm->unsafe = tracehook_unsafe_exec(p); + + if (atomic_read(&p->fs->count) > 1 || + atomic_read(&p->files->count) > 1 || + atomic_read(&p->sighand->count) > 1) + bprm->unsafe |= LSM_UNSAFE_SHARE; +} + /* * Fill the binprm structure from the inode. * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes + * + * This may be called multiple times for binary chains (scripts for example). */ int prepare_binprm(struct linux_binprm *bprm) { - int mode; + umode_t mode; struct inode * inode = bprm->file->f_path.dentry->d_inode; int retval; @@ -1046,14 +1086,15 @@ int prepare_binprm(struct linux_binprm *bprm) if (bprm->file->f_op == NULL) return -EACCES; - bprm->e_uid = current_euid(); - bprm->e_gid = current_egid(); + /* clear any previous set[ug]id data from a previous binary */ + bprm->cred->euid = current_euid(); + bprm->cred->egid = current_egid(); - if(!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { + if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { /* Set-uid? */ if (mode & S_ISUID) { - current->personality &= ~PER_CLEAR_ON_SETID; - bprm->e_uid = inode->i_uid; + bprm->per_clear |= PER_CLEAR_ON_SETID; + bprm->cred->euid = inode->i_uid; } /* Set-gid? */ @@ -1063,50 +1104,23 @@ int prepare_binprm(struct linux_binprm *bprm) * executable. */ if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { - current->personality &= ~PER_CLEAR_ON_SETID; - bprm->e_gid = inode->i_gid; + bprm->per_clear |= PER_CLEAR_ON_SETID; + bprm->cred->egid = inode->i_gid; } } /* fill in binprm security blob */ - retval = security_bprm_set(bprm); + retval = security_bprm_set_creds(bprm); if (retval) return retval; + bprm->cred_prepared = 1; - memset(bprm->buf,0,BINPRM_BUF_SIZE); - return kernel_read(bprm->file,0,bprm->buf,BINPRM_BUF_SIZE); + memset(bprm->buf, 0, BINPRM_BUF_SIZE); + return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); } EXPORT_SYMBOL(prepare_binprm); -static int unsafe_exec(struct task_struct *p) -{ - int unsafe = tracehook_unsafe_exec(p); - - if (atomic_read(&p->fs->count) > 1 || - atomic_read(&p->files->count) > 1 || - atomic_read(&p->sighand->count) > 1) - unsafe |= LSM_UNSAFE_SHARE; - - return unsafe; -} - -void compute_creds(struct linux_binprm *bprm) -{ - int unsafe; - - if (bprm->e_uid != current_uid()) - current->pdeath_signal = 0; - exec_keys(current); - - task_lock(current); - unsafe = unsafe_exec(current); - security_bprm_apply_creds(bprm, unsafe); - task_unlock(current); - security_bprm_post_apply_creds(bprm); -} -EXPORT_SYMBOL(compute_creds); - /* * Arguments are '\0' separated strings found at the location bprm->p * points to; chop off the first by relocating brpm->p to right after @@ -1259,6 +1273,8 @@ EXPORT_SYMBOL(search_binary_handler); void free_bprm(struct linux_binprm *bprm) { free_arg_pages(bprm); + if (bprm->cred) + abort_creds(bprm->cred); kfree(bprm); } @@ -1284,10 +1300,20 @@ int do_execve(char * filename, if (!bprm) goto out_files; + retval = mutex_lock_interruptible(¤t->cred_exec_mutex); + if (retval < 0) + goto out_free; + + retval = -ENOMEM; + bprm->cred = prepare_exec_creds(); + if (!bprm->cred) + goto out_unlock; + check_unsafe_exec(bprm); + file = open_exec(filename); retval = PTR_ERR(file); if (IS_ERR(file)) - goto out_kfree; + goto out_unlock; sched_exec(); @@ -1301,14 +1327,10 @@ int do_execve(char * filename, bprm->argc = count(argv, MAX_ARG_STRINGS); if ((retval = bprm->argc) < 0) - goto out_mm; + goto out; bprm->envc = count(envp, MAX_ARG_STRINGS); if ((retval = bprm->envc) < 0) - goto out_mm; - - retval = security_bprm_alloc(bprm); - if (retval) goto out; retval = prepare_binprm(bprm); @@ -1330,21 +1352,18 @@ int do_execve(char * filename, current->flags &= ~PF_KTHREAD; retval = search_binary_handler(bprm,regs); - if (retval >= 0) { - /* execve success */ - security_bprm_free(bprm); - acct_update_integrals(current); - free_bprm(bprm); - if (displaced) - put_files_struct(displaced); - return retval; - } + if (retval < 0) + goto out; -out: - if (bprm->security) - security_bprm_free(bprm); + /* execve succeeded */ + mutex_unlock(¤t->cred_exec_mutex); + acct_update_integrals(current); + free_bprm(bprm); + if (displaced) + put_files_struct(displaced); + return retval; -out_mm: +out: if (bprm->mm) mmput (bprm->mm); @@ -1353,7 +1372,11 @@ out_file: allow_write_access(bprm->file); fput(bprm->file); } -out_kfree: + +out_unlock: + mutex_unlock(¤t->cred_exec_mutex); + +out_free: free_bprm(bprm); out_files: diff --git a/fs/internal.h b/fs/internal.h index 80aa9a023372..53af885f1732 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -10,6 +10,7 @@ */ struct super_block; +struct linux_binprm; /* * block_dev.c @@ -39,6 +40,11 @@ static inline int sb_is_blkdev_sb(struct super_block *sb) */ extern void __init chrdev_init(void); +/* + * exec.c + */ +extern void check_unsafe_exec(struct linux_binprm *); + /* * namespace.c */ diff --git a/include/linux/audit.h b/include/linux/audit.h index 0b2fcb698a63..e8ce2c4c7ac7 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -508,22 +508,6 @@ static inline int audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat) return 0; } -/* - * ieieeeeee, an audit function without a return code! - * - * This function might fail! I decided that it didn't matter. We are too late - * to fail the syscall and the information isn't REQUIRED for any purpose. It's - * just nice to have. We should be able to look at past audit logs to figure - * out this process's current cap set along with the fcaps from the PATH record - * and use that to come up with the final set. Yeah, its ugly, but all the info - * is still in the audit log. So I'm not going to bother mentioning we failed - * if we couldn't allocate memory. - * - * If someone changes their mind they could create the aux record earlier and - * then search here and use that earlier allocation. But I don't wanna. - * - * -Eric - */ static inline int audit_log_bprm_fcaps(struct linux_binprm *bprm, const struct cred *new, const struct cred *old) diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 7394b5b349ff..6cbfbe297180 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -35,16 +35,20 @@ struct linux_binprm{ struct mm_struct *mm; unsigned long p; /* current top of mem */ unsigned int sh_bang:1, - misc_bang:1; + misc_bang:1, + cred_prepared:1,/* true if creds already prepared (multiple + * preps happen for interpreters) */ + cap_effective:1;/* true if has elevated effective capabilities, + * false if not; except for init which inherits + * its parent's caps anyway */ #ifdef __alpha__ unsigned int taso:1; #endif unsigned int recursion_depth; struct file * file; - int e_uid, e_gid; - kernel_cap_t cap_post_exec_permitted; - bool cap_effective; - void *security; + struct cred *cred; /* new credentials */ + int unsafe; /* how unsafe this exec is (mask of LSM_UNSAFE_*) */ + unsigned int per_clear; /* bits to clear in current->personality */ int argc, envc; char * filename; /* Name of binary as seen by procps */ char * interp; /* Name of the binary really executed. Most @@ -101,7 +105,7 @@ extern int setup_arg_pages(struct linux_binprm * bprm, int executable_stack); extern int bprm_mm_init(struct linux_binprm *bprm); extern int copy_strings_kernel(int argc,char ** argv,struct linux_binprm *bprm); -extern void compute_creds(struct linux_binprm *binprm); +extern void install_exec_creds(struct linux_binprm *bprm); extern int do_coredump(long signr, int exit_code, struct pt_regs * regs); extern int set_binfmt(struct linux_binfmt *new); extern void free_bprm(struct linux_binprm *); diff --git a/include/linux/cred.h b/include/linux/cred.h index eaf6fa695a04..8edb4d1d5427 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -84,8 +84,6 @@ struct thread_group_cred { struct key *process_keyring; /* keyring private to this process */ struct rcu_head rcu; /* RCU deletion hook */ }; - -extern void release_tgcred(struct cred *cred); #endif /* @@ -144,6 +142,7 @@ struct cred { extern void __put_cred(struct cred *); extern int copy_creds(struct task_struct *, unsigned long); extern struct cred *prepare_creds(void); +extern struct cred *prepare_exec_creds(void); extern struct cred *prepare_usermodehelper_creds(void); extern int commit_creds(struct cred *); extern void abort_creds(struct cred *); diff --git a/include/linux/key.h b/include/linux/key.h index 69ecf0934b02..21d32a142c00 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -278,7 +278,6 @@ extern ctl_table key_sysctls[]; * the userspace interface */ extern int install_thread_keyring_to_cred(struct cred *cred); -extern int exec_keys(struct task_struct *tsk); extern void key_fsuid_changed(struct task_struct *tsk); extern void key_fsgid_changed(struct task_struct *tsk); extern void key_init(void); @@ -294,7 +293,6 @@ extern void key_init(void); #define make_key_ref(k, p) NULL #define key_ref_to_ptr(k) NULL #define is_key_possessed(k) 0 -#define exec_keys(t) do { } while(0) #define key_fsuid_changed(t) do { } while(0) #define key_fsgid_changed(t) do { } while(0) #define key_init() do { } while(0) diff --git a/include/linux/security.h b/include/linux/security.h index 68be11251447..56a0eed65673 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -57,8 +57,7 @@ extern int cap_capset(struct cred *new, const struct cred *old, const kernel_cap_t *effective, const kernel_cap_t *inheritable, const kernel_cap_t *permitted); -extern int cap_bprm_set_security(struct linux_binprm *bprm); -extern int cap_bprm_apply_creds(struct linux_binprm *bprm, int unsafe); +extern int cap_bprm_set_creds(struct linux_binprm *bprm); extern int cap_bprm_secureexec(struct linux_binprm *bprm); extern int cap_inode_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags); @@ -110,7 +109,7 @@ extern unsigned long mmap_min_addr; struct sched_param; struct request_sock; -/* bprm_apply_creds unsafe reasons */ +/* bprm->unsafe reasons */ #define LSM_UNSAFE_SHARE 1 #define LSM_UNSAFE_PTRACE 2 #define LSM_UNSAFE_PTRACE_CAP 4 @@ -154,36 +153,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * * Security hooks for program execution operations. * - * @bprm_alloc_security: - * Allocate and attach a security structure to the @bprm->security field. - * The security field is initialized to NULL when the bprm structure is - * allocated. - * @bprm contains the linux_binprm structure to be modified. - * Return 0 if operation was successful. - * @bprm_free_security: - * @bprm contains the linux_binprm structure to be modified. - * Deallocate and clear the @bprm->security field. - * @bprm_apply_creds: - * Compute and set the security attributes of a process being transformed - * by an execve operation based on the old attributes (current->security) - * and the information saved in @bprm->security by the set_security hook. - * Since this function may return an error, in which case the process will - * be killed. However, it can leave the security attributes of the - * process unchanged if an access failure occurs at this point. - * bprm_apply_creds is called under task_lock. @unsafe indicates various - * reasons why it may be unsafe to change security state. - * @bprm contains the linux_binprm structure. - * @bprm_post_apply_creds: - * Runs after bprm_apply_creds with the task_lock dropped, so that - * functions which cannot be called safely under the task_lock can - * be used. This hook is a good place to perform state changes on - * the process such as closing open file descriptors to which access - * is no longer granted if the attributes were changed. - * Note that a security module might need to save state between - * bprm_apply_creds and bprm_post_apply_creds to store the decision - * on whether the process may proceed. - * @bprm contains the linux_binprm structure. - * @bprm_set_security: + * @bprm_set_creds: * Save security information in the bprm->security field, typically based * on information about the bprm->file, for later use by the apply_creds * hook. This hook may also optionally check permissions (e.g. for @@ -196,15 +166,30 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @bprm contains the linux_binprm structure. * Return 0 if the hook is successful and permission is granted. * @bprm_check_security: - * This hook mediates the point when a search for a binary handler will - * begin. It allows a check the @bprm->security value which is set in - * the preceding set_security call. The primary difference from - * set_security is that the argv list and envp list are reliably - * available in @bprm. This hook may be called multiple times - * during a single execve; and in each pass set_security is called - * first. + * This hook mediates the point when a search for a binary handler will + * begin. It allows a check the @bprm->security value which is set in the + * preceding set_creds call. The primary difference from set_creds is + * that the argv list and envp list are reliably available in @bprm. This + * hook may be called multiple times during a single execve; and in each + * pass set_creds is called first. * @bprm contains the linux_binprm structure. * Return 0 if the hook is successful and permission is granted. + * @bprm_committing_creds: + * Prepare to install the new security attributes of a process being + * transformed by an execve operation, based on the old credentials + * pointed to by @current->cred and the information set in @bprm->cred by + * the bprm_set_creds hook. @bprm points to the linux_binprm structure. + * This hook is a good place to perform state changes on the process such + * as closing open file descriptors to which access will no longer be + * granted when the attributes are changed. This is called immediately + * before commit_creds(). + * @bprm_committed_creds: + * Tidy up after the installation of the new security attributes of a + * process being transformed by an execve operation. The new credentials + * have, by this point, been set to @current->cred. @bprm points to the + * linux_binprm structure. This hook is a good place to perform state + * changes on the process such as clearing out non-inheritable signal + * state. This is called immediately after commit_creds(). * @bprm_secureexec: * Return a boolean value (0 or 1) indicating whether a "secure exec" * is required. The flag is passed in the auxiliary table @@ -1301,13 +1286,11 @@ struct security_operations { int (*settime) (struct timespec *ts, struct timezone *tz); int (*vm_enough_memory) (struct mm_struct *mm, long pages); - int (*bprm_alloc_security) (struct linux_binprm *bprm); - void (*bprm_free_security) (struct linux_binprm *bprm); - int (*bprm_apply_creds) (struct linux_binprm *bprm, int unsafe); - void (*bprm_post_apply_creds) (struct linux_binprm *bprm); - int (*bprm_set_security) (struct linux_binprm *bprm); + int (*bprm_set_creds) (struct linux_binprm *bprm); int (*bprm_check_security) (struct linux_binprm *bprm); int (*bprm_secureexec) (struct linux_binprm *bprm); + void (*bprm_committing_creds) (struct linux_binprm *bprm); + void (*bprm_committed_creds) (struct linux_binprm *bprm); int (*sb_alloc_security) (struct super_block *sb); void (*sb_free_security) (struct super_block *sb); @@ -1569,12 +1552,10 @@ int security_settime(struct timespec *ts, struct timezone *tz); int security_vm_enough_memory(long pages); int security_vm_enough_memory_mm(struct mm_struct *mm, long pages); int security_vm_enough_memory_kern(long pages); -int security_bprm_alloc(struct linux_binprm *bprm); -void security_bprm_free(struct linux_binprm *bprm); -int security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe); -void security_bprm_post_apply_creds(struct linux_binprm *bprm); -int security_bprm_set(struct linux_binprm *bprm); +int security_bprm_set_creds(struct linux_binprm *bprm); int security_bprm_check(struct linux_binprm *bprm); +void security_bprm_committing_creds(struct linux_binprm *bprm); +void security_bprm_committed_creds(struct linux_binprm *bprm); int security_bprm_secureexec(struct linux_binprm *bprm); int security_sb_alloc(struct super_block *sb); void security_sb_free(struct super_block *sb); @@ -1812,32 +1793,22 @@ static inline int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) return cap_vm_enough_memory(mm, pages); } -static inline int security_bprm_alloc(struct linux_binprm *bprm) -{ - return 0; -} - -static inline void security_bprm_free(struct linux_binprm *bprm) -{ } - -static inline int security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) +static inline int security_bprm_set_creds(struct linux_binprm *bprm) { - return cap_bprm_apply_creds(bprm, unsafe); + return cap_bprm_set_creds(bprm); } -static inline void security_bprm_post_apply_creds(struct linux_binprm *bprm) +static inline int security_bprm_check(struct linux_binprm *bprm) { - return; + return 0; } -static inline int security_bprm_set(struct linux_binprm *bprm) +static inline void security_bprm_committing_creds(struct linux_binprm *bprm) { - return cap_bprm_set_security(bprm); } -static inline int security_bprm_check(struct linux_binprm *bprm) +static inline void security_bprm_committed_creds(struct linux_binprm *bprm) { - return 0; } static inline int security_bprm_secureexec(struct linux_binprm *bprm) diff --git a/kernel/cred.c b/kernel/cred.c index cb6b5eda978d..e6fcdd67b2ec 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -68,7 +68,7 @@ static void release_tgcred_rcu(struct rcu_head *rcu) /* * Release a set of thread group credentials. */ -void release_tgcred(struct cred *cred) +static void release_tgcred(struct cred *cred) { #ifdef CONFIG_KEYS struct thread_group_cred *tgcred = cred->tgcred; @@ -163,6 +163,50 @@ error: } EXPORT_SYMBOL(prepare_creds); +/* + * Prepare credentials for current to perform an execve() + * - The caller must hold current->cred_exec_mutex + */ +struct cred *prepare_exec_creds(void) +{ + struct thread_group_cred *tgcred = NULL; + struct cred *new; + +#ifdef CONFIG_KEYS + tgcred = kmalloc(sizeof(*tgcred), GFP_KERNEL); + if (!tgcred) + return NULL; +#endif + + new = prepare_creds(); + if (!new) { + kfree(tgcred); + return new; + } + +#ifdef CONFIG_KEYS + /* newly exec'd tasks don't get a thread keyring */ + key_put(new->thread_keyring); + new->thread_keyring = NULL; + + /* create a new per-thread-group creds for all this set of threads to + * share */ + memcpy(tgcred, new->tgcred, sizeof(struct thread_group_cred)); + + atomic_set(&tgcred->usage, 1); + spin_lock_init(&tgcred->lock); + + /* inherit the session keyring; new process keyring */ + key_get(tgcred->session_keyring); + tgcred->process_keyring = NULL; + + release_tgcred(new); + new->tgcred = tgcred; +#endif + + return new; +} + /* * prepare new credentials for the usermode helper dispatcher */ diff --git a/security/capability.c b/security/capability.c index efeb6d9e0e6a..185804f99ad1 100644 --- a/security/capability.c +++ b/security/capability.c @@ -32,24 +32,19 @@ static int cap_quota_on(struct dentry *dentry) return 0; } -static int cap_bprm_alloc_security(struct linux_binprm *bprm) +static int cap_bprm_check_security (struct linux_binprm *bprm) { return 0; } -static void cap_bprm_free_security(struct linux_binprm *bprm) +static void cap_bprm_committing_creds(struct linux_binprm *bprm) { } -static void cap_bprm_post_apply_creds(struct linux_binprm *bprm) +static void cap_bprm_committed_creds(struct linux_binprm *bprm) { } -static int cap_bprm_check_security(struct linux_binprm *bprm) -{ - return 0; -} - static int cap_sb_alloc_security(struct super_block *sb) { return 0; @@ -827,11 +822,9 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, syslog); set_to_cap_if_null(ops, settime); set_to_cap_if_null(ops, vm_enough_memory); - set_to_cap_if_null(ops, bprm_alloc_security); - set_to_cap_if_null(ops, bprm_free_security); - set_to_cap_if_null(ops, bprm_apply_creds); - set_to_cap_if_null(ops, bprm_post_apply_creds); - set_to_cap_if_null(ops, bprm_set_security); + set_to_cap_if_null(ops, bprm_set_creds); + set_to_cap_if_null(ops, bprm_committing_creds); + set_to_cap_if_null(ops, bprm_committed_creds); set_to_cap_if_null(ops, bprm_check_security); set_to_cap_if_null(ops, bprm_secureexec); set_to_cap_if_null(ops, sb_alloc_security); diff --git a/security/commoncap.c b/security/commoncap.c index b5419273f92d..51dfa11e8e56 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -167,7 +167,7 @@ int cap_capset(struct cred *new, static inline void bprm_clear_caps(struct linux_binprm *bprm) { - cap_clear(bprm->cap_post_exec_permitted); + cap_clear(bprm->cred->cap_permitted); bprm->cap_effective = false; } @@ -198,15 +198,15 @@ int cap_inode_killpriv(struct dentry *dentry) } static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, - struct linux_binprm *bprm) + struct linux_binprm *bprm, + bool *effective) { + struct cred *new = bprm->cred; unsigned i; int ret = 0; if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE) - bprm->cap_effective = true; - else - bprm->cap_effective = false; + *effective = true; CAP_FOR_EACH_U32(i) { __u32 permitted = caps->permitted.cap[i]; @@ -215,16 +215,13 @@ static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, /* * pP' = (X & fP) | (pI & fI) */ - bprm->cap_post_exec_permitted.cap[i] = - (current->cred->cap_bset.cap[i] & permitted) | - (current->cred->cap_inheritable.cap[i] & inheritable); + new->cap_permitted.cap[i] = + (new->cap_bset.cap[i] & permitted) | + (new->cap_inheritable.cap[i] & inheritable); - if (permitted & ~bprm->cap_post_exec_permitted.cap[i]) { - /* - * insufficient to execute correctly - */ + if (permitted & ~new->cap_permitted.cap[i]) + /* insufficient to execute correctly */ ret = -EPERM; - } } /* @@ -232,7 +229,7 @@ static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, * do not have enough capabilities, we return an error if they are * missing some "forced" (aka file-permitted) capabilities. */ - return bprm->cap_effective ? ret : 0; + return *effective ? ret : 0; } int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps) @@ -250,10 +247,9 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps, XATTR_CAPS_SZ); - if (size == -ENODATA || size == -EOPNOTSUPP) { + if (size == -ENODATA || size == -EOPNOTSUPP) /* no data, that's ok */ return -ENODATA; - } if (size < 0) return size; @@ -262,7 +258,7 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc); - switch ((magic_etc & VFS_CAP_REVISION_MASK)) { + switch (magic_etc & VFS_CAP_REVISION_MASK) { case VFS_CAP_REVISION_1: if (size != XATTR_CAPS_SZ_1) return -EINVAL; @@ -283,11 +279,12 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data cpu_caps->permitted.cap[i] = le32_to_cpu(caps.data[i].permitted); cpu_caps->inheritable.cap[i] = le32_to_cpu(caps.data[i].inheritable); } + return 0; } /* Locate any VFS capabilities: */ -static int get_file_caps(struct linux_binprm *bprm) +static int get_file_caps(struct linux_binprm *bprm, bool *effective) { struct dentry *dentry; int rc = 0; @@ -313,7 +310,10 @@ static int get_file_caps(struct linux_binprm *bprm) goto out; } - rc = bprm_caps_from_vfs_caps(&vcaps, bprm); + rc = bprm_caps_from_vfs_caps(&vcaps, bprm, effective); + if (rc == -EINVAL) + printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n", + __func__, rc, bprm->filename); out: dput(dentry); @@ -334,18 +334,27 @@ int cap_inode_killpriv(struct dentry *dentry) return 0; } -static inline int get_file_caps(struct linux_binprm *bprm) +static inline int get_file_caps(struct linux_binprm *bprm, bool *effective) { bprm_clear_caps(bprm); return 0; } #endif -int cap_bprm_set_security (struct linux_binprm *bprm) +/* + * set up the new credentials for an exec'd task + */ +int cap_bprm_set_creds(struct linux_binprm *bprm) { + const struct cred *old = current_cred(); + struct cred *new = bprm->cred; + bool effective; int ret; - ret = get_file_caps(bprm); + effective = false; + ret = get_file_caps(bprm, &effective); + if (ret < 0) + return ret; if (!issecure(SECURE_NOROOT)) { /* @@ -353,63 +362,47 @@ int cap_bprm_set_security (struct linux_binprm *bprm) * executables under compatibility mode, we override the * capability sets for the file. * - * If only the real uid is 0, we do not set the effective - * bit. + * If only the real uid is 0, we do not set the effective bit. */ - if (bprm->e_uid == 0 || current_uid() == 0) { + if (new->euid == 0 || new->uid == 0) { /* pP' = (cap_bset & ~0) | (pI & ~0) */ - bprm->cap_post_exec_permitted = cap_combine( - current->cred->cap_bset, - current->cred->cap_inheritable); - bprm->cap_effective = (bprm->e_uid == 0); - ret = 0; + new->cap_permitted = cap_combine(old->cap_bset, + old->cap_inheritable); } + if (new->euid == 0) + effective = true; } - return ret; -} - -int cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) -{ - const struct cred *old = current_cred(); - struct cred *new; - - new = prepare_creds(); - if (!new) - return -ENOMEM; - - if (bprm->e_uid != old->uid || bprm->e_gid != old->gid || - !cap_issubset(bprm->cap_post_exec_permitted, - old->cap_permitted)) { - set_dumpable(current->mm, suid_dumpable); - current->pdeath_signal = 0; - - if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) { - if (!capable(CAP_SETUID)) { - bprm->e_uid = old->uid; - bprm->e_gid = old->gid; - } - if (cap_limit_ptraced_target()) { - bprm->cap_post_exec_permitted = cap_intersect( - bprm->cap_post_exec_permitted, - new->cap_permitted); - } + /* Don't let someone trace a set[ug]id/setpcap binary with the revised + * credentials unless they have the appropriate permit + */ + if ((new->euid != old->uid || + new->egid != old->gid || + !cap_issubset(new->cap_permitted, old->cap_permitted)) && + bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) { + /* downgrade; they get no more than they had, and maybe less */ + if (!capable(CAP_SETUID)) { + new->euid = new->uid; + new->egid = new->gid; } + if (cap_limit_ptraced_target()) + new->cap_permitted = cap_intersect(new->cap_permitted, + old->cap_permitted); } - new->suid = new->euid = new->fsuid = bprm->e_uid; - new->sgid = new->egid = new->fsgid = bprm->e_gid; + new->suid = new->fsuid = new->euid; + new->sgid = new->fsgid = new->egid; - /* For init, we want to retain the capabilities set - * in the init_task struct. Thus we skip the usual - * capability rules */ + /* For init, we want to retain the capabilities set in the initial + * task. Thus we skip the usual capability rules + */ if (!is_global_init(current)) { - new->cap_permitted = bprm->cap_post_exec_permitted; - if (bprm->cap_effective) - new->cap_effective = bprm->cap_post_exec_permitted; + if (effective) + new->cap_effective = new->cap_permitted; else cap_clear(new->cap_effective); } + bprm->cap_effective = effective; /* * Audit candidate if current->cap_effective is set @@ -425,23 +418,31 @@ int cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) */ if (!cap_isclear(new->cap_effective)) { if (!cap_issubset(CAP_FULL_SET, new->cap_effective) || - bprm->e_uid != 0 || new->uid != 0 || - issecure(SECURE_NOROOT)) - audit_log_bprm_fcaps(bprm, new, old); + new->euid != 0 || new->uid != 0 || + issecure(SECURE_NOROOT)) { + ret = audit_log_bprm_fcaps(bprm, new, old); + if (ret < 0) + return ret; + } } new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); - return commit_creds(new); + return 0; } -int cap_bprm_secureexec (struct linux_binprm *bprm) +/* + * determine whether a secure execution is required + * - the creds have been committed at this point, and are no longer available + * through bprm + */ +int cap_bprm_secureexec(struct linux_binprm *bprm) { const struct cred *cred = current_cred(); if (cred->uid != 0) { if (bprm->cap_effective) return 1; - if (!cap_isclear(bprm->cap_post_exec_permitted)) + if (!cap_isclear(cred->cap_permitted)) return 1; } @@ -477,7 +478,7 @@ int cap_inode_removexattr(struct dentry *dentry, const char *name) } /* moved from kernel/sys.c. */ -/* +/* * cap_emulate_setxuid() fixes the effective / permitted capabilities of * a process after a call to setuid, setreuid, or setresuid. * @@ -491,10 +492,10 @@ int cap_inode_removexattr(struct dentry *dentry, const char *name) * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective * capabilities are set to the permitted capabilities. * - * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should + * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should * never happen. * - * -astor + * -astor * * cevans - New behaviour, Oct '99 * A process may, via prctl(), elect to keep its capabilities when it @@ -751,4 +752,3 @@ int cap_vm_enough_memory(struct mm_struct *mm, long pages) cap_sys_admin = 1; return __vm_enough_memory(mm, pages, cap_sys_admin); } - diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index df329f684a65..2f5d89e92b85 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -274,48 +274,6 @@ static int install_session_keyring(struct key *keyring) return commit_creds(new); } -/*****************************************************************************/ -/* - * deal with execve() - */ -int exec_keys(struct task_struct *tsk) -{ - struct thread_group_cred *tgcred = NULL; - struct cred *new; - -#ifdef CONFIG_KEYS - tgcred = kmalloc(sizeof(*tgcred), GFP_KERNEL); - if (!tgcred) - return -ENOMEM; -#endif - - new = prepare_creds(); - if (new < 0) - return -ENOMEM; - - /* newly exec'd tasks don't get a thread keyring */ - key_put(new->thread_keyring); - new->thread_keyring = NULL; - - /* create a new per-thread-group creds for all this set of threads to - * share */ - memcpy(tgcred, new->tgcred, sizeof(struct thread_group_cred)); - - atomic_set(&tgcred->usage, 1); - spin_lock_init(&tgcred->lock); - - /* inherit the session keyring; new process keyring */ - key_get(tgcred->session_keyring); - tgcred->process_keyring = NULL; - - release_tgcred(new); - new->tgcred = tgcred; - - commit_creds(new); - return 0; - -} /* end exec_keys() */ - /*****************************************************************************/ /* * the filesystem user ID changed diff --git a/security/root_plug.c b/security/root_plug.c index c3f68b5b372d..40fb4f15e27b 100644 --- a/security/root_plug.c +++ b/security/root_plug.c @@ -55,9 +55,9 @@ static int rootplug_bprm_check_security (struct linux_binprm *bprm) struct usb_device *dev; root_dbg("file %s, e_uid = %d, e_gid = %d\n", - bprm->filename, bprm->e_uid, bprm->e_gid); + bprm->filename, bprm->cred->euid, bprm->cred->egid); - if (bprm->e_gid == 0) { + if (bprm->cred->egid == 0) { dev = usb_find_device(vendor_id, product_id); if (!dev) { root_dbg("e_gid = 0, and device not found, " @@ -75,15 +75,12 @@ static struct security_operations rootplug_security_ops = { .ptrace_may_access = cap_ptrace_may_access, .ptrace_traceme = cap_ptrace_traceme, .capget = cap_capget, - .capset_check = cap_capset_check, - .capset_set = cap_capset_set, + .capset = cap_capset, .capable = cap_capable, - .bprm_apply_creds = cap_bprm_apply_creds, - .bprm_set_security = cap_bprm_set_security, + .bprm_set_creds = cap_bprm_set_creds, - .task_post_setuid = cap_task_post_setuid, - .task_reparent_to_init = cap_task_reparent_to_init, + .task_fix_setuid = cap_task_fix_setuid, .task_prctl = cap_task_prctl, .bprm_check_security = rootplug_bprm_check_security, diff --git a/security/security.c b/security/security.c index a55d739c6864..dc5babb2d6d8 100644 --- a/security/security.c +++ b/security/security.c @@ -213,34 +213,24 @@ int security_vm_enough_memory_kern(long pages) return security_ops->vm_enough_memory(current->mm, pages); } -int security_bprm_alloc(struct linux_binprm *bprm) +int security_bprm_set_creds(struct linux_binprm *bprm) { - return security_ops->bprm_alloc_security(bprm); + return security_ops->bprm_set_creds(bprm); } -void security_bprm_free(struct linux_binprm *bprm) -{ - security_ops->bprm_free_security(bprm); -} - -int security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) -{ - return security_ops->bprm_apply_creds(bprm, unsafe); -} - -void security_bprm_post_apply_creds(struct linux_binprm *bprm) +int security_bprm_check(struct linux_binprm *bprm) { - security_ops->bprm_post_apply_creds(bprm); + return security_ops->bprm_check_security(bprm); } -int security_bprm_set(struct linux_binprm *bprm) +void security_bprm_committing_creds(struct linux_binprm *bprm) { - return security_ops->bprm_set_security(bprm); + return security_ops->bprm_committing_creds(bprm); } -int security_bprm_check(struct linux_binprm *bprm) +void security_bprm_committed_creds(struct linux_binprm *bprm) { - return security_ops->bprm_check_security(bprm); + return security_ops->bprm_committed_creds(bprm); } int security_bprm_secureexec(struct linux_binprm *bprm) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index c71bba78872f..21a592184633 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2029,59 +2029,45 @@ static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) /* binprm security operations */ -static int selinux_bprm_alloc_security(struct linux_binprm *bprm) +static int selinux_bprm_set_creds(struct linux_binprm *bprm) { - struct bprm_security_struct *bsec; - - bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL); - if (!bsec) - return -ENOMEM; - - bsec->sid = SECINITSID_UNLABELED; - bsec->set = 0; - - bprm->security = bsec; - return 0; -} - -static int selinux_bprm_set_security(struct linux_binprm *bprm) -{ - struct task_security_struct *tsec; - struct inode *inode = bprm->file->f_path.dentry->d_inode; + const struct task_security_struct *old_tsec; + struct task_security_struct *new_tsec; struct inode_security_struct *isec; - struct bprm_security_struct *bsec; - u32 newsid; struct avc_audit_data ad; + struct inode *inode = bprm->file->f_path.dentry->d_inode; int rc; - rc = secondary_ops->bprm_set_security(bprm); + rc = secondary_ops->bprm_set_creds(bprm); if (rc) return rc; - bsec = bprm->security; - - if (bsec->set) + /* SELinux context only depends on initial program or script and not + * the script interpreter */ + if (bprm->cred_prepared) return 0; - tsec = current_security(); + old_tsec = current_security(); + new_tsec = bprm->cred->security; isec = inode->i_security; /* Default to the current task SID. */ - bsec->sid = tsec->sid; + new_tsec->sid = old_tsec->sid; + new_tsec->osid = old_tsec->sid; /* Reset fs, key, and sock SIDs on execve. */ - tsec->create_sid = 0; - tsec->keycreate_sid = 0; - tsec->sockcreate_sid = 0; + new_tsec->create_sid = 0; + new_tsec->keycreate_sid = 0; + new_tsec->sockcreate_sid = 0; - if (tsec->exec_sid) { - newsid = tsec->exec_sid; + if (old_tsec->exec_sid) { + new_tsec->sid = old_tsec->exec_sid; /* Reset exec SID on execve. */ - tsec->exec_sid = 0; + new_tsec->exec_sid = 0; } else { /* Check for a default transition on this program. */ - rc = security_transition_sid(tsec->sid, isec->sid, - SECCLASS_PROCESS, &newsid); + rc = security_transition_sid(old_tsec->sid, isec->sid, + SECCLASS_PROCESS, &new_tsec->sid); if (rc) return rc; } @@ -2090,33 +2076,63 @@ static int selinux_bprm_set_security(struct linux_binprm *bprm) ad.u.fs.path = bprm->file->f_path; if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) - newsid = tsec->sid; + new_tsec->sid = old_tsec->sid; - if (tsec->sid == newsid) { - rc = avc_has_perm(tsec->sid, isec->sid, + if (new_tsec->sid == old_tsec->sid) { + rc = avc_has_perm(old_tsec->sid, isec->sid, SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); if (rc) return rc; } else { /* Check permissions for the transition. */ - rc = avc_has_perm(tsec->sid, newsid, + rc = avc_has_perm(old_tsec->sid, new_tsec->sid, SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); if (rc) return rc; - rc = avc_has_perm(newsid, isec->sid, + rc = avc_has_perm(new_tsec->sid, isec->sid, SECCLASS_FILE, FILE__ENTRYPOINT, &ad); if (rc) return rc; - /* Clear any possibly unsafe personality bits on exec: */ - current->personality &= ~PER_CLEAR_ON_SETID; + /* Check for shared state */ + if (bprm->unsafe & LSM_UNSAFE_SHARE) { + rc = avc_has_perm(old_tsec->sid, new_tsec->sid, + SECCLASS_PROCESS, PROCESS__SHARE, + NULL); + if (rc) + return -EPERM; + } + + /* Make sure that anyone attempting to ptrace over a task that + * changes its SID has the appropriate permit */ + if (bprm->unsafe & + (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { + struct task_struct *tracer; + struct task_security_struct *sec; + u32 ptsid = 0; + + rcu_read_lock(); + tracer = tracehook_tracer_task(current); + if (likely(tracer != NULL)) { + sec = __task_cred(tracer)->security; + ptsid = sec->sid; + } + rcu_read_unlock(); + + if (ptsid != 0) { + rc = avc_has_perm(ptsid, new_tsec->sid, + SECCLASS_PROCESS, + PROCESS__PTRACE, NULL); + if (rc) + return -EPERM; + } + } - /* Set the security field to the new SID. */ - bsec->sid = newsid; + /* Clear any possibly unsafe personality bits on exec: */ + bprm->per_clear |= PER_CLEAR_ON_SETID; } - bsec->set = 1; return 0; } @@ -2125,7 +2141,6 @@ static int selinux_bprm_check_security(struct linux_binprm *bprm) return secondary_ops->bprm_check_security(bprm); } - static int selinux_bprm_secureexec(struct linux_binprm *bprm) { const struct cred *cred = current_cred(); @@ -2141,19 +2156,13 @@ static int selinux_bprm_secureexec(struct linux_binprm *bprm) the noatsecure permission is granted between the two SIDs, i.e. ahp returns 0. */ atsecure = avc_has_perm(osid, sid, - SECCLASS_PROCESS, - PROCESS__NOATSECURE, NULL); + SECCLASS_PROCESS, + PROCESS__NOATSECURE, NULL); } return (atsecure || secondary_ops->bprm_secureexec(bprm)); } -static void selinux_bprm_free_security(struct linux_binprm *bprm) -{ - kfree(bprm->security); - bprm->security = NULL; -} - extern struct vfsmount *selinuxfs_mount; extern struct dentry *selinux_null; @@ -2252,108 +2261,78 @@ static inline void flush_unauthorized_files(const struct cred *cred, spin_unlock(&files->file_lock); } -static int selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) +/* + * Prepare a process for imminent new credential changes due to exec + */ +static void selinux_bprm_committing_creds(struct linux_binprm *bprm) { - struct task_security_struct *tsec; - struct bprm_security_struct *bsec; - struct cred *new; - u32 sid; - int rc; - - rc = secondary_ops->bprm_apply_creds(bprm, unsafe); - if (rc < 0) - return rc; - - new = prepare_creds(); - if (!new) - return -ENOMEM; + struct task_security_struct *new_tsec; + struct rlimit *rlim, *initrlim; + int rc, i; - tsec = new->security; + secondary_ops->bprm_committing_creds(bprm); - bsec = bprm->security; - sid = bsec->sid; - - tsec->osid = tsec->sid; - bsec->unsafe = 0; - if (tsec->sid != sid) { - /* Check for shared state. If not ok, leave SID - unchanged and kill. */ - if (unsafe & LSM_UNSAFE_SHARE) { - rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS, - PROCESS__SHARE, NULL); - if (rc) { - bsec->unsafe = 1; - goto out; - } - } + new_tsec = bprm->cred->security; + if (new_tsec->sid == new_tsec->osid) + return; - /* Check for ptracing, and update the task SID if ok. - Otherwise, leave SID unchanged and kill. */ - if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { - struct task_struct *tracer; - struct task_security_struct *sec; - u32 ptsid = 0; + /* Close files for which the new task SID is not authorized. */ + flush_unauthorized_files(bprm->cred, current->files); - rcu_read_lock(); - tracer = tracehook_tracer_task(current); - if (likely(tracer != NULL)) { - sec = __task_cred(tracer)->security; - ptsid = sec->sid; - } - rcu_read_unlock(); + /* Always clear parent death signal on SID transitions. */ + current->pdeath_signal = 0; - if (ptsid != 0) { - rc = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, - PROCESS__PTRACE, NULL); - if (rc) { - bsec->unsafe = 1; - goto out; - } - } + /* Check whether the new SID can inherit resource limits from the old + * SID. If not, reset all soft limits to the lower of the current + * task's hard limit and the init task's soft limit. + * + * Note that the setting of hard limits (even to lower them) can be + * controlled by the setrlimit check. The inclusion of the init task's + * soft limit into the computation is to avoid resetting soft limits + * higher than the default soft limit for cases where the default is + * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. + */ + rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, + PROCESS__RLIMITINH, NULL); + if (rc) { + for (i = 0; i < RLIM_NLIMITS; i++) { + rlim = current->signal->rlim + i; + initrlim = init_task.signal->rlim + i; + rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); } - tsec->sid = sid; + update_rlimit_cpu(rlim->rlim_cur); } - -out: - commit_creds(new); - return 0; } /* - * called after apply_creds without the task lock held + * Clean up the process immediately after the installation of new credentials + * due to exec */ -static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) +static void selinux_bprm_committed_creds(struct linux_binprm *bprm) { - const struct cred *cred = current_cred(); - struct task_security_struct *tsec; - struct rlimit *rlim, *initrlim; + const struct task_security_struct *tsec = current_security(); struct itimerval itimer; - struct bprm_security_struct *bsec; struct sighand_struct *psig; + u32 osid, sid; int rc, i; unsigned long flags; - tsec = current_security(); - bsec = bprm->security; + secondary_ops->bprm_committed_creds(bprm); - if (bsec->unsafe) { - force_sig_specific(SIGKILL, current); - return; - } - if (tsec->osid == tsec->sid) + osid = tsec->osid; + sid = tsec->sid; + + if (sid == osid) return; - /* Close files for which the new task SID is not authorized. */ - flush_unauthorized_files(cred, current->files); - - /* Check whether the new SID can inherit signal state - from the old SID. If not, clear itimers to avoid - subsequent signal generation and flush and unblock - signals. This must occur _after_ the task SID has - been updated so that any kill done after the flush - will be checked against the new SID. */ - rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS, - PROCESS__SIGINH, NULL); + /* Check whether the new SID can inherit signal state from the old SID. + * If not, clear itimers to avoid subsequent signal generation and + * flush and unblock signals. + * + * This must occur _after_ the task SID has been updated so that any + * kill done after the flush will be checked against the new SID. + */ + rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); if (rc) { memset(&itimer, 0, sizeof itimer); for (i = 0; i < 3; i++) @@ -2366,32 +2345,8 @@ static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) spin_unlock_irq(¤t->sighand->siglock); } - /* Always clear parent death signal on SID transitions. */ - current->pdeath_signal = 0; - - /* Check whether the new SID can inherit resource limits - from the old SID. If not, reset all soft limits to - the lower of the current task's hard limit and the init - task's soft limit. Note that the setting of hard limits - (even to lower them) can be controlled by the setrlimit - check. The inclusion of the init task's soft limit into - the computation is to avoid resetting soft limits higher - than the default soft limit for cases where the default - is lower than the hard limit, e.g. RLIMIT_CORE or - RLIMIT_STACK.*/ - rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS, - PROCESS__RLIMITINH, NULL); - if (rc) { - for (i = 0; i < RLIM_NLIMITS; i++) { - rlim = current->signal->rlim + i; - initrlim = init_task.signal->rlim+i; - rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); - } - update_rlimit_cpu(rlim->rlim_cur); - } - - /* Wake up the parent if it is waiting so that it can - recheck wait permission to the new task SID. */ + /* Wake up the parent if it is waiting so that it can recheck + * wait permission to the new task SID. */ read_lock_irq(&tasklist_lock); psig = current->parent->sighand; spin_lock_irqsave(&psig->siglock, flags); @@ -5556,12 +5511,10 @@ static struct security_operations selinux_ops = { .netlink_send = selinux_netlink_send, .netlink_recv = selinux_netlink_recv, - .bprm_alloc_security = selinux_bprm_alloc_security, - .bprm_free_security = selinux_bprm_free_security, - .bprm_apply_creds = selinux_bprm_apply_creds, - .bprm_post_apply_creds = selinux_bprm_post_apply_creds, - .bprm_set_security = selinux_bprm_set_security, + .bprm_set_creds = selinux_bprm_set_creds, .bprm_check_security = selinux_bprm_check_security, + .bprm_committing_creds = selinux_bprm_committing_creds, + .bprm_committed_creds = selinux_bprm_committed_creds, .bprm_secureexec = selinux_bprm_secureexec, .sb_alloc_security = selinux_sb_alloc_security, diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index f8be8d7fa26d..3cc45168f674 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -77,17 +77,6 @@ struct ipc_security_struct { u32 sid; /* SID of IPC resource */ }; -struct bprm_security_struct { - u32 sid; /* SID for transformed process */ - unsigned char set; - - /* - * unsafe is used to share failure information from bprm_apply_creds() - * to bprm_post_apply_creds(). - */ - char unsafe; -}; - struct netif_security_struct { int ifindex; /* device index */ u32 sid; /* SID for this interface */ diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index e952b397153d..de396742abf4 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2596,8 +2596,7 @@ struct security_operations smack_ops = { .settime = cap_settime, .vm_enough_memory = cap_vm_enough_memory, - .bprm_apply_creds = cap_bprm_apply_creds, - .bprm_set_security = cap_bprm_set_security, + .bprm_set_creds = cap_bprm_set_creds, .bprm_secureexec = cap_bprm_secureexec, .sb_alloc_security = smack_sb_alloc_security, -- cgit v1.2.3 From d76b0d9b2d87cfc95686e148767cbf7d0e22bdc0 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:25 +1100 Subject: CRED: Use creds in file structs Attach creds to file structs and discard f_uid/f_gid. file_operations::open() methods (such as hppfs_open()) should use file->f_cred rather than current_cred(). At the moment file->f_cred will be current_cred() at this point. Signed-off-by: David Howells Reviewed-by: James Morris Signed-off-by: James Morris --- arch/mips/kernel/vpe.c | 4 ++-- drivers/isdn/hysdn/hysdn_procconf.c | 6 ++++-- fs/coda/file.c | 2 +- fs/file_table.c | 7 ++++--- fs/hppfs/hppfs.c | 4 ++-- include/linux/fs.h | 2 +- net/ipv4/netfilter/ipt_LOG.c | 4 ++-- net/ipv6/netfilter/ip6t_LOG.c | 4 ++-- net/netfilter/nfnetlink_log.c | 5 +++-- net/netfilter/xt_owner.c | 16 ++++++++-------- net/sched/cls_flow.c | 4 ++-- 11 files changed, 31 insertions(+), 27 deletions(-) (limited to 'include') diff --git a/arch/mips/kernel/vpe.c b/arch/mips/kernel/vpe.c index 972b2d2b8401..09786e496375 100644 --- a/arch/mips/kernel/vpe.c +++ b/arch/mips/kernel/vpe.c @@ -1085,8 +1085,8 @@ static int vpe_open(struct inode *inode, struct file *filp) v->load_addr = NULL; v->len = 0; - v->uid = filp->f_uid; - v->gid = filp->f_gid; + v->uid = filp->f_cred->fsuid; + v->gid = filp->f_cred->fsgid; #ifdef CONFIG_MIPS_APSP_KSPD /* get kspd to tell us when a syscall_exit happens */ diff --git a/drivers/isdn/hysdn/hysdn_procconf.c b/drivers/isdn/hysdn/hysdn_procconf.c index 484299b031f8..8f9f4912de32 100644 --- a/drivers/isdn/hysdn/hysdn_procconf.c +++ b/drivers/isdn/hysdn/hysdn_procconf.c @@ -246,7 +246,8 @@ hysdn_conf_open(struct inode *ino, struct file *filep) } if (card->debug_flags & (LOG_PROC_OPEN | LOG_PROC_ALL)) hysdn_addlog(card, "config open for uid=%d gid=%d mode=0x%x", - filep->f_uid, filep->f_gid, filep->f_mode); + filep->f_cred->fsuid, filep->f_cred->fsgid, + filep->f_mode); if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) { /* write only access -> write boot file or conf line */ @@ -331,7 +332,8 @@ hysdn_conf_close(struct inode *ino, struct file *filep) } if (card->debug_flags & (LOG_PROC_OPEN | LOG_PROC_ALL)) hysdn_addlog(card, "config close for uid=%d gid=%d mode=0x%x", - filep->f_uid, filep->f_gid, filep->f_mode); + filep->f_cred->fsuid, filep->f_cred->fsgid, + filep->f_mode); if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) { /* write only access -> write boot file or conf line */ diff --git a/fs/coda/file.c b/fs/coda/file.c index 29137ff3ca67..5a8769985494 100644 --- a/fs/coda/file.c +++ b/fs/coda/file.c @@ -174,7 +174,7 @@ int coda_release(struct inode *coda_inode, struct file *coda_file) BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode), - coda_flags, coda_file->f_uid); + coda_flags, coda_file->f_cred->fsuid); host_inode = cfi->cfi_container->f_path.dentry->d_inode; cii = ITOC(coda_inode); diff --git a/fs/file_table.c b/fs/file_table.c index bc4563fe791d..0fbcacc3ea75 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -36,7 +36,9 @@ static struct percpu_counter nr_files __cacheline_aligned_in_smp; static inline void file_free_rcu(struct rcu_head *head) { - struct file *f = container_of(head, struct file, f_u.fu_rcuhead); + struct file *f = container_of(head, struct file, f_u.fu_rcuhead); + + put_cred(f->f_cred); kmem_cache_free(filp_cachep, f); } @@ -121,8 +123,7 @@ struct file *get_empty_filp(void) INIT_LIST_HEAD(&f->f_u.fu_list); atomic_long_set(&f->f_count, 1); rwlock_init(&f->f_owner.lock); - f->f_uid = cred->fsuid; - f->f_gid = cred->fsgid; + f->f_cred = get_cred(cred); eventpoll_init_file(f); /* f->f_version: 0 */ return f; diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c index 795e2c130ad7..b278f7f52024 100644 --- a/fs/hppfs/hppfs.c +++ b/fs/hppfs/hppfs.c @@ -426,7 +426,7 @@ static int file_mode(int fmode) static int hppfs_open(struct inode *inode, struct file *file) { - const struct cred *cred = current_cred(); + const struct cred *cred = file->f_cred; struct hppfs_private *data; struct vfsmount *proc_mnt; struct dentry *proc_dentry; @@ -490,7 +490,7 @@ static int hppfs_open(struct inode *inode, struct file *file) static int hppfs_dir_open(struct inode *inode, struct file *file) { - const struct cred *cred = current_cred(); + const struct cred *cred = file->f_cred; struct hppfs_private *data; struct vfsmount *proc_mnt; struct dentry *proc_dentry; diff --git a/include/linux/fs.h b/include/linux/fs.h index 3bfec1327b8d..c0fb6d81d89b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -827,7 +827,7 @@ struct file { fmode_t f_mode; loff_t f_pos; struct fown_struct f_owner; - unsigned int f_uid, f_gid; + const struct cred *f_cred; struct file_ra_state f_ra; u64 f_version; diff --git a/net/ipv4/netfilter/ipt_LOG.c b/net/ipv4/netfilter/ipt_LOG.c index fc6ce04a3e35..7b5dbe118c09 100644 --- a/net/ipv4/netfilter/ipt_LOG.c +++ b/net/ipv4/netfilter/ipt_LOG.c @@ -340,8 +340,8 @@ static void dump_packet(const struct nf_loginfo *info, read_lock_bh(&skb->sk->sk_callback_lock); if (skb->sk->sk_socket && skb->sk->sk_socket->file) printk("UID=%u GID=%u ", - skb->sk->sk_socket->file->f_uid, - skb->sk->sk_socket->file->f_gid); + skb->sk->sk_socket->file->f_cred->fsuid, + skb->sk->sk_socket->file->f_cred->fsgid); read_unlock_bh(&skb->sk->sk_callback_lock); } diff --git a/net/ipv6/netfilter/ip6t_LOG.c b/net/ipv6/netfilter/ip6t_LOG.c index caa441d09567..871d157cec4e 100644 --- a/net/ipv6/netfilter/ip6t_LOG.c +++ b/net/ipv6/netfilter/ip6t_LOG.c @@ -364,8 +364,8 @@ static void dump_packet(const struct nf_loginfo *info, read_lock_bh(&skb->sk->sk_callback_lock); if (skb->sk->sk_socket && skb->sk->sk_socket->file) printk("UID=%u GID=%u ", - skb->sk->sk_socket->file->f_uid, - skb->sk->sk_socket->file->f_gid); + skb->sk->sk_socket->file->f_cred->fsuid, + skb->sk->sk_socket->file->f_cred->fsgid); read_unlock_bh(&skb->sk->sk_callback_lock); } diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index 41e0105d3828..38f9efd90e8d 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -474,8 +474,9 @@ __build_packet_message(struct nfulnl_instance *inst, if (skb->sk) { read_lock_bh(&skb->sk->sk_callback_lock); if (skb->sk->sk_socket && skb->sk->sk_socket->file) { - __be32 uid = htonl(skb->sk->sk_socket->file->f_uid); - __be32 gid = htonl(skb->sk->sk_socket->file->f_gid); + struct file *file = skb->sk->sk_socket->file; + __be32 uid = htonl(file->f_cred->fsuid); + __be32 gid = htonl(file->f_cred->fsgid); /* need to unlock here since NLA_PUT may goto */ read_unlock_bh(&skb->sk->sk_callback_lock); NLA_PUT_BE32(inst->skb, NFULA_UID, uid); diff --git a/net/netfilter/xt_owner.c b/net/netfilter/xt_owner.c index f19ebd9b78f5..22b2a5e881ea 100644 --- a/net/netfilter/xt_owner.c +++ b/net/netfilter/xt_owner.c @@ -34,12 +34,12 @@ owner_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par) return false; if (info->match & IPT_OWNER_UID) - if ((filp->f_uid != info->uid) ^ + if ((filp->f_cred->fsuid != info->uid) ^ !!(info->invert & IPT_OWNER_UID)) return false; if (info->match & IPT_OWNER_GID) - if ((filp->f_gid != info->gid) ^ + if ((filp->f_cred->fsgid != info->gid) ^ !!(info->invert & IPT_OWNER_GID)) return false; @@ -60,12 +60,12 @@ owner_mt6_v0(const struct sk_buff *skb, const struct xt_match_param *par) return false; if (info->match & IP6T_OWNER_UID) - if ((filp->f_uid != info->uid) ^ + if ((filp->f_cred->fsuid != info->uid) ^ !!