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-rw-r--r--include/linux/cred.h59
-rw-r--r--include/linux/fs.h2
-rw-r--r--include/linux/lsm_hook_defs.h10
-rw-r--r--include/linux/security.h20
-rw-r--r--kernel/cred.c26
-rw-r--r--security/apparmor/lsm.c4
-rw-r--r--security/commoncap.c4
-rw-r--r--security/security.c12
-rw-r--r--security/selinux/hooks.c10
-rw-r--r--security/tomoyo/tomoyo.c2
10 files changed, 97 insertions, 52 deletions
diff --git a/include/linux/cred.h b/include/linux/cred.h
index 92f8d772da6f..af8d353a4b86 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -220,6 +220,20 @@ static inline bool cap_ambient_invariant_ok(const struct cred *cred)
}
/**
+ * get_new_cred_many - Get references on a new set of credentials
+ * @cred: The new credentials to reference
+ * @nr: Number of references to acquire
+ *
+ * Get references on the specified set of new credentials. The caller must
+ * release all acquired references.
+ */
+static inline struct cred *get_new_cred_many(struct cred *cred, int nr)
+{
+ atomic_add(nr, &cred->usage);
+ return cred;
+}
+
+/**
* get_new_cred - Get a reference on a new set of credentials
* @cred: The new credentials to reference
*
@@ -228,16 +242,16 @@ static inline bool cap_ambient_invariant_ok(const struct cred *cred)
*/
static inline struct cred *get_new_cred(struct cred *cred)
{
- atomic_inc(&cred->usage);
- return cred;
+ return get_new_cred_many(cred, 1);
}
/**
- * get_cred - Get a reference on a set of credentials
+ * get_cred_many - Get references on a set of credentials
* @cred: The credentials to reference
+ * @nr: Number of references to acquire
*
- * Get a reference on the specified set of credentials. The caller must
- * release the reference. If %NULL is passed, it is returned with no action.
+ * Get references on the specified set of credentials. The caller must release
+ * all acquired reference. If %NULL is passed, it is returned with no action.
*
* 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
@@ -245,14 +259,28 @@ static inline struct cred *get_new_cred(struct cred *cred)
* accidental alteration of a set of credentials that should be considered
* immutable.
*/
-static inline const struct cred *get_cred(const struct cred *cred)
+static inline const struct cred *get_cred_many(const struct cred *cred, int nr)
{
struct cred *nonconst_cred = (struct cred *) cred;
if (!cred)
return cred;
validate_creds(cred);
nonconst_cred->non_rcu = 0;
- return get_new_cred(nonconst_cred);
+ return get_new_cred_many(nonconst_cred, nr);
+}
+
+/*
+ * 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. If %NULL is passed, it is returned with no action.
+ *
+ * This is used to deal with a committed set of credentials.
+ */
+static inline const struct cred *get_cred(const struct cred *cred)
+{
+ return get_cred_many(cred, 1);
}
static inline const struct cred *get_cred_rcu(const struct cred *cred)
@@ -270,6 +298,7 @@ static inline const struct cred *get_cred_rcu(const struct cred *cred)
/**
* put_cred - Release a reference to a set of credentials
* @cred: The credentials to release
+ * @nr: Number of references to release
*
* Release a reference to a set of credentials, deleting them when the last ref
* is released. If %NULL is passed, nothing is done.
@@ -278,17 +307,29 @@ static inline const struct cred *get_cred_rcu(const struct cred *cred)
* 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)
+static inline void put_cred_many(const struct cred *_cred, int nr)
{
struct cred *cred = (struct cred *) _cred;
if (cred) {
validate_creds(cred);
- if (atomic_dec_and_test(&(cred)->usage))
+ if (atomic_sub_and_test(nr, &cred->usage))