(info->invert & IP6T_OWNER_UID)) return false; if (info->match & IP6T_OWNER_GID) - if ((filp->f_gid != info->gid) ^ + if ((filp->f_cred->fsgid != info->gid) ^ !!(info->invert & IP6T_OWNER_GID)) return false; @@ -93,14 +93,14 @@ owner_mt(const struct sk_buff *skb, const struct xt_match_param *par) (XT_OWNER_UID | XT_OWNER_GID)) == 0; if (info->match & XT_OWNER_UID) - if ((filp->f_uid >= info->uid_min && - filp->f_uid <= info->uid_max) ^ + if ((filp->f_cred->fsuid >= info->uid_min && + filp->f_cred->fsuid <= info->uid_max) ^ !(info->invert & XT_OWNER_UID)) return false; if (info->match & XT_OWNER_GID) - if ((filp->f_gid >= info->gid_min && - filp->f_gid <= info->gid_max) ^ + if ((filp->f_cred->fsgid >= info->gid_min && + filp->f_cred->fsgid <= info->gid_max) ^ !(info->invert & XT_OWNER_GID)) return false; diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c index 0ebaff637e31..0ef4e3065bcd 100644 --- a/net/sched/cls_flow.c +++ b/net/sched/cls_flow.c @@ -260,14 +260,14 @@ static u32 flow_get_rtclassid(const struct sk_buff *skb) static u32 flow_get_skuid(const struct sk_buff *skb) { if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) - return skb->sk->sk_socket->file->f_uid; + return skb->sk->sk_socket->file->f_cred->fsuid; return 0; } static u32 flow_get_skgid(const struct sk_buff *skb) { if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) - return skb->sk->sk_socket->file->f_gid; + return skb->sk->sk_socket->file->f_cred->fsgid; return 0; } -- cgit v1.2.3 From 98870ab0a5a3f1822aee681d2997017e1c87d026 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:26 +1100 Subject: CRED: Documentation Document credentials and the new credentials API. Signed-off-by: David Howells Signed-off-by: James Morris --- Documentation/credentials.txt | 582 ++++++++++++++++++++++++++++++++++++++++++ include/linux/cred.h | 12 +- kernel/cred.c | 2 +- 3 files changed, 594 insertions(+), 2 deletions(-) create mode 100644 Documentation/credentials.txt (limited to 'include') diff --git a/Documentation/credentials.txt b/Documentation/credentials.txt new file mode 100644 index 000000000000..df03169782ea --- /dev/null +++ b/Documentation/credentials.txt @@ -0,0 +1,582 @@ + ==================== + CREDENTIALS IN LINUX + ==================== + +By: David Howells + +Contents: + + (*) Overview. + + (*) Types of credentials. + + (*) File markings. + + (*) Task credentials. + + - Immutable credentials. + - Accessing task credentials. + - Accessing another task's credentials. + - Altering credentials. + - Managing credentials. + + (*) Open file credentials. + + (*) Overriding the VFS's use of credentials. + + +======== +OVERVIEW +======== + +There are several parts to the security check performed by Linux when one +object acts upon another: + + (1) Objects. + + Objects are things in the system that may be acted upon directly by + userspace programs. Linux has a variety of actionable objects, including: + + - Tasks + - Files/inodes + - Sockets + - Message queues + - Shared memory segments + - Semaphores + - Keys + + As a part of the description of all these objects there is a set of + credentials. What's in the set depends on the type of object. + + (2) Object ownership. + + Amongst the credentials of most objects, there will be a subset that + indicates the ownership of that object. This is used for resource + accounting and limitation (disk quotas and task rlimits for example). + + In a standard UNIX filesystem, for instance, this will be defined by the + UID marked on the inode. + + (3) The objective context. + + Also amongst the credentials of those objects, there will be a subset that + indicates the 'objective context' of that object. This may or may not be + the same set as in (2) - in standard UNIX files, for instance, this is the + defined by the UID and the GID marked on the inode. + + The objective context is used as part of the security calculation that is + carried out when an object is acted upon. + + (4) Subjects. + + A subject is an object that is acting upon another object. + + Most of the objects in the system are inactive: they don't act on other + objects within the system. Processes/tasks are the obvious exception: + they do stuff; they access and manipulate things. + + Objects other than tasks may under some circumstances also be subjects. + For instance an open file may send SIGIO to a task using the UID and EUID + given to it by a task that called fcntl(F_SETOWN) upon it. In this case, + the file struct will have a subjective context too. + + (5) The subjective context. + + A subject has an additional interpretation of its credentials. A subset + of its credentials forms the 'subjective context'. The subjective context + is used as part of the security calculation that is carried out when a + subject acts. + + A Linux task, for example, has the FSUID, FSGID and the supplementary + group list for when it is acting upon a file - which are quite separate + from the real UID and GID that normally form the objective context of the + task. + + (6) Actions. + + Linux has a number of actions available that a subject may perform upon an + object. The set of actions available depends on the nature of the subject + and the object. + + Actions include reading, writing, creating and deleting files; forking or + signalling and tracing tasks. + + (7) Rules, access control lists and security calculations. + + When a subject acts upon an object, a security calculation is made. This + involves taking the subjective context, the objective context and the + action, and searching one or more sets of rules to see whether the subject + is granted or denied permission to act in the desired manner on the + object, given those contexts. + + There are two main sources of rules: + + (a) Discretionary access control (DAC): + + Sometimes the object will include sets of rules as part of its + description. This is an 'Access Control List' or 'ACL'. A Linux + file may supply more than one ACL. + + A traditional UNIX file, for example, includes a permissions mask that + is an abbreviated ACL with three fixed classes of subject ('user', + 'group' and 'other'), each of which may be granted certain privileges + ('read', 'write' and 'execute' - whatever those map to for the object + in question). UNIX file permissions do not allow the arbitrary + specification of subjects, however, and so are of limited use. + + A Linux file might also sport a POSIX ACL. This is a list of rules + that grants various permissions to arbitrary subjects. + + (b) Mandatory access control (MAC): + + The system as a whole may have one or more sets of rules that get + applied to all subjects and objects, regardless of their source. + SELinux and Smack are examples of this. + + In the case of SELinux and Smack, each object is given a label as part + of its credentials. When an action is requested, they take the + subject label, the object label and the action and look for a rule + that says that this action is either granted or denied. + + +==================== +TYPES OF CREDENTIALS +==================== + +The Linux kernel supports the following types of credentials: + + (1) Traditional UNIX credentials. + + Real User ID + Real Group ID + + The UID and GID are carried by most, if not all, Linux objects, even if in + some cases it has to be invented (FAT or CIFS files for example, which are + derived from Windows). These (mostly) define the objective context of + that object, with tasks being slightly different in some cases. + + Effective, Saved and FS User ID + Effective, Saved and FS Group ID + Supplementary groups + + These are additional credentials used by tasks only. Usually, an + EUID/EGID/GROUPS will be used as the subjective context, and real UID/GID + will be used as the objective. For tasks, it should be noted that this is + not always true. + + (2) Capabilities. + + Set of permitted capabilities + Set of inheritable capabilities + Set of effective capabilities + Capability bounding set + + These are only carried by tasks. They indicate superior capabilities + granted piecemeal to a task that an ordinary task wouldn't otherwise have. + These are manipulated implicitly by changes to the traditional UNIX + credentials, but can also be manipulated directly by the capset() system + call. + + The permitted capabilities are those caps that the process might grant + itself to its effective or permitted sets through capset(). This + inheritable set might also be so constrained. + + The effective capabilities are the ones that a task is actually allowed to + make use of itself. + + The inheritable capabilities are the ones that may get passed across + execve(). + + The bounding set limits the capabilities that may be inherited across + execve(), especially when a binary is executed that will execute as UID 0. + + (3) Secure management flags (securebits). + + These are only carried by tasks. These govern the way the above + credentials are manipulated and inherited over certain operations such as + execve(). They aren't used directly as objective or subjective + credentials. + + (4) Keys and keyrings. + + These are only carried by tasks. They carry and cache security tokens + that don't fit into the other standard UNIX credentials. They are for + making such things as network filesystem keys available to the file + accesses performed by processes, without the necessity of ordinary + programs having to know about security details involved. + + Keyrings are a special type of key. They carry sets of other keys and can + be searched for the desired key. Each process may subscribe to a number + of keyrings: + + Per-thread keying + Per-process keyring + Per-session keyring + + When a process accesses a key, if not already present, it will normally be + cached on one of these keyrings for future accesses to find. + + For more information on using keys, see Documentation/keys.txt. + + (5) LSM + + The Linux Security Module allows extra controls to be placed over the + operations that a task may do. Currently Linux supports two main + alternate LSM options: SELinux and Smack. + + Both work by labelling the objects in a system and then applying sets of + rules (policies) that say what operations a task with one label may do to + an object with another label. + + (6) AF_KEY + + This is a socket-based approach to credential management for networking + stacks [RFC 2367]. It isn't discussed by this document as it doesn't + interact directly with task and file credentials; rather it keeps system + level credentials. + + +When a file is opened, part of the opening task's subjective context is +recorded in the file struct created. This allows operations using that file +struct to use those credentials instead of the subjective context of the task +that issued the operation. An example of this would be a file opened on a +network filesystem where the credentials of the opened file should be presented +to the server, regardless of who is actually doing a read or a write upon it. + + +============= +FILE MARKINGS +============= + +Files on disk or obtained over the network may have annotations that form the +objective security context of that file. Depending on the type of filesystem, +this may include one or more of the following: + + (*) UNIX UID, GID, mode; + + (*) Windows user ID; + + (*) Access control list; + + (*) LSM security label; + + (*) UNIX exec privilege escalation bits (SUID/SGID); + + (*) File capabilities exec privilege escalation bits. + +These are compared to the task's subjective security context, and certain +operations allowed or disallowed as a result. In the case of execve(), the +privilege escalation bits come into play, and may allow the resulting process +extra privileges, based on the annotations on the executable file. + + +================ +TASK CREDENTIALS +================ + +In Linux, all of a task's credentials are held in (uid, gid) or through +(groups, keys, LSM security) a refcounted structure of type 'struct cred'. +Each task points to its credentials by a pointer called 'cred' in its +task_struct. + +Once a set of credentials has been prepared and committed, it may not be +changed, barring the following exceptions: + + (1) its reference count may be changed; + + (2) the reference count on the group_info struct it points to may be changed; + + (3) the reference count on the security data it points to may be changed; + + (4) the reference count on any keyrings it points to may be changed; + + (5) any keyrings it points to may be revoked, expired or have their security + attributes changed; and + + (6) the contents of any keyrings to which it points may be changed (the whole + point of keyrings being a shared set of credentials, modifiable by anyone + with appropriate access). + +To alter anything in the cred struct, the copy-and-replace principle must be +adhered to. First take a copy, then alter the copy and then use RCU to change +the task pointer to make it point to the new copy. There are wrappers to aid +with this (see below). + +A task may only alter its _own_ credentials; it is no longer permitted for a +task to alter another's credentials. This means the capset() system call is no +longer permitted to take any PID other than the one of the current process. +Also keyctl_instantiate() and keyctl_negate() functions no longer permit +attachment to process-specific keyrings in the requesting process as the +instantiating process may need to create them. + + +IMMUTABLE CREDENTIALS +--------------------- + +Once a set of credentials has been made public (by calling commit_creds() for +example), it must be considered immutable, barring two exceptions: + + (1) The reference count may be altered. + + (2) Whilst the keyring subscriptions of a set of credentials may not be + changed, the keyrings subscribed to may have their contents altered. + +To catch accidental credential alteration at compile time, struct task_struct +has _const_ pointers to its credential sets, as does struct file. Furthermore, +certain functions such as get_cred() and put_cred() operate on const pointers, +thus rendering casts unnecessary, but require to temporarily ditch the const +qualification to be able to alter the reference count. + + +ACCESSING TASK CREDENTIALS +-------------------------- + +A task being able to alter only its own credentials permits the current process +to read or replace its own credentials without the need for any form of locking +- which simplifies things greatly. It can just call: + + const struct cred *current_cred() + +to get a pointer to its credentials structure, and it doesn't have to release +it afterwards. + +There are convenience wrappers for retrieving specific aspects of a task's +credentials (the value is simply returned in each case): + + uid_t current_uid(void) Current's real UID + gid_t current_gid(void) Current's real GID + uid_t current_euid(void) Current's effective UID + gid_t current_egid(void) Current's effective GID + uid_t current_fsuid(void) Current's file access UID + gid_t current_fsgid(void) Current's file access GID + kernel_cap_t current_cap(void) Current's effective capabilities + void *current_security(void) Current's LSM security pointer + struct user_struct *current_user(void) Current's user account + +There are also convenience wrappers for retrieving specific associated pairs of +a task's credentials: + + void current_uid_gid(uid_t *, gid_t *); + void current_euid_egid(uid_t *, gid_t *); + void current_fsuid_fsgid(uid_t *, gid_t *); + +which return these pairs of values through their arguments after retrieving +them from the current task's credentials. + + +In addition, there is a function for obtaining a reference on the current +process's current set of credentials: + + const struct cred *get_current_cred(void); + +and functions for getting references to one of the credentials that don't +actually live in struct cred: + + struct user_struct *get_current_user(void); + struct group_info *get_current_groups(void); + +which get references to the current process's user accounting structure and +supplementary groups list respectively. + +Once a reference has been obtained, it must be released with put_cred(), +free_uid() or put_group_info() as appropriate. + + +ACCESSING ANOTHER TASK'S CREDENTIALS +------------------------------------ + +Whilst a task may access its own credentials without the need for locking, the +same is not true of a task wanting to access another task's credentials. It +must use the RCU read lock and rcu_dereference(). + +The rcu_dereference() is wrapped by: + + const struct cred *__task_cred(struct task_struct *task); + +This should be used inside the RCU read lock, as in the following example: + + void foo(struct task_struct *t, struct foo_data *f) + { + const struct cred *tcred; + ... + rcu_read_lock(); + tcred = __task_cred(t); + f->uid = tcred->uid; + f->gid = tcred->gid; + f->groups = get_group_info(tcred->groups); + rcu_read_unlock(); + ... + } + +A function need not get RCU read lock to use __task_cred() if it is holding a +spinlock at the time as this implicitly holds the RCU read lock. + +Should it be necessary to hold another task's credentials for a long period of +time, and possibly to sleep whilst doing so, then the caller should get a +reference on them using: + + const struct cred *get_task_cred(struct task_struct *task); + +This does all the RCU magic inside of it. The caller must call put_cred() on +the credentials so obtained when they're finished with. + +There are a couple of convenience functions to access bits of another task's +credentials, hiding the RCU magic from the caller: + + uid_t task_uid(task) Task's real UID + uid_t task_euid(task) Task's effective UID + +If the caller is holding a spinlock or the RCU read lock at the time anyway, +then: + + __task_cred(task)->uid + __task_cred(task)->euid + +should be used instead. Similarly, if multiple aspects of a task's credentials +need to be accessed, RCU read lock or a spinlock should be used, __task_cred() +called, the result stored in a temporary pointer and then the credential +aspects called from that before dropping the lock. This prevents the +potentially expensive RCU magic from being invoked multiple times. + +Should some other single aspect of another task's credentials need to be +accessed, then this can be used: + + task_cred_xxx(task, member) + +where 'member' is a non-pointer member of the cred struct. For instance: + + uid_t task_cred_xxx(task, suid); + +will retrieve 'struct cred::suid' from the task, doing the appropriate RCU +magic. This may not be used for pointer members as what they point to may +disappear the moment the RCU read lock is dropped. + + +ALTERING CREDENTIALS +-------------------- + +As previously mentioned, a task may only alter its own credentials, and may not +alter those of another task. This means that it doesn't need to use any +locking to alter its own credentials. + +To alter the current process's credentials, a function should first prepare a +new set of credentials by calling: + + struct cred *prepare_creds(void); + +this locks current->cred_replace_mutex and then allocates and constructs a +duplicate of the current process's credentials, returning with the mutex still +held if successful. It returns NULL if not successful (out of memory). + +The mutex prevents ptrace() from altering the ptrace state of a process whilst +security checks on credentials construction and changing is taking place as +the ptrace state may alter the outcome, particularly in the case of execve(). + +The new credentials set should be altered appropriately, and any security +checks and hooks done. Both the current and the proposed sets of credentials +are available for this purpose as current_cred() will return the current set +still at this point. + + +When the credential set is ready, it should be committed to the current process +by calling: + + int commit_creds(struct cred *new); + +This will alter various aspects of the credentials and the process, giving the +LSM a chance to do likewise, then it will use rcu_assign_pointer() to actually +commit the new credentials to current->cred, it will release +current->cred_replace_mutex to allow ptrace() to take place, and it will notify +the scheduler and others of the changes. + +This function is guaranteed to return 0, so that it can be tail-called at the +end of such functions as sys_setresuid(). + +Note that this function consumes the caller's reference to the new credentials. +The caller should _not_ call put_cred() on the new credentials afterwards. + +Furthermore, once this function has been called on a new set of credentials, +those credentials may _not_ be changed further. + + +Should the security checks fail or some other error occur after prepare_creds() +has been called, then the following function should be invoked: + + void abort_creds(struct cred *new); + +This releases the lock on current->cred_replace_mutex that prepare_creds() got +and then releases the new credentials. + + +A typical credentials alteration function would look something like this: + + int alter_suid(uid_t suid) + { + struct cred *new; + int ret; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + new->suid = suid; + ret = security_alter_suid(new); + if (ret < 0) { + abort_creds(new); + return ret; + } + + return commit_creds(new); + } + + +MANAGING CREDENTIALS +-------------------- + +There are some functions to help manage credentials: + + (*) void put_cred(const struct cred *cred); + + This releases a reference to the given set of credentials. If the + reference count reaches zero, the credentials will be scheduled for + destruction by the RCU system. + + (*) const struct cred *get_cred(const struct cred *cred); + + This gets a reference on a live set of credentials, returning a pointer to + that set of credentials. + + (*) struct cred *get_new_cred(struct cred *cred); + + This gets a reference on a set of credentials that is under construction + and is thus still mutable, returning a pointer to that set of credentials. + + +===================== +OPEN FILE CREDENTIALS +===================== + +When a new file is opened, a reference is obtained on the opening task's +credentials and this is attached to the file struct as 'f_cred' in place of +'f_uid' and 'f_gid'. Code that used to access file->f_uid and file->f_gid +should now access file->f_cred->fsuid and file->f_cred->fsgid. + +It is safe to access f_cred without the use of RCU or locking because the +pointer will not change over the lifetime of the file struct, and nor will the +contents of the cred struct pointed to, barring the exceptions listed above +(see the Task Credentials section). + + +======================================= +OVERRIDING THE VFS'S USE OF CREDENTIALS +======================================= + +Under some circumstances it is desirable to override the credentials used by +the VFS, and that can be done by calling into such as vfs_mkdir() with a +different set of credentials. This is done in the following places: + + (*) sys_faccessat(). + + (*) do_coredump(). + + (*) nfs4recover.c. diff --git a/include/linux/cred.h b/include/linux/cred.h index 8edb4d1d5427..794aab5c66e5 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -1,4 +1,4 @@ -/* Credentials management +/* Credentials management - see Documentation/credentials.txt * * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) @@ -169,6 +169,12 @@ static inline struct cred *get_new_cred(struct cred *cred) * * Get a reference on the specified set of credentials. The caller must * release the reference. + * + * This is used to deal with a committed set of credentials. Although the + * pointer is const, this will temporarily discard the const and increment the + * usage count. The purpose of this is to attempt to catch at compile time the + * accidental alteration of a set of credentials that should be considered + * immutable. */ static inline const struct cred *get_cred(const struct cred *cred) { @@ -181,6 +187,10 @@ static inline const struct cred *get_cred(const struct cred *cred) * * Release a reference to a set of credentials, deleting them when the last ref * is released. + * + * This takes a const pointer to a set of credentials because the credentials + * on task_struct are attached by const pointers to prevent accidental + * alteration of otherwise immutable credential sets. */ static inline void put_cred(const struct cred *_cred) { diff --git a/kernel/cred.c b/kernel/cred.c index e6fcdd67b2ec..b8bd2f99d8ce 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -1,4 +1,4 @@ -/* Task credentials management +/* Task credentials management - see Documentation/credentials.txt * * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) -- cgit v1.2.3 From 3b11a1decef07c19443d24ae926982bc8ec9f4c0 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:26 +1100 Subject: CRED: Differentiate objective and effective subjective credentials on a task Differentiate the objective and real subjective credentials from the effective subjective credentials on a task by introducing a second credentials pointer into the task_struct. task_struct::real_cred then refers to the objective and apparent real subjective credentials of a task, as perceived by the other tasks in the system. task_struct::cred then refers to the effective subjective credentials of a task, as used by that task when it's actually running. These are not visible to the other tasks in the system. __task_cred(task) then refers to the objective/real credentials of the task in question. current_cred() refers to the effective subjective credentials of the current task. prepare_creds() uses the objective creds as a base and commit_creds() changes both pointers in the task_struct (indeed commit_creds() requires them to be the same). override_creds() and revert_creds() change the subjective creds pointer only, and the former returns the old subjective creds. These are used by NFSD, faccessat() and do_coredump(), and will by used by CacheFiles. In SELinux, current_has_perm() is provided as an alternative to task_has_perm(). This uses the effective subjective context of current, whereas task_has_perm() uses the objective/real context of the subject. Signed-off-by: David Howells Signed-off-by: James Morris --- fs/nfsd/auth.c | 5 +++- include/linux/cred.h | 29 +++++++++++---------- include/linux/init_task.h | 1 + include/linux/sched.h | 5 +++- kernel/cred.c | 38 ++++++++++++++++++--------- kernel/fork.c | 6 +++-- security/selinux/hooks.c | 65 ++++++++++++++++++++++++++++++----------------- 7 files changed, 95 insertions(+), 54 deletions(-) (limited to 'include') diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c index 836ffa1047d9..0184fe9b514c 100644 --- a/fs/nfsd/auth.c +++ b/fs/nfsd/auth.c @@ -34,6 +34,8 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp) int flags = nfsexp_flags(rqstp, exp); int ret; + /* discard any old override before preparing the new set */ + revert_creds(get_cred(current->real_cred)); new = prepare_creds(); if (!new) return -ENOMEM; @@ -82,7 +84,8 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp) else new->cap_effective = cap_raise_nfsd_set(new->cap_effective, new->cap_permitted); - return commit_creds(new); + put_cred(override_creds(new)); + return 0; oom: ret = -ENOMEM; diff --git a/include/linux/cred.h b/include/linux/cred.h index 794aab5c66e5..55a9c995d694 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -146,8 +146,8 @@ extern struct cred *prepare_exec_creds(void); extern struct cred *prepare_usermodehelper_creds(void); extern int commit_creds(struct cred *); extern void abort_creds(struct cred *); -extern const struct cred *override_creds(const struct cred *) __deprecated; -extern void revert_creds(const struct cred *) __deprecated; +extern const struct cred *override_creds(const struct cred *); +extern void revert_creds(const struct cred *); extern void __init cred_init(void); /** @@ -202,32 +202,32 @@ static inline void put_cred(const struct cred *_cred) } /** - * current_cred - Access the current task's credentials + * current_cred - Access the current task's subjective credentials * - * Access the credentials of the current task. + * Access the subjective credentials of the current task. */ #define current_cred() \ (current->cred) /** - * __task_cred - Access another task's credentials + * __task_cred - Access a task's objective credentials * @task: The task to query * - * Access the credentials of another task. The caller must hold the - * RCU readlock. + * Access the objective credentials of a task. The caller must hold the RCU + * readlock. * * The caller must make sure task doesn't go away, either by holding a ref on * task or by holding tasklist_lock to prevent it from being unlinked. */ #define __task_cred(task) \ - ((const struct cred *)(rcu_dereference((task)->cred))) + ((const struct cred *)(rcu_dereference((task)->real_cred))) /** - * get_task_cred - Get another task's credentials + * get_task_cred - Get another task's objective credentials * @task: The task to query * - * Get the credentials of a task, pinning them so that they can't go away. - * Accessing a task's credentials directly is not permitted. + * Get the objective credentials of a task, pinning them so that they can't go + * away. Accessing a task's credentials directly is not permitted. * * The caller must make sure task doesn't go away, either by holding a ref on * task or by holding tasklist_lock to prevent it from being unlinked. @@ -243,10 +243,11 @@ static inline void put_cred(const struct cred *_cred) }) /** - * get_current_cred - Get the current task's credentials + * get_current_cred - Get the current task's subjective credentials * - * Get the credentials of the current task, pinning them so that they can't go - * away. Accessing the current task's credentials directly is not permitted. + * Get the subjective credentials of the current task, pinning them so that + * they can't go away. Accessing the current task's credentials directly is + * not permitted. */ #define get_current_cred() \ (get_cred(current_cred())) diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 08c3b24ad9a8..2597858035cd 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -149,6 +149,7 @@ extern struct cred init_cred; .children = LIST_HEAD_INIT(tsk.children), \ .sibling = LIST_HEAD_INIT(tsk.sibling), \ .group_leader = &tsk, \ + .real_cred = &init_cred, \ .cred = &init_cred, \ .cred_exec_mutex = \ __MUTEX_INITIALIZER(tsk.cred_exec_mutex), \ diff --git a/include/linux/sched.h b/include/linux/sched.h index 121d655e460d..3443123b0709 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1145,7 +1145,10 @@ struct task_struct { struct list_head cpu_timers[3]; /* process credentials */ - const struct cred *cred; /* actual/objective task credentials (COW) */ + const struct cred *real_cred; /* objective and real subjective task + * credentials (COW) */ + const struct cred *cred; /* effective (overridable) subjective task + * credentials (COW) */ struct mutex cred_exec_mutex; /* execve vs ptrace cred calculation mutex */ char comm[TASK_COMM_LEN]; /* executable name excluding path diff --git a/kernel/cred.c b/kernel/cred.c index b8bd2f99d8ce..f3ca10660617 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -35,7 +35,7 @@ static struct thread_group_cred init_tgcred = { * The initial credentials for the initial task */ struct cred init_cred = { - .usage = ATOMIC_INIT(3), + .usage = ATOMIC_INIT(4), .securebits = SECUREBITS_DEFAULT, .cap_inheritable = CAP_INIT_INH_SET, .cap_permitted = CAP_FULL_SET, @@ -120,6 +120,8 @@ EXPORT_SYMBOL(__put_cred); * prepare a new copy, which the caller then modifies and then commits by * calling commit_creds(). * + * Preparation involves making a copy of the objective creds for modification. + * * Returns a pointer to the new creds-to-be if successful, NULL otherwise. * * Call commit_creds() or abort_creds() to clean up. @@ -130,7 +132,7 @@ struct cred *prepare_creds(void) const struct cred *old; struct cred *new; - BUG_ON(atomic_read(&task->cred->usage) < 1); + BUG_ON(atomic_read(&task->real_cred->usage) < 1); new = kmem_cache_alloc(cred_jar, GFP_KERNEL); if (!new) @@ -262,6 +264,9 @@ error: * * We share if we can, but under some circumstances we have to generate a new * set. + * + * The new process gets the current process's subjective credentials as its + * objective and subjective credentials */ int copy_creds(struct task_struct *p, unsigned long clone_flags) { @@ -278,6 +283,7 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) #endif clone_flags & CLONE_THREAD ) { + p->real_cred = get_cred(p->cred); get_cred(p->cred); atomic_inc(&p->cred->user->processes); return 0; @@ -317,7 +323,7 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) #endif atomic_inc(&new->user->processes); - p->cred = new; + p->cred = p->real_cred = get_cred(new); return 0; } @@ -326,7 +332,9 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) * @new: The credentials to be assigned * * Install a new set of credentials to the current task, using RCU to replace - * the old set. + * the old set. Both the objective and the subjective credentials pointers are + * updated. This function may not be called if the subjective credentials are + * in an overridden state. * * This function eats the caller's reference to the new credentials. * @@ -338,12 +346,15 @@ int commit_creds(struct cred *new) struct task_struct *task = current; const struct cred *old; + BUG_ON(task->cred != task->real_cred); + BUG_ON(atomic_read(&task->real_cred->usage) < 2); BUG_ON(atomic_read(&new->usage) < 1); - BUG_ON(atomic_read(&task->cred->usage) < 1); - old = task->cred; + old = task->real_cred; security_commit_creds(new, old); + get_cred(new); /* we will require a ref for the subj creds too */ + /* dumpability changes */ if (old->euid != new->euid || old->egid != new->egid || @@ -369,6 +380,7 @@ int commit_creds(struct cred *new) */ if (new->user != old->user) atomic_inc(&new->user->processes); + rcu_assign_pointer(task->real_cred, new); rcu_assign_pointer(task->cred, new); if (new->user != old->user) atomic_dec(&old->user->processes); @@ -388,6 +400,8 @@ int commit_creds(struct cred *new) new->fsgid != old->fsgid) proc_id_connector(task, PROC_EVENT_GID); + /* release the old obj and subj refs both */ + put_cred(old); put_cred(old); return 0; } @@ -408,11 +422,11 @@ void abort_creds(struct cred *new) EXPORT_SYMBOL(abort_creds); /** - * override_creds - Temporarily override the current process's credentials + * override_creds - Override the current process's subjective credentials * @new: The credentials to be assigned * - * Install a set of temporary override credentials on the current process, - * returning the old set for later reversion. + * Install a set of temporary override subjective credentials on the current + * process, returning the old set for later reversion. */ const struct cred *override_creds(const struct cred *new) { @@ -424,11 +438,11 @@ const struct cred *override_creds(const struct cred *new) EXPORT_SYMBOL(override_creds); /** - * revert_creds - Revert