__put_cred(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. If %NULL is passed, nothing is done.
+ */
+static inline void put_cred(const struct cred *cred)
+{
+ put_cred_many(cred, 1);
+}
+
/**
* current_cred - Access the current task's subjective credentials
*
diff --git a/include/linux/fs.h b/include/linux/fs.h
index bd522c0ac267..c27c324ba58a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2478,7 +2478,7 @@ struct filename {
};
static_assert(offsetof(struct filename, iname) % sizeof(long) == 0);
-static inline struct mnt_idmap *file_mnt_idmap(struct file *file)
+static inline struct mnt_idmap *file_mnt_idmap(const struct file *file)
{
return mnt_idmap(file->f_path.mnt);
}
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index ac962c4cb44b..99b8176c3738 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -43,17 +43,17 @@ LSM_HOOK(int, 0, capset, struct cred *new, const struct cred *old,
const kernel_cap_t *permitted)
LSM_HOOK(int, 0, capable, const struct cred *cred, struct user_namespace *ns,
int cap, unsigned int opts)
-LSM_HOOK(int, 0, quotactl, int cmds, int type, int id, struct super_block *sb)
+LSM_HOOK(int, 0, quotactl, int cmds, int type, int id, const struct super_block *sb)
LSM_HOOK(int, 0, quota_on, struct dentry *dentry)
LSM_HOOK(int, 0, syslog, int type)
LSM_HOOK(int, 0, settime, const struct timespec64 *ts,
const struct timezone *tz)
LSM_HOOK(int, 0, vm_enough_memory, struct mm_struct *mm, long pages)
LSM_HOOK(int, 0, bprm_creds_for_exec, struct linux_binprm *bprm)
-LSM_HOOK(int, 0, bprm_creds_from_file, struct linux_binprm *bprm, struct file *file)
+LSM_HOOK(int, 0, bprm_creds_from_file, struct linux_binprm *bprm, const struct file *file)
LSM_HOOK(int, 0, bprm_check_security, struct linux_binprm *bprm)
-LSM_HOOK(void, LSM_RET_VOID, bprm_committing_creds, struct linux_binprm *bprm)
-LSM_HOOK(void, LSM_RET_VOID, bprm_committed_creds, struct linux_binprm *bprm)
+LSM_HOOK(void, LSM_RET_VOID, bprm_committing_creds, const struct linux_binprm *bprm)
+LSM_HOOK(void, LSM_RET_VOID, bprm_committed_creds, const struct linux_binprm *bprm)
LSM_HOOK(int, 0, fs_context_submount, struct fs_context *fc, struct super_block *reference)
LSM_HOOK(int, 0, fs_context_dup, struct fs_context *fc,
struct fs_context *src_sc)
@@ -66,7 +66,7 @@ LSM_HOOK(void, LSM_RET_VOID, sb_free_mnt_opts, void *mnt_opts)
LSM_HOOK(int, 0, sb_eat_lsm_opts, char *orig, void **mnt_opts)
LSM_HOOK(int, 0, sb_mnt_opts_compat, struct super_block *sb, void *mnt_opts)
LSM_HOOK(int, 0, sb_remount, struct super_block *sb, void *mnt_opts)
-LSM_HOOK(int, 0, sb_kern_mount, struct super_block *sb)
+LSM_HOOK(int, 0, sb_kern_mount, const struct super_block *sb)
LSM_HOOK(int, 0, sb_show_options, struct seq_file *m, struct super_block *sb)
LSM_HOOK(int, 0, sb_statfs, struct dentry *dentry)
LSM_HOOK(int, 0, sb_mount, const char *dev_name, const struct path *path,
diff --git a/include/linux/security.h b/include/linux/security.h
index 5f16eecde00b..1d1df326c881 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -151,7 +151,7 @@ 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_creds_from_file(struct linux_binprm *bprm, struct file *file);
+extern int cap_bprm_creds_from_file(struct linux_binprm *bprm, const struct file *file);
int cap_inode_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags);
int cap_inode_removexattr(struct mnt_idmap *idmap,
@@ -284,16 +284,16 @@ int security_capable(const struct cred *cred,
struct user_namespace *ns,
int cap,
unsigned int opts);
-int security_quotactl(int cmds, int type, int id, struct super_block *sb);
+int security_quotactl(int cmds, int type, int id, const struct super_block *sb);
int security_quota_on(struct dentry *dentry);
int security_syslog(int type);
int security_settime64(const struct timespec64 *ts, const struct timezone *tz);
int security_vm_enough_memory_mm(struct mm_struct *mm, long pages);
int security_bprm_creds_for_exec(struct linux_binprm *bprm);
-int security_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file);
+int security_bprm_creds_from_file(struct linux_binprm *bprm, const struct file *file);
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);
+void security_bprm_committing_creds(const struct linux_binprm *bprm);
+void security_bprm_committed_creds(const struct linux_binprm *bprm);
int security_fs_context_submount(struct fs_context *fc, struct super_block *reference);
int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc);
int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param);
@@ -304,7 +304,7 @@ void security_free_mnt_opts(void **mnt_opts);