a temporary credentials override + * revert_creds - Revert a temporary subjective credentials override * @old: The credentials to be restored * - * Revert a temporary set of override credentials to an old set, discarding the - * override set. + * Revert a temporary set of override subjective credentials to an old set, + * discarding the override set. */ void revert_creds(const struct cred *old) { diff --git a/kernel/fork.c b/kernel/fork.c index 82a7948a664e..af0d0f04585c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -146,6 +146,7 @@ void __put_task_struct(struct task_struct *tsk) WARN_ON(atomic_read(&tsk->usage)); WARN_ON(tsk == current); + put_cred(tsk->real_cred); put_cred(tsk->cred); delayacct_tsk_free(tsk); @@ -961,10 +962,10 @@ static struct task_struct *copy_process(unsigned long clone_flags, DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled); #endif retval = -EAGAIN; - if (atomic_read(&p->cred->user->processes) >= + if (atomic_read(&p->real_cred->user->processes) >= p->signal->rlim[RLIMIT_NPROC].rlim_cur) { if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) && - p->cred->user != current->nsproxy->user_ns->root_user) + p->real_cred->user != current->nsproxy->user_ns->root_user) goto bad_fork_free; } @@ -1278,6 +1279,7 @@ bad_fork_cleanup_put_domain: module_put(task_thread_info(p)->exec_domain->module); bad_fork_cleanup_count: atomic_dec(&p->cred->user->processes); + put_cred(p->real_cred); put_cred(p->cred); bad_fork_free: free_task(p); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 21a592184633..91b06f2aa963 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -161,7 +161,7 @@ static int selinux_secmark_enabled(void) */ static void cred_init_security(void) { - struct cred *cred = (struct cred *) current->cred; + struct cred *cred = (struct cred *) current->real_cred; struct task_security_struct *tsec; tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); @@ -184,7 +184,7 @@ static inline u32 cred_sid(const struct cred *cred) } /* - * get the security ID of a task + * get the objective security ID of a task */ static inline u32 task_sid(const struct task_struct *task) { @@ -197,7 +197,7 @@ static inline u32 task_sid(const struct task_struct *task) } /* - * get the security ID of the current task + * get the subjective security ID of the current task */ static inline u32 current_sid(void) { @@ -1395,6 +1395,7 @@ static int cred_has_perm(const struct cred *actor, * Check permission between a pair of tasks, e.g. signal checks, * fork check, ptrace check, etc. * tsk1 is the actor and tsk2 is the target + * - this uses the default subjective creds of tsk1 */ static int task_has_perm(const struct task_struct *tsk1, const struct task_struct *tsk2, @@ -1410,6 +1411,22 @@ static int task_has_perm(const struct task_struct *tsk1, return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL); } +/* + * Check permission between current and another task, e.g. signal checks, + * fork check, ptrace check, etc. + * current is the actor and tsk2 is the target + * - this uses current's subjective creds + */ +static int current_has_perm(const struct task_struct *tsk, + u32 perms) +{ + u32 sid, tsid; + + sid = current_sid(); + tsid = task_sid(tsk); + return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL); +} + #if CAP_LAST_CAP > 63 #error Fix SELinux to handle capabilities > 63. #endif @@ -1807,7 +1824,7 @@ static int selinux_ptrace_may_access(struct task_struct *child, return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL); } - return task_has_perm(current, child, PROCESS__PTRACE); + return current_has_perm(child, PROCESS__PTRACE); } static int selinux_ptrace_traceme(struct task_struct *parent) @@ -1826,7 +1843,7 @@ static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, { int error; - error = task_has_perm(current, target, PROCESS__GETCAP); + error = current_has_perm(target, PROCESS__GETCAP); if (error) return error; @@ -3071,7 +3088,7 @@ static int selinux_file_mprotect(struct vm_area_struct *vma, } else if (!vma->vm_file && vma->vm_start <= vma->vm_mm->start_stack && vma->vm_end >= vma->vm_mm->start_stack) { - rc = task_has_perm(current, current, PROCESS__EXECSTACK); + rc = current_has_perm(current, PROCESS__EXECSTACK); } else if (vma->vm_file && vma->anon_vma) { /* * We are making executable a file mapping that has @@ -3220,7 +3237,7 @@ static int selinux_task_create(unsigned long clone_flags) if (rc) return rc; - return task_has_perm(current, current, PROCESS__FORK); + return current_has_perm(current, PROCESS__FORK); } /* @@ -3285,17 +3302,17 @@ static int selinux_task_setgid(gid_t id0, gid_t id1, gid_t id2, int flags) static int selinux_task_setpgid(struct task_struct *p, pid_t pgid) { - return task_has_perm(current, p, PROCESS__SETPGID); + return current_has_perm(p, PROCESS__SETPGID); } static int selinux_task_getpgid(struct task_struct *p) { - return task_has_perm(current, p, PROCESS__GETPGID); + return current_has_perm(p, PROCESS__GETPGID); } static int selinux_task_getsid(struct task_struct *p) { - return task_has_perm(current, p, PROCESS__GETSESSION); + return current_has_perm(p, PROCESS__GETSESSION); } static void selinux_task_getsecid(struct task_struct *p, u32 *secid) @@ -3317,7 +3334,7 @@ static int selinux_task_setnice(struct task_struct *p, int nice) if (rc) return rc; - return task_has_perm(current, p, PROCESS__SETSCHED); + return current_has_perm(p, PROCESS__SETSCHED); } static int selinux_task_setioprio(struct task_struct *p, int ioprio) @@ -3328,12 +3345,12 @@ static int selinux_task_setioprio(struct task_struct *p, int ioprio) if (rc) return rc; - return task_has_perm(current, p, PROCESS__SETSCHED); + return current_has_perm(p, PROCESS__SETSCHED); } static int selinux_task_getioprio(struct task_struct *p) { - return task_has_perm(current, p, PROCESS__GETSCHED); + return current_has_perm(p, PROCESS__GETSCHED); } static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim) @@ -3350,7 +3367,7 @@ static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim later be used as a safe reset point for the soft limit upon context transitions. See selinux_bprm_committing_creds. */ if (old_rlim->rlim_max != new_rlim->rlim_max) - return task_has_perm(current, current, PROCESS__SETRLIMIT); + return current_has_perm(current, PROCESS__SETRLIMIT); return 0; } @@ -3363,17 +3380,17 @@ static int selinux_task_setscheduler(struct task_struct *p, int policy, struct s if (rc) return rc; - return task_has_perm(current, p, PROCESS__SETSCHED); + return current_has_perm(p, PROCESS__SETSCHED); } static int selinux_task_getscheduler(struct task_struct *p) { - return task_has_perm(current, p, PROCESS__GETSCHED); + return current_has_perm(p, PROCESS__GETSCHED); } static int selinux_task_movememory(struct task_struct *p) { - return task_has_perm(current, p, PROCESS__SETSCHED); + return current_has_perm(p, PROCESS__SETSCHED); } static int selinux_task_kill(struct task_struct *p, struct siginfo *info, @@ -3394,7 +3411,7 @@ static int selinux_task_kill(struct task_struct *p, struct siginfo *info, rc = avc_has_perm(secid, task_sid(p), SECCLASS_PROCESS, perm, NULL); else - rc = task_has_perm(current, p, perm); + rc = current_has_perm(p, perm); return rc; } @@ -5250,7 +5267,7 @@ static int selinux_getprocattr(struct task_struct *p, unsigned len; if (current != p) { - error = task_has_perm(current, p, PROCESS__GETATTR); + error = current_has_perm(p, PROCESS__GETATTR); if (error) return error; } @@ -5309,15 +5326,15 @@ static int selinux_setprocattr(struct task_struct *p, * above restriction is ever removed. */ if (!strcmp(name, "exec")) - error = task_has_perm(current, p, PROCESS__SETEXEC); + error = current_has_perm(p, PROCESS__SETEXEC); else if (!strcmp(name, "fscreate")) - error = task_has_perm(current, p, PROCESS__SETFSCREATE); + error = current_has_perm(p, PROCESS__SETFSCREATE); else if (!strcmp(name, "keycreate")) - error = task_has_perm(current, p, PROCESS__SETKEYCREATE); + error = current_has_perm(p, PROCESS__SETKEYCREATE); else if (!strcmp(name, "sockcreate")) - error = task_has_perm(current, p, PROCESS__SETSOCKCREATE); + error = current_has_perm(p, PROCESS__SETSOCKCREATE); else if (!strcmp(name, "current")) - error = task_has_perm(current, p, PROCESS__SETCURRENT); + error = current_has_perm(p, PROCESS__SETCURRENT); else error = -EINVAL; if (error) -- cgit v1.2.3 From 3a3b7ce9336952ea7b9564d976d068a238976c9d Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 14 Nov 2008 10:39:28 +1100 Subject: CRED: Allow kernel services to override LSM settings for task actions Allow kernel services to override LSM settings appropriate to the actions performed by a task by duplicating a set of credentials, modifying it and then using task_struct::cred to point to it when performing operations on behalf of a task. This is used, for example, by CacheFiles which has to transparently access the cache on behalf of a process that thinks it is doing, say, NFS accesses with a potentially inappropriate (with respect to accessing the cache) set of credentials. This patch provides two LSM hooks for modifying a task security record: (*) security_kernel_act_as() which allows modification of the security datum with which a task acts on other objects (most notably files). (*) security_kernel_create_files_as() which allows modification of the security datum that is used to initialise the security data on a file that a task creates. The patch also provides four new credentials handling functions, which wrap the LSM functions: (1) prepare_kernel_cred() Prepare a set of credentials for a kernel service to use, based either on a daemon's credentials or on init_cred. All the keyrings are cleared. (2) set_security_override() Set the LSM security ID in a set of credentials to a specific security context, assuming permission from the LSM policy. (3) set_security_override_from_ctx() As (2), but takes the security context as a string. (4) set_create_files_as() Set the file creation LSM security ID in a set of credentials to be the same as that on a particular inode. Signed-off-by: Casey Schaufler [Smack changes] Signed-off-by: David Howells Signed-off-by: James Morris --- include/linux/cred.h | 6 +++ include/linux/security.h | 28 +++++++++++ kernel/cred.c | 113 +++++++++++++++++++++++++++++++++++++++++++++ security/capability.c | 12 +++++ security/security.c | 10 ++++ security/selinux/hooks.c | 46 ++++++++++++++++++ security/smack/smack_lsm.c | 37 +++++++++++++++ 7 files changed, 252 insertions(+) (limited to 'include') diff --git a/include/linux/cred.h b/include/linux/cred.h index 55a9c995d694..26c1ab179946 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -18,6 +18,7 @@ struct user_struct; struct cred; +struct inode; /* * COW Supplementary groups list @@ -148,6 +149,11 @@ extern int commit_creds(struct cred *); extern void abort_creds(struct cred *); extern const struct cred *override_creds(const struct cred *); extern void revert_creds(const struct cred *); +extern struct cred *prepare_kernel_cred(struct task_struct *); +extern int change_create_files_as(struct cred *, struct inode *); +extern int set_security_override(struct cred *, u32); +extern int set_security_override_from_ctx(struct cred *, const char *); +extern int set_create_files_as(struct cred *, struct inode *); extern void __init cred_init(void); /** diff --git a/include/linux/security.h b/include/linux/security.h index 56a0eed65673..59a11e19b617 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -587,6 +587,19 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @new points to the new credentials. * @old points to the original credentials. * Install a new set of credentials. + * @kernel_act_as: + * Set the credentials for a kernel service to act as (subjective context). + * @new points to the credentials to be modified. + * @secid specifies the security ID to be set + * The current task must be the one that nominated @secid. + * Return 0 if successful. + * @kernel_create_files_as: + * Set the file creation context in a set of credentials to be the same as + * the objective context of the specified inode. + * @new points to the credentials to be modified. + * @inode points to the inode to use as a reference. + * The current task must be the one that nominated @inode. + * Return 0 if successful. * @task_setuid: * Check permission before setting one or more of the user identity * attributes of the current process. The @flags parameter indicates @@ -1381,6 +1394,8 @@ struct security_operations { int (*cred_prepare)(struct cred *new, const struct cred *old, gfp_t gfp); void (*cred_commit)(struct cred *new, const struct cred *old); + int (*kernel_act_as)(struct cred *new, u32 secid); + int (*kernel_create_files_as)(struct cred *new, struct inode *inode); int (*task_setuid) (uid_t id0, uid_t id1, uid_t id2, int flags); int (*task_fix_setuid) (struct cred *new, const struct cred *old, int flags); @@ -1632,6 +1647,8 @@ int security_task_create(unsigned long clone_flags); void security_cred_free(struct cred *cred); int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); void security_commit_creds(struct cred *new, const struct cred *old); +int security_kernel_act_as(struct cred *new, u32 secid); +int security_kernel_create_files_as(struct cred *new, struct inode *inode); int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags); int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags); @@ -2151,6 +2168,17 @@ static inline void security_commit_creds(struct cred *new, { } +static inline int security_kernel_act_as(struct cred *cred, u32 secid) +{ + return 0; +} + +static inline int security_kernel_create_files_as(struct cred *cred, + struct inode *inode) +{ + return 0; +} + static inline int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) { diff --git a/kernel/cred.c b/kernel/cred.c index f3ca10660617..13697ca2bb38 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -462,3 +462,116 @@ void __init cred_init(void) cred_jar = kmem_cache_create("cred_jar", sizeof(struct cred), 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); } + +/** + * prepare_kernel_cred - Prepare a set of credentials for a kernel service + * @daemon: A userspace daemon to be used as a reference + * + * Prepare a set of credentials for a kernel service. This can then be used to + * override a task's own credentials so that work can be done on behalf of that + * task that requires a different subjective context. + * + * @daemon is used to provide a base for the security record, but can be NULL. + * If @daemon is supplied, then the security data will be derived from that; + * otherwise they'll be set to 0 and no groups, full capabilities and no keys. + * + * The caller may change these controls afterwards if desired. + * + * Returns the new credentials or NULL if out of memory. + * + * Does not take, and does not return holding current->cred_replace_mutex. + */ +struct cred *prepare_kernel_cred(struct task_struct *daemon) +{ + const struct cred *old; + struct cred *new; + + new = kmem_cache_alloc(cred_jar, GFP_KERNEL); + if (!new) + return NULL; + + if (daemon) + old = get_task_cred(daemon); + else + old = get_cred(&init_cred); + + get_uid(new->user); + get_group_info(new->group_info); + +#ifdef CONFIG_KEYS + atomic_inc(&init_tgcred.usage); + new->tgcred = &init_tgcred; + new->request_key_auth = NULL; + new->thread_keyring = NULL; + new->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING; +#endif + +#ifdef CONFIG_SECURITY + new->security = NULL; +#endif + if (security_prepare_creds(new, old, GFP_KERNEL) < 0) + goto error; + + atomic_set(&new->usage, 1); + put_cred(old); + return new; + +error: + put_cred(new); + return NULL; +} +EXPORT_SYMBOL(prepare_kernel_cred); + +/** + * set_security_override - Set the security ID in a set of credentials + * @new: The credentials to alter + * @secid: The LSM security ID to set + * + * Set the LSM security ID in a set of credentials so that the subjective + * security is overridden when an alternative set of credentials is used. + */ +int set_security_override(struct cred *new, u32 secid) +{ + return security_kernel_act_as(new, secid); +} +EXPORT_SYMBOL(set_security_override); + +/** + * set_security_override_from_ctx - Set the security ID in a set of credentials + * @new: The credentials to alter + * @secctx: The LSM security context to generate the security ID from. + * + * Set the LSM security ID in a set of credentials so that the subjective + * security is overridden when an alternative set of credentials is used. The + * security ID is specified in string form as a security context to be + * interpreted by the LSM. + */ +int set_security_override_from_ctx(struct cred *new, const char *secctx) +{ + u32 secid; + int ret; + + ret = security_secctx_to_secid(secctx, strlen(secctx), &secid); + if (ret < 0) + return ret; + + return set_security_override(new, secid); +} +EXPORT_SYMBOL(set_security_override_from_ctx); + +/** + * set_create_files_as - Set the LSM file create context in a set of credentials + * @new: The credentials to alter + * @inode: The inode to take the context from + * + * Change the LSM file creation context in a set of credentials to be the same + * as the object context of the specified inode, so that the new inodes have + * the same MAC context as that inode. + */ +int set_create_files_as(struct cred *new, struct inode *inode) +{ + new->fsuid = inode->i_uid; + new->fsgid = inode->i_gid; + return security_kernel_create_files_as(new, inode); +} +EXPORT_SYMBOL(set_create_files_as); diff --git a/security/capability.c b/security/capability.c index 185804f99ad1..b9e391425e6f 100644 --- a/security/capability.c +++ b/security/capability.c @@ -348,6 +348,16 @@ static void cap_cred_commit(struct cred *new, const struct cred *old) { } +static int cap_kernel_act_as(struct cred *new, u32 secid) +{ + return 0; +} + +static int cap_kernel_create_files_as(struct cred *new, struct inode *inode) +{ + return 0; +} + static int cap_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) { return 0; @@ -889,6 +899,8 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, cred_free); set_to_cap_if_null(ops, cred_prepare); set_to_cap_if_null(ops, cred_commit); + set_to_cap_if_null(ops, kernel_act_as); + set_to_cap_if_null(ops, kernel_create_files_as); set_to_cap_if_null(ops, task_setuid); set_to_cap_if_null(ops, task_fix_setuid); set_to_cap_if_null(ops, task_setgid); diff --git a/security/security.c b/security/security.c index dc5babb2d6d8..038ef04b2c7f 100644 --- a/security/security.c +++ b/security/security.c @@ -616,6 +616,16 @@ void security_commit_creds(struct cred *new, const struct cred *old) return security_ops->cred_commit(new, old); } +int security_kernel_act_as(struct cred *new, u32 secid) +{ + return security_ops->kernel_act_as(new, secid); +} + +int security_kernel_create_files_as(struct cred *new, struct inode *inode) +{ + return security_ops->kernel_create_files_as(new, inode); +} + int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) { return security_ops->task_setuid(id0, id1, id2, flags); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 91b06f2aa963..520f82ab3fbf 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3277,6 +3277,50 @@ static void selinux_cred_commit(struct cred *new, const struct cred *old) secondary_ops->cred_commit(new, old); } +/* + * set the security data for a kernel service + * - all the creation contexts are set to unlabelled + */ +static int selinux_kernel_act_as(struct cred *new, u32 secid) +{ + struct task_security_struct *tsec = new->security; + u32 sid = current_sid(); + int ret; + + ret = avc_has_perm(sid, secid, + SECCLASS_KERNEL_SERVICE, + KERNEL_SERVICE__USE_AS_OVERRIDE, + NULL); + if (ret == 0) { + tsec->sid = secid; + tsec->create_sid = 0; + tsec->keycreate_sid = 0; + tsec->sockcreate_sid = 0; + } + return ret; +} + +/* + * set the file creation context in a security record to the same as the + * objective context of the specified inode + */ +static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode) +{ + struct inode_security_struct *isec = inode->i_security; + struct task_security_struct *tsec = new->security; + u32 sid = current_sid(); + int ret; + + ret = avc_has_perm(sid, isec->sid, + SECCLASS_KERNEL_SERVICE, + KERNEL_SERVICE__CREATE_FILES_AS, + NULL); + + if (ret == 0) + tsec->create_sid = isec->sid; + return 0; +} + static int selinux_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) { /* Since setuid only affects the current process, and @@ -5593,6 +5637,8 @@ static struct security_operations selinux_ops = { .cred_free = selinux_cred_free, .cred_prepare = selinux_cred_prepare, .cred_commit = selinux_cred_commit, + .kernel_act_as = selinux_kernel_act_as, + .kernel_create_files_as = selinux_kernel_create_files_as, .task_setuid = selinux_task_setuid, .task_fix_setuid = selinux_task_fix_setuid, .task_setgid = selinux_task_setgid, diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index de396742abf4..8ad48161cef5 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1011,6 +1011,41 @@ static void smack_cred_commit(struct cred *new, const struct cred *old) { } +/** + * smack_kernel_act_as - Set the subjective context in a set of credentials + * @new points to the set of credentials to be modified. + * @secid specifies the security ID to be set + * + * Set the security data for a kernel service. + */ +static int smack_kernel_act_as(struct cred *new, u32 secid) +{ + char *smack = smack_from_secid(secid); + + if (smack == NULL) + return -EINVAL; + + new->security = smack; + return 0; +} + +/** + * smack_kernel_create_files_as - Set the file creation label in a set of creds + * @new points to the set of credentials to be modified + * @inode points to the inode to use as a reference + * + * Set the file creation context in a set of credentials to the same + * as the objective context of the specified inode + */ +static int smack_kernel_create_files_as(struct cred *new, + struct inode *inode) +{ + struct inode_smack *isp = inode->i_security; + + new->security = isp->smk_inode; + return 0; +} + /** * smack_task_setpgid - Smack check on setting pgid * @p: the task object @@ -2641,6 +2676,8 @@ struct security_operations smack_ops = { .cred_free = smack_cred_free, .cred_prepare = smack_cred_prepare, .cred_commit = smack_cred_commit, + .kernel_act_as = smack_kernel_act_as, + .kernel_create_files_as = smack_kernel_create_files_as, .task_fix_setuid = cap_task_fix_setuid, .task_setpgid = smack_task_setpgid, .task_getpgid = smack_task_getpgid, -- cgit v1.2.3 From 18b6e0414e42d95183f07d8177e3ff0241abd825 Mon Sep 17 00:00:00 2001 From: Serge Hallyn Date: Wed, 15 Oct 2008 16:38:45 -0500 Subject: User namespaces: set of cleanups (v2) The user_ns is moved from nsproxy to user_struct, so that a struct cred by itself is sufficient to determine access (which it otherwise would not be). Corresponding ecryptfs fixes (by David Howells) are here as well. Fix refcounting. The following rules now apply: 1. The task pins the user struct. 2. The user struct pins its user namespace. 3. The user namespace pins the struct user which created it. User namespaces are cloned during copy_creds(). Unsharing a new user_ns is no longer possible. (We could re-add that, but it'll cause code duplication and doesn't seem useful if PAM doesn't need to clone user namespaces). When a user namespace is created, its first user (uid 0) gets empty keyrings and a clean group_info. This incorporates a previous patch by David Howells. Here is his original patch description: >I suggest adding the attached incremental patch. It makes the following >changes: > > (1) Provides a current_user_ns() macro to wrap accesses to current's user > namespace. > > (2) Fixes eCryptFS. > > (3) Renames create_new_userns() to create_user_ns() to be more consistent > with the other associated functions and because the 'new' in the name is > superfluous. > > (4) Moves the argument and permission checks made for CLONE_NEWUSER to the > beginning of do_fork() so that they're done prior to making any attempts > at allocation. > > (5) Calls create_user_ns() after prepare_creds(), and gives it the new creds > to fill in rather than have it return the new root user. I don't imagine > the new root user being used for anything other than filling in a cred > struct. > > This also permits me to get rid of a get_uid() and a free_uid(), as the > reference the creds were holding on the old user_struct can just be > transferred to the new namespace's creator pointer. > > (6) Makes create_user_ns() reset the UIDs and GIDs of the creds under > preparation rather than doing it in copy_creds(). > >David >Signed-off-by: David Howells Changelog: Oct 20: integrate dhowells comments 1. leave thread_keyring alone 2. use current_user_ns() in set_user() Signed-off-by: Serge Hallyn --- fs/ecryptfs/messaging.c | 13 ++++---- fs/ecryptfs/miscdev.c | 19 ++++------- include/linux/cred.h | 2 ++ include/linux/init_task.h | 1 - include/linux/nsproxy.h | 1 - include/linux/sched.h | 1 + include/linux/user_namespace.h | 13 +++----- kernel/cred.c | 15 +++++++-- kernel/fork.c | 19 +++++++++-- kernel/nsproxy.c | 15 ++------- kernel/sys.c | 4 +-- kernel/user.c | 47 ++++++++------------------ kernel/user_namespace.c | 75 +++++++++++++++++------------------------- 13 files changed, 96 insertions(+), 129 deletions(-) (limited to 'include') diff --git a/fs/ecryptfs/messaging.c b/fs/ecryptfs/messaging.c index e0b0a4e28b9b..6913f727624d 100644 --- a/fs/ecryptfs/messaging.c +++ b/fs/ecryptfs/messaging.c @@ -360,7 +360,7 @@ int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid, struct ecryptfs_msg_ctx *msg_ctx; size_t msg_size; struct nsproxy *nsproxy; - struct user_namespace *current_user_ns; + struct user_namespace *tsk_user_ns; uid_t ctx_euid; int rc; @@ -385,9 +385,9 @@ int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid, mutex_unlock(&ecryptfs_daemon_hash_mux); goto wake_up; } - current_user_ns = nsproxy->user_ns; + tsk_user_ns = __task_cred(msg_ctx->task)->user->user_ns; ctx_euid = task_euid(msg_ctx->task); - rc = ecryptfs_find_daemon_by_euid(&daemon, ctx_euid, current_user_ns); + rc = ecryptfs_find_daemon_by_euid(&daemon, ctx_euid, tsk_user_ns); rcu_read_unlock(); mutex_unlock(&ecryptfs_daemon_hash_mux); if (rc) { @@ -405,11 +405,11 @@ int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid, euid, ctx_euid); goto unlock; } - if (current_user_ns != user_ns) { + if (tsk_user_ns != user_ns) { rc = -EBADMSG; printk(KERN_WARNING "%s: Received message from user_ns " "[0x%p]; expected message from user_ns [0x%p]\n", - __func__, user_ns, nsproxy->user_ns); + __func__, user_ns, tsk_user_ns); goto unlock; } if (daemon->pid != pid) { @@ -468,8 +468,7 @@ ecryptfs_send_message_locked(char *data, int data_len, u8 msg_type, uid_t euid = current_euid(); int rc; - rc = ecryptfs_find_daemon_by_euid(&daemon, euid, - current->nsproxy->user_ns); + rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); if (rc || !daemon) { rc = -ENOTCONN; printk(KERN_ERR "%s: User [%d] does not have a daemon " diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c index 047ac609695b..efd95a0ed1ea 100644 --- a/fs/ecryptfs/miscdev.c +++ b/fs/ecryptfs/miscdev.c @@ -47,8 +47,7 @@ ecryptfs_miscdev_poll(struct file *file, poll_table *pt) mutex_lock(&ecryptfs_daemon_hash_mux); /* TODO: Just use file->private_data? */ - rc = ecryptfs_find_daemon_by_euid(&daemon, euid, - current->nsproxy->user_ns); + rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); BUG_ON(rc || !daemon); mutex_lock(&daemon->mux); mutex_unlock(&ecryptfs_daemon_hash_mux); @@ -95,11 +94,9 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file) "count; rc = [%d]\n", __func__, rc); goto out_unlock_daemon_list; } - rc = ecryptfs_find_daemon_by_euid(&daemon, euid, - current->nsproxy->user_ns); + rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); if (rc || !daemon) { - rc = ecryptfs_spawn_daemon(&daemon, euid, - current->nsproxy->user_ns, + rc = ecryptfs_spawn_daemon(&daemon, euid, current_user_ns(), task_pid(current)); if (rc) { printk(KERN_ERR "%s: Error attempting to spawn daemon; " @@ -153,8 +150,7 @@ ecryptfs_miscdev_release(struct inode *inode, struct file *file) int rc; mutex_lock(&ecryptfs_daemon_hash_mux); - rc = ecryptfs_find_daemon_by_euid(&daemon, euid, - current->nsproxy->user_ns); + rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); BUG_ON(rc || !daemon); mutex_lock(&daemon->mux); BUG_ON(daemon->pid != task_pid(current)); @@ -254,8 +250,7 @@ ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count, mutex_lock(&ecryptfs_daemon_hash_mux); /* TODO: Just use file->private_data? */ - rc = ecryptfs_find_daemon_by_euid(&daemon, euid, - current->nsproxy->user_ns); + rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); BUG_ON(rc || !daemon); mutex_lock(&daemon->mux); if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { @@ -295,7 +290,7 @@ check_list: goto check_list; } BUG_ON(euid != daemon->euid); - BUG_ON(current->nsproxy->user_ns != daemon->user_ns); + BUG_ON(current_user_ns() != daemon->user_ns); BUG_ON(task_pid(current) != daemon->pid); msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue, struct ecryptfs_msg_ctx, daemon_out_list); @@ -468,7 +463,7 @@ ecryptfs_miscdev_write(struct file *file, const char __user *buf, goto out_free; } rc = ecryptfs_miscdev_response(&data[i], packet_size, - euid, current->nsproxy->user_ns, + euid, current_user_ns(), task_pid(current), seq); if (rc) printk(KERN_WARNING "%s: Failed to deliver miscdev " diff --git a/include/linux/cred.h b/include/linux/cred.h index 26c1ab179946..3282ee4318e7 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -60,6 +60,7 @@ do { \ } while (0) extern struct group_info *groups_alloc(int); +extern struct group_info init_groups; extern void groups_free(struct group_info *); extern int set_current_groups(struct group_info *); extern int set_groups(struct cred *, struct group_info *); @@ -315,6 +316,7 @@ static inline void put_cred(const struct cred *_cred) #define current_fsgid() (current_cred_xxx(fsgid)) #define current_cap() (current_cred_xxx(cap_effective)) #define current_user() (current_cred_xxx(user)) +#define current_user_ns() (current_cred_xxx(user)->user_ns) #define current_security() (current_cred_xxx(security)) #define current_uid_gid(_uid, _gid) \ diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 2597858035cd..959f5522d10a 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -57,7 +57,6 @@ extern struct nsproxy init_nsproxy; .mnt_ns = NULL, \ INIT_NET_NS(net_ns) \ INIT_IPC_NS(ipc_ns) \ - .user_ns = &init_user_ns, \ } #define INIT_SIGHAND(sighand) { \ diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h index c8a768e59640..afad7dec1b36 100644 --- a/include/linux/nsproxy.h +++ b/include/linux/nsproxy.h @@ -27,7 +27,6 @@ struct nsproxy { struct ipc_namespace *ipc_ns; struct mnt_namespace *mnt_ns; struct pid_namespace *pid_ns; - struct user_namespace *user_ns; struct net *net_ns; }; extern struct nsproxy init_nsproxy; diff --git a/include/linux/sched.h b/include/linux/sched.h index 2036e9f26020..7f8015a3082e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -638,6 +638,7 @@ struct user_struct { /* Hash table maintenance information */ struct hlist_node uidhash_node; uid_t uid; + struct user_namespace *user_ns; #ifdef CONFIG_USER_SCHED struct task_group *tg; diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index b5f41d4c2eec..315bcd375224 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -12,7 +12,7 @@ struct user_namespace { struct kref kref; struct hlist_head uidhash_table[UIDHASH_SZ]; - struct user_struct *root_user; + struct user_struct *creator; }; extern struct user_namespace init_user_ns; @@ -26,8 +26,7 @@ static inline struct user_namespace *get_user_ns(struct user_namespace *ns) return ns; } -extern struct user_namespace *copy_user_ns(int flags, - struct user_namespace *old_ns); +extern int create_user_ns(struct cred *new); extern void free_user_ns(struct kref *kref); static inline void put_user_ns(struct user_namespace *ns) @@ -43,13 +42,9 @@ static inline struct user_namespace *get_user_ns(struct user_namespace *ns) return &init_user_ns; } -static inline struct user_namespace *copy_user_ns(int flags, - struct user_namespace *old_ns) +static inline int create_user_ns(struct cred *new) { - if (flags & CLONE_NEWUSER) - return ERR_PTR(-EINVAL); - - return old_ns; + return -EINVAL; } static inline void put_user_ns(struct user_namespace *ns) diff --git a/kernel/cred.c b/kernel/cred.c index 13697ca2bb38..ff7bc071991c 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -274,6 +274,7 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) struct thread_group_cred *tgcred; #endif struct cred *new; + int ret; mutex_init(&p->cred_exec_mutex); @@ -293,6 +294,12 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) if (!new) return -ENOMEM; + if (clone_flags & CLONE_NEWUSER) { + ret = create_user_ns(new); + if (ret < 0) + goto error_put; + } + #ifdef CONFIG_KEYS /* new threads get their own thread keyrings if their parent already * had one */ @@ -309,8 +316,8 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) if (!