int security_sb_eat_lsm_opts(char *options, void **mnt_opts);
int security_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts);
int security_sb_remount(struct super_block *sb, void *mnt_opts);
-int security_sb_kern_mount(struct super_block *sb);
+int security_sb_kern_mount(const struct super_block *sb);
int security_sb_show_options(struct seq_file *m, struct super_block *sb);
int security_sb_statfs(struct dentry *dentry);
int security_sb_mount(const char *dev_name, const struct path *path,
@@ -581,7 +581,7 @@ static inline int security_capable(const struct cred *cred,
}
static inline int security_quotactl(int cmds, int type, int id,
- struct super_block *sb)
+ const struct super_block *sb)
{
return 0;
}
@@ -613,7 +613,7 @@ static inline int security_bprm_creds_for_exec(struct linux_binprm *bprm)
}
static inline int security_bprm_creds_from_file(struct linux_binprm *bprm,
- struct file *file)
+ const struct file *file)
{
return cap_bprm_creds_from_file(bprm, file);
}
@@ -623,11 +623,11 @@ static inline int security_bprm_check(struct linux_binprm *bprm)
return 0;
}
-static inline void security_bprm_committing_creds(struct linux_binprm *bprm)
+static inline void security_bprm_committing_creds(const struct linux_binprm *bprm)
{
}
-static inline void security_bprm_committed_creds(struct linux_binprm *bprm)
+static inline void security_bprm_committed_creds(const struct linux_binprm *bprm)
{
}
diff --git a/kernel/cred.c b/kernel/cred.c
index 4dc0b27b5462..3c714cb31660 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -162,23 +162,29 @@ EXPORT_SYMBOL(__put_cred);
*/
void exit_creds(struct task_struct *tsk)
{
- struct cred *cred;
+ struct cred *real_cred, *cred;
kdebug("exit_creds(%u,%p,%p,{%d,%d})", tsk->pid, tsk->real_cred, tsk->cred,
atomic_read(&tsk->cred->usage),
read_cred_subscribers(tsk->cred));
- cred = (struct cred *) tsk->real_cred;
+ real_cred = (struct cred *) tsk->real_cred;
tsk->real_cred = NULL;
- validate_creds(cred);
- alter_cred_subscribers(cred, -1);
- put_cred(cred);
cred = (struct cred *) tsk->cred;
tsk->cred = NULL;
+
validate_creds(cred);
- alter_cred_subscribers(cred, -1);
- put_cred(cred);
+ if (real_cred == cred) {
+ alter_cred_subscribers(cred, -2);
+ put_cred_many(cred, 2);
+ } else {
+ validate_creds(real_cred);
+ alter_cred_subscribers(real_cred, -1);
+ put_cred(real_cred);
+ alter_cred_subscribers(cred, -1);
+ put_cred(cred);
+ }
#ifdef CONFIG_KEYS_REQUEST_CACHE
key_put(tsk->cached_requested_key);
@@ -355,8 +361,7 @@ 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);
+ p->real_cred = get_cred_many(p->cred, 2);
alter_cred_subscribers(p->cred, 2);
kdebug("share_creds(%p{%d,%d})",
p->cred, atomic_read(&p->cred->usage),
@@ -520,8 +525,7 @@ int commit_creds(struct cred *new)
proc_id_connector(task, PROC_EVENT_GID);
/* release the old obj and subj refs both */
- put_cred(old);
- put_cred(old);
+ put_cred_many(old, 2);
return 0;
}
EXPORT_SYMBOL(commit_creds);
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 108eccc5ada5..3fa325d5efac 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -734,7 +734,7 @@ fail:
* apparmor_bprm_committing_creds - do task cleanup on committing new creds
* @bprm: binprm for the exec (NOT NULL)
*/
-static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
+static void apparmor_bprm_committing_creds(const struct linux_binprm *bprm)
{
struct aa_label *label = aa_current_raw_label();
struct aa_label *new_label = cred_label(bprm->cred);
@@ -756,7 +756,7 @@ static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
* apparmor_bprm_committed_creds() - do cleanup after new creds committed
* @bprm: binprm for the exec (NOT NULL)
*/
-static void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
+static void apparmor_bprm_committed_creds(const struct linux_binprm *bprm)
{
/* clear out temporary/transitional state from the context */
aa_clear_task_ctx_trans(task_ctx(current));
diff --git a/security/commoncap.c b/security/commoncap.c
index bc0521104197..8e8c630ce204 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -720,7 +720,7 @@ int get_vfs_caps_from_disk(struct mnt_idmap *idmap,
* its xattrs and, if present, apply them to the proposed credentials being
* constructed by execve().
*/
-static int get_file_caps(struct linux_binprm *bprm, struct file *file,
+static int get_file_caps(struct linux_binprm *bprm, const struct file *file,
bool *effective, bool *has_fcap)
{
int rc = 0;
@@ -882,7 +882,7 @@ static inline bool nonroot_raised_pE(struct cred *new, const struct cred *old,
*
* Return: 0 if successful, -ve on error.
*/
-int cap_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file)
+int cap_bprm_creds_from_file(struct linux_binprm *bprm, const struct file *file)
{
/* Process setpcap binaries and capabilities for uid 0 */
const struct cred *old = current_cred();
diff --git a/security/security.c b/security/security.c
index 23b129d482a7..dcb3e7014f9b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -957,7 +957,7 @@ int security_capable(const struct cred *cred,
*
* Return: Returns 0 if permission is granted.
*/
-int security_quotactl(int cmds, int type, int id, struct super_block *sb)
+int security_quotactl(int cmds, int type, int id, const struct super_block *sb)
{
return call_int_hook(quotactl, 0, cmds, type, id, sb);
}
@@ -1079,7 +1079,7 @@ int security_bprm_creds_for_exec(struct linux_binprm *bprm)
*
* Return: Returns 0 if the hook is successful and permission is granted.
*/
-int security_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file)
+int security_bprm_creds_from_file(struct linux_binprm *bprm, const struct file *file)
{
return call_int_hook(bprm_creds_from_file, 0, bprm, file);
}
@@ -1118,7 +1118,7 @@ int security_bprm_check(struct linux_binprm *bprm)
* open file descriptors to which access will no longer be granted when the
* attributes are changed. This is called immediately before commit_creds().
*/
-void security_bprm_committing_creds(struct linux_binprm *bprm)
+void security_bprm_committing_creds(const struct linux_binprm *bprm)
{
call_void_hook(bprm_committing_creds, bprm);
}
@@ -1134,7 +1134,7 @@ void security_bprm_committing_creds(struct linux_binprm *bprm)
* process such as clearing out non-inheritable signal state. This is called
* immediately after commit_creds().
*/
-void security_bprm_committed_creds(struct linux_binprm *bprm)
+void security_bprm_committed_creds(const struct linux_binprm *bprm)
{
call_void_hook(bprm_committed_creds, bprm);
}
@@ -1319,7 +1319,7 @@ EXPORT_SYMBOL(security_sb_remount);
*
* Return: Returns 0 if permission is granted.
*/
-int security_sb_kern_mount(struct super_block *sb)
+int security_sb_kern_mount(const struct super_block *sb)
{
return call_int_hook(sb_kern_mount, 0, sb);
}
@@ -3957,7 +3957,7 @@ void security_inode_invalidate_secctx(struct inode *inode)
EXPORT_SYMBOL(security_inode_invalidate_secctx);
/**
- * security_inode_notifysecctx() - Nofify the LSM of an inode's security label
+ * security_inode_notifysecctx() - Notify the LSM of an inode's security label
* @inode: inode
* @ctx: secctx
* @ctxlen: length of secctx
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 2aa0e219d721..feda711c6b7b 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1937,7 +1937,7 @@ static inline int may_rename(struct inode *old_dir,
/* Check whether a task can perform a filesystem operation. */
static int superblock_has_perm(const struct cred *cred,
- struct super_block *sb,
+ const struct super_block *sb,
u32 perms,
struct common_audit_data *ad)
{
@@ -2139,7 +2139,7 @@ static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
return cred_has_capability(cred, cap, opts, ns == &init_user_ns);
}
-static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
+static int selinux_quotactl(int cmds, int type, int id, const struct super_block *sb)
{
const struct cred *cred = current_cred();
int rc = 0;
@@ -2455,7 +2455,7 @@ static inline void flush_unauthorized_files(const struct cred *cred,
/*
* Prepare a process for imminent new credential changes due to exec
*/
-static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
+static void selinux_bprm_committing_creds(const struct linux_binprm *bprm)
{
struct task_security_struct *new_tsec;
struct rlimit *rlim, *initrlim;
@@ -2501,7 +2501,7 @@ static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
* Clean up the process immediately after the installation of new credentials
* due to exec
*/
-static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
+static void selinux_bprm_committed_creds(const struct linux_binprm *bprm)
{
const struct task_security_struct *tsec = selinux_cred(current_cred());
u32 osid, sid;
@@ -2721,7 +2721,7 @@ out_bad_option:
return -EINVAL;
}
-static int selinux_sb_kern_mount(struct super_block *sb)
+static int selinux_sb_kern_mount(const struct super_block *sb)
{
const struct cred *cred = current_cred();
struct common_audit_data ad;
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index 25006fddc964..255f1b470295 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -52,7 +52,7 @@ static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
*
* @bprm: Pointer to "struct linux_binprm".
*/
-static void tomoyo_bprm_committed_creds(struct linux_binprm *bprm)
+static void tomoyo_bprm_committed_creds(const struct linux_binprm *bprm)
{
/* Clear old_domain_info saved by execve() request. */
struct tomoyo_task *s = tomoyo_task(current);