(clone_flags & CLONE_THREAD)) { tgcred = kmalloc(sizeof(*tgcred), GFP_KERNEL); if (!tgcred) { - put_cred(new); - return -ENOMEM; + ret = -ENOMEM; + goto error_put; } atomic_set(&tgcred->usage, 1); spin_lock_init(&tgcred->lock); @@ -325,6 +332,10 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) atomic_inc(&new->user->processes); p->cred = p->real_cred = get_cred(new); return 0; + +error_put: + put_cred(new); + return ret; } /** diff --git a/kernel/fork.c b/kernel/fork.c index 29c18c14812d..1dd89451fae4 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -976,7 +976,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, if (atomic_read(&p->real_cred->user->processes) >= p->signal->rlim[RLIMIT_NPROC].rlim_cur) { if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) && - p->real_cred->user != current->nsproxy->user_ns->root_user) + p->real_cred->user != INIT_USER) goto bad_fork_free; } @@ -1334,6 +1334,20 @@ long do_fork(unsigned long clone_flags, int trace = 0; long nr; + /* + * Do some preliminary argument and permissions checking before we + * actually start allocating stuff + */ + if (clone_flags & CLONE_NEWUSER) { + if (clone_flags & CLONE_THREAD) + return -EINVAL; + /* hopefully this check will go away when userns support is + * complete + */ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + } + /* * We hope to recycle these flags after 2.6.26 */ @@ -1581,8 +1595,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) err = -EINVAL; if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND| CLONE_VM|CLONE_FILES|CLONE_SYSVSEM| - CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWUSER| - CLONE_NEWNET)) + CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET)) goto bad_unshare_out; /* diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 1d3ef29a2583..63598dca2d0c 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -80,12 +80,6 @@ static struct nsproxy *create_new_namespaces(unsigned long flags, goto out_pid; } - new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns); - if (IS_ERR(new_nsp->user_ns)) { - err = PTR_ERR(new_nsp->user_ns); - goto out_user; - } - new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns); if (IS_ERR(new_nsp->net_ns)) { err = PTR_ERR(new_nsp->net_ns); @@ -95,9 +89,6 @@ static struct nsproxy *create_new_namespaces(unsigned long flags, return new_nsp; out_net: - if (new_nsp->user_ns) - put_user_ns(new_nsp->user_ns); -out_user: if (new_nsp->pid_ns) put_pid_ns(new_nsp->pid_ns); out_pid: @@ -130,7 +121,7 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk) get_nsproxy(old_ns); if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | - CLONE_NEWUSER | CLONE_NEWPID | CLONE_NEWNET))) + CLONE_NEWPID | CLONE_NEWNET))) return 0; if (!capable(CAP_SYS_ADMIN)) { @@ -173,8 +164,6 @@ void free_nsproxy(struct nsproxy *ns) put_ipc_ns(ns->ipc_ns); if (ns->pid_ns) put_pid_ns(ns->pid_ns); - if (ns->user_ns) - put_user_ns(ns->user_ns); put_net(ns->net_ns); kmem_cache_free(nsproxy_cachep, ns); } @@ -189,7 +178,7 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags, int err = 0; if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | - CLONE_NEWUSER | CLONE_NEWNET))) + CLONE_NEWNET))) return 0; if (!capable(CAP_SYS_ADMIN)) diff --git a/kernel/sys.c b/kernel/sys.c index ab735040468a..ebe65c2c9873 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -565,13 +565,13 @@ static int set_user(struct cred *new) { struct user_struct *new_user; - new_user = alloc_uid(current->nsproxy->user_ns, new->uid); + new_user = alloc_uid(current_user_ns(), new->uid); if (!new_user) return -EAGAIN; if (atomic_read(&new_user->processes) >= current->signal->rlim[RLIMIT_NPROC].rlim_cur && - new_user != current->nsproxy->user_ns->root_user) { + new_user != INIT_USER) { free_uid(new_user); return -EAGAIN; } diff --git a/kernel/user.c b/kernel/user.c index d476307dd4b0..c0ef3a464438 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -20,9 +20,9 @@ struct user_namespace init_user_ns = { .kref = { - .refcount = ATOMIC_INIT(2), + .refcount = ATOMIC_INIT(1), }, - .root_user = &root_user, + .creator = &root_user, }; EXPORT_SYMBOL_GPL(init_user_ns); @@ -48,12 +48,14 @@ static struct kmem_cache *uid_cachep; */ static DEFINE_SPINLOCK(uidhash_lock); +/* root_user.__count is 2, 1 for init task cred, 1 for init_user_ns->creator */ struct user_struct root_user = { - .__count = ATOMIC_INIT(1), + .__count = ATOMIC_INIT(2), .processes = ATOMIC_INIT(1), .files = ATOMIC_INIT(0), .sigpending = ATOMIC_INIT(0), .locked_shm = 0, + .user_ns = &init_user_ns, #ifdef CONFIG_USER_SCHED .tg = &init_task_group, #endif @@ -314,12 +316,13 @@ done: * IRQ state (as stored in flags) is restored and uidhash_lock released * upon function exit. */ -static inline void free_user(struct user_struct *up, unsigned long flags) +static void free_user(struct user_struct *up, unsigned long flags) { /* restore back the count */ atomic_inc(&up->__count); spin_unlock_irqrestore(&uidhash_lock, flags); + put_user_ns(up->user_ns); INIT_WORK(&up->work, remove_user_sysfs_dir); schedule_work(&up->work); } @@ -335,13 +338,14 @@ static inline void uids_mutex_unlock(void) { } * IRQ state (as stored in flags) is restored and uidhash_lock released * upon function exit. */ -static inline void free_user(struct user_struct *up, unsigned long flags) +static void free_user(struct user_struct *up, unsigned long flags) { uid_hash_remove(up); spin_unlock_irqrestore(&uidhash_lock, flags); sched_destroy_user(up); key_put(up->uid_keyring); key_put(up->session_keyring); + put_user_ns(up->user_ns); kmem_cache_free(uid_cachep, up); } @@ -357,7 +361,7 @@ struct user_struct *find_user(uid_t uid) { struct user_struct *ret; unsigned long flags; - struct user_namespace *ns = current->nsproxy->user_ns; + struct user_namespace *ns = current_user()->user_ns; spin_lock_irqsave(&uidhash_lock, flags); ret = uid_hash_find(uid, uidhashentry(ns, uid)); @@ -404,6 +408,8 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) if (sched_create_user(new) < 0) goto out_free_user; + new->user_ns = get_user_ns(ns); + if (uids_user_create(new)) goto out_destoy_sched; @@ -427,7 +433,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) up = new; } spin_unlock_irq(&uidhash_lock); - } uids_mutex_unlock(); @@ -436,6 +441,7 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) out_destoy_sched: sched_destroy_user(new); + put_user_ns(new->user_ns); out_free_user: kmem_cache_free(uid_cachep, new); out_unlock: @@ -443,33 +449,6 @@ out_unlock: return NULL; } -#ifdef CONFIG_USER_NS -void release_uids(struct user_namespace *ns) -{ - int i; - unsigned long flags; - struct hlist_head *head; - struct hlist_node *nd; - - spin_lock_irqsave(&uidhash_lock, flags); - /* - * collapse the chains so that the user_struct-s will - * be still alive, but not in hashes. subsequent free_uid() - * will free them. - */ - for (i = 0; i < UIDHASH_SZ; i++) { - head = ns->uidhash_table + i; - while (!hlist_empty(head)) { - nd = head->first; - hlist_del_init(nd); - } - } - spin_unlock_irqrestore(&uidhash_lock, flags); - - free_uid(ns->root_user); -} -#endif - static int __init uid_cache_init(void) { int n; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 0d9c51d67333..79084311ee57 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -9,70 +9,55 @@ #include #include #include +#include /* - * Clone a new ns copying an original user ns, setting refcount to 1 - * @old_ns: namespace to clone - * Return NULL on error (failure to kmalloc), new ns otherwise + * Create a new user namespace, deriving the creator from the user in the + * passed credentials, and replacing that user with the new root user for the + * new namespace. + * + * This is called by copy_creds(), which will finish setting the target task's + * credentials. */ -static struct user_namespace *clone_user_ns(struct user_namespace *old_ns) +int create_user_ns(struct cred *new) { struct user_namespace *ns; - struct user_struct *new_user; - struct cred *new; + struct user_struct *root_user; int n; ns = kmalloc(sizeof(struct user_namespace), GFP_KERNEL); if (!ns) - return ERR_PTR(-ENOMEM); + return -ENOMEM; kref_init(&ns->kref); for (n = 0; n < UIDHASH_SZ; ++n) INIT_HLIST_HEAD(ns->uidhash_table + n); - /* Insert new root user. */ - ns->root_user = alloc_uid(ns, 0); - if (!ns->root_user) { + /* Alloc new root user. */ + root_user = alloc_uid(ns, 0); + if (!root_user) { kfree(ns); - return ERR_PTR(-ENOMEM); + return -ENOMEM; } - /* Reset current->user with a new one */ - new_user = alloc_uid(ns, current_uid()); - if (!new_user) { - free_uid(ns->root_user); - kfree(ns); - return ERR_PTR(-ENOMEM); - } - - /* Install the new user */ - new = prepare_creds(); - if (!new) { - free_uid(new_user); - free_uid(ns->root_user); - kfree(ns); - } - free_uid(new->user); - new->user = new_user; - commit_creds(new); - return ns; -} - -struct user_namespace * copy_user_ns(int flags, struct user_namespace *old_ns) -{ - struct user_namespace *new_ns; - - BUG_ON(!old_ns); - get_user_ns(old_ns); - - if (!(flags & CLONE_NEWUSER)) - return old_ns; + /* set the new root user in the credentials under preparation */ + ns->creator = new->user; + new->user = root_user; + new->uid = new->euid = new->suid = new->fsuid = 0; + new->gid = new->egid = new->sgid = new->fsgid = 0; + put_group_info(new->group_info); + new->group_info = get_group_info(&init_groups); +#ifdef CONFIG_KEYS + key_put(new->request_key_auth); + new->request_key_auth = NULL; +#endif + /* tgcred will be cleared in our caller bc CLONE_THREAD won't be set */ - new_ns = clone_user_ns(old_ns); + /* alloc_uid() incremented the userns refcount. Just set it to 1 */ + kref_set(&ns->kref, 1); - put_user_ns(old_ns); - return new_ns; + return 0; } void free_user_ns(struct kref *kref) @@ -80,7 +65,7 @@ void free_user_ns(struct kref *kref) struct user_namespace *ns; ns = container_of(kref, struct user_namespace, kref); - release_uids(ns); + free_uid(ns->creator); kfree(ns); } EXPORT_SYMBOL(free_user_ns); -- cgit v1.2.3 From 1e641743f055f075ed9a4edd75f1fb1e05669ddc Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 9 Dec 2008 09:23:33 +0000 Subject: Audit: Log TIOCSTI AUDIT_TTY records currently log all data read by processes marked for TTY input auditing, even if the data was "pushed back" using the TIOCSTI ioctl, not typed by the user. This patch records all TIOCSTI calls to disambiguate the input. It generates one audit message per character pushed back; considering TIOCSTI is used very rarely, this simple solution is probably good enough. (The only program I could find that uses TIOCSTI is mailx/nail in "header editing" mode, e.g. using the ~h escape. mailx is used very rarely, and the escapes are used even rarer.) Signed-Off-By: Miloslav Trmac Signed-off-by: Al Viro Signed-off-by: James Morris --- drivers/char/tty_audit.c | 78 +++++++++++++++++++++++++++++++++++++----------- drivers/char/tty_io.c | 1 + include/linux/tty.h | 4 +++ 3 files changed, 66 insertions(+), 17 deletions(-) (limited to 'include') diff --git a/drivers/char/tty_audit.c b/drivers/char/tty_audit.c index d961fa9612c4..34ab6d798f81 100644 --- a/drivers/char/tty_audit.c +++ b/drivers/char/tty_audit.c @@ -67,37 +67,45 @@ static void tty_audit_buf_put(struct tty_audit_buf *buf) tty_audit_buf_free(buf); } -/** - * tty_audit_buf_push - Push buffered data out - * - * Generate an audit message from the contents of @buf, which is owned by - * @tsk with @loginuid. @buf->mutex must be locked. - */ -static void tty_audit_buf_push(struct task_struct *tsk, uid_t loginuid, - unsigned int sessionid, - struct tty_audit_buf *buf) +static void tty_audit_log(const char *description, struct task_struct *tsk, + uid_t loginuid, unsigned sessionid, int major, + int minor, unsigned char *data, size_t size) { struct audit_buffer *ab; - if (buf->valid == 0) - return; - if (audit_enabled == 0) - return; ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_TTY); if (ab) { char name[sizeof(tsk->comm)]; uid_t uid = task_uid(tsk); - audit_log_format(ab, "tty pid=%u uid=%u auid=%u ses=%u " - "major=%d minor=%d comm=", + audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u " + "major=%d minor=%d comm=", description, tsk->pid, uid, loginuid, sessionid, - buf->major, buf->minor); + major, minor); get_task_comm(name, tsk); audit_log_untrustedstring(ab, name); audit_log_format(ab, " data="); - audit_log_n_hex(ab, buf->data, buf->valid); + audit_log_n_hex(ab, data, size); audit_log_end(ab); } +} + +/** + * tty_audit_buf_push - Push buffered data out + * + * Generate an audit message from the contents of @buf, which is owned by + * @tsk with @loginuid. @buf->mutex must be locked. + */ +static void tty_audit_buf_push(struct task_struct *tsk, uid_t loginuid, + unsigned int sessionid, + struct tty_audit_buf *buf) +{ + if (buf->valid == 0) + return; + if (audit_enabled == 0) + return; + tty_audit_log("tty", tsk, loginuid, sessionid, buf->major, buf->minor, + buf->data, buf->valid); buf->valid = 0; } @@ -151,6 +159,42 @@ void tty_audit_fork(struct signal_struct *sig) sig->tty_audit_buf = NULL; } +/** + * tty_audit_tiocsti - Log TIOCSTI + */ +void tty_audit_tiocsti(struct tty_struct *tty, char ch) +{ + struct tty_audit_buf *buf; + int major, minor, should_audit; + + spin_lock_irq(¤t->sighand->siglock); + should_audit = current->signal->audit_tty; + buf = current->signal->tty_audit_buf; + if (buf) + atomic_inc(&buf->count); + spin_unlock_irq(¤t->sighand->siglock); + + major = tty->driver->major; + minor = tty->driver->minor_start + tty->index; + if (buf) { + mutex_lock(&buf->mutex); + if (buf->major == major && buf->minor == minor) + tty_audit_buf_push_current(buf); + mutex_unlock(&buf->mutex); + tty_audit_buf_put(buf); + } + + if (should_audit && audit_enabled) { + uid_t auid; + unsigned int sessionid; + + auid = audit_get_loginuid(current); + sessionid = audit_get_sessionid(current); + tty_audit_log("ioctl=TIOCSTI", current, auid, sessionid, major, + minor, &ch, 1); + } +} + /** * tty_audit_push_task - Flush task's pending audit data */ diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 1412a8d1e58d..db15f9ba7c0b 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -2018,6 +2018,7 @@ static int tiocsti(struct tty_struct *tty, char __user *p) return -EPERM; if (get_user(ch, p)) return -EFAULT; + tty_audit_tiocsti(tty, ch); ld = tty_ldisc_ref_wait(tty); ld->ops->receive_buf(tty, &ch, &mbz, 1); tty_ldisc_deref(ld); diff --git a/include/linux/tty.h b/include/linux/tty.h index 3b8121d4e36f..580700f20a1c 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -442,6 +442,7 @@ extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, size_t size); extern void tty_audit_exit(void); extern void tty_audit_fork(struct signal_struct *sig); +extern void tty_audit_tiocsti(struct tty_struct *tty, char ch); extern void tty_audit_push(struct tty_struct *tty); extern void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid); @@ -450,6 +451,9 @@ static inline void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, size_t size) { } +static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch) +{ +} static inline void tty_audit_exit(void) { } -- cgit v1.2.3 From 12204e24b1330428c3062faee10a0d80b8a5cb61 Mon Sep 17 00:00:00 2001 From: James Morris Date: Fri, 19 Dec 2008 10:44:42 +1100 Subject: security: pass mount flags to security_sb_kern_mount() Pass mount flags to security_sb_kern_mount(), so security modules can determine if a mount operation is being performed by the kernel. Signed-off-by: James Morris Acked-by: Stephen Smalley --- fs/super.c | 2 +- include/linux/security.h | 6 +++--- security/capability.c | 2 +- security/security.c | 4 ++-- security/selinux/hooks.c | 2 +- security/smack/smack_lsm.c | 3 ++- 6 files changed, 10 insertions(+), 9 deletions(-) (limited to 'include') diff --git a/fs/super.c b/fs/super.c index 400a7608f15e..ddba069d7a99 100644 --- a/fs/super.c +++ b/fs/super.c @@ -914,7 +914,7 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void goto out_free_secdata; BUG_ON(!mnt->mnt_sb); - error = security_sb_kern_mount(mnt->mnt_sb, secdata); + error = security_sb_kern_mount(mnt->mnt_sb, flags, secdata); if (error) goto out_sb; diff --git a/include/linux/security.h b/include/linux/security.h index 6423abf1ac0f..3416cb85e77b 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1308,7 +1308,7 @@ struct security_operations { int (*sb_alloc_security) (struct super_block *sb); void (*sb_free_security) (struct super_block *sb); int (*sb_copy_data) (char *orig, char *copy); - int (*sb_kern_mount) (struct super_block *sb, void *data); + int (*sb_kern_mount) (struct super_block *sb, int flags, void *data); int (*sb_show_options) (struct seq_file *m, struct super_block *sb); int (*sb_statfs) (struct dentry *dentry); int (*sb_mount) (char *dev_name, struct path *path, @@ -1575,7 +1575,7 @@ int security_bprm_secureexec(struct linux_binprm *bprm); int security_sb_alloc(struct super_block *sb); void security_sb_free(struct super_block *sb); int security_sb_copy_data(char *orig, char *copy); -int security_sb_kern_mount(struct super_block *sb, void *data); +int security_sb_kern_mount(struct super_block *sb, int flags, void *data); int security_sb_show_options(struct seq_file *m, struct super_block *sb); int security_sb_statfs(struct dentry *dentry); int security_sb_mount(char *dev_name, struct path *path, @@ -1850,7 +1850,7 @@ static inline int security_sb_copy_data(char *orig, char *copy) return 0; } -static inline int security_sb_kern_mount(struct super_block *sb, void *data) +static inline int security_sb_kern_mount(struct super_block *sb, int flags, void *data) { return 0; } diff --git a/security/capability.c b/security/capability.c index b9e391425e6f..2dce66fcb992 100644 --- a/security/capability.c +++ b/security/capability.c @@ -59,7 +59,7 @@ static int cap_sb_copy_data(char *orig, char *copy) return 0; } -static int cap_sb_kern_mount(struct super_block *sb, void *data) +static int cap_sb_kern_mount(struct super_block *sb, int flags, void *data) { return 0; } diff --git a/security/security.c b/security/security.c index f0d96a6cc4e9..d85dbb37c972 100644 --- a/security/security.c +++ b/security/security.c @@ -254,9 +254,9 @@ int security_sb_copy_data(char *orig, char *copy) } EXPORT_SYMBOL(security_sb_copy_data); -int security_sb_kern_mount(struct super_block *sb, void *data) +int security_sb_kern_mount(struct super_block *sb, int flags, void *data) { - return security_ops->sb_kern_mount(sb, data); + return security_ops->sb_kern_mount(sb, flags, data); } int security_sb_show_options(struct seq_file *m, struct super_block *sb) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 8dbc54cde59e..7465d713b531 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2474,7 +2474,7 @@ out: return rc; } -static int selinux_sb_kern_mount(struct super_block *sb, void *data) +static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data) { const struct cred *cred = current_cred(); struct avc_audit_data ad; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 8ad48161cef5..1b5551dfc1f7 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -250,11 +250,12 @@ static int smack_sb_copy_data(char *orig, char *smackopts) /** * smack_sb_kern_mount - Smack specific mount processing * @sb: the file system superblock + * @flags: the mount flags * @data: the smack mount options * * Returns 0 on success, an error code on failure */ -static int smack_sb_kern_mount(struct super_block *sb, void *data) +static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) { struct dentry *root = sb->s_root; struct inode *inode = root->d_inode; -- cgit v1.2.3