diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/apparmor/apparmorfs.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index d6329aa7aa98..7a26608a5666 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -20,6 +20,7 @@ #include <linux/uaccess.h> #include <linux/namei.h> #include <linux/capability.h> +#include <linux/rcupdate.h> #include "include/apparmor.h" #include "include/apparmorfs.h" @@ -512,6 +513,240 @@ fail2: } +#define list_entry_next(pos, member) \ + list_entry(pos->member.next, typeof(*pos), member) +#define list_entry_is_head(pos, head, member) (&pos->member == (head)) + +/** + * __next_namespace - find the next namespace to list + * @root: root namespace to stop search at (NOT NULL) + * @ns: current ns position (NOT NULL) + * + * Find the next namespace from @ns under @root and handle all locking needed + * while switching current namespace. + * + * Returns: next namespace or NULL if at last namespace under @root + * Requires: ns->parent->lock to be held + * NOTE: will not unlock root->lock + */ +static struct aa_namespace *__next_namespace(struct aa_namespace *root, + struct aa_namespace *ns) +{ + struct aa_namespace *parent, *next; + + /* is next namespace a child */ + if (!list_empty(&ns->sub_ns)) { + next = list_first_entry(&ns->sub_ns, typeof(*ns), base.list); + mutex_lock(&next->lock); + return next; + } + + /* check if the next ns is a sibling, parent, gp, .. */ + parent = ns->parent; + while (parent) { + mutex_unlock(&ns->lock); + next = list_entry_next(ns, base.list); + if (!list_entry_is_head(next, &parent->sub_ns, base.list)) { + mutex_lock(&next->lock); + return next; + } + if (parent == root) + return NULL; + ns = parent; + parent = parent->parent; + } + + return NULL; +} + +/** + * __first_profile - find the first profile in a namespace + * @root: namespace that is root of profiles being displayed (NOT NULL) + * @ns: namespace to start in (NOT NULL) + * + * Returns: unrefcounted profile or NULL if no profile + * Requires: profile->ns.lock to be held + */ +static struct aa_profile *__first_profile(struct aa_namespace *root, + struct aa_namespace *ns) +{ + for (; ns; ns = __next_namespace(root, ns)) { + if (!list_empty(&ns->base.profiles)) + return list_first_entry(&ns->base.profiles, + struct aa_profile, base.list); + } + return NULL; +} + +/** + * __next_profile - step to the next profile in a profile tree + * @profile: current profile in tree (NOT NULL) + * + * Perform a depth first traversal on the profile tree in a namespace + * + * Returns: next profile or NULL if done + * Requires: profile->ns.lock to be held + */ +static struct aa_profile *__next_profile(struct aa_profile *p) +{ + struct aa_profile *parent; + struct aa_namespace *ns = p->ns; + + /* is next profile a child */ + if (!list_empty(&p->base.profiles)) + return list_first_entry(&p->base.profiles, typeof(*p), + base.list); + + /* is next profile a sibling, parent sibling, gp, sibling, .. */ + parent = rcu_dereference_protected(p->parent, + mutex_is_locked(&p->ns->lock)); + while (parent) { + p = list_entry_next(p, base.list); + if (!list_entry_is_head(p, &parent->base.profiles, base.list)) + return p; + p = parent; + parent = rcu_dereference_protected(parent->parent, + mutex_is_locked(&parent->ns->lock)); + } + + /* is next another profile in the namespace */ + p = list_entry_next(p, base.list); + if (!list_entry_is_head(p, &ns->base.profiles, base.list)) + return p; + + return NULL; +} + +/** + * next_profile - step to the next profile in where ever it may be + * @root: root namespace (NOT NULL) + * @profile: current profile (NOT NULL) + * + * Returns: next profile or NULL if there isn't one + */ +static struct aa_profile *next_profile(struct aa_namespace *root, + struct aa_profile *profile) +{ + struct aa_profile *next = __next_profile(profile); + if (next) + return next; + + /* finished all profiles in namespace move to next namespace */ + return __first_profile(root, __next_namespace(root, profile->ns)); +} + +/** + * p_start - start a depth first traversal of profile tree + * @f: seq_file to fill + * @pos: current position + * + * Returns: first profile under current namespace or NULL if none found + * + * acquires first ns->lock + */ +static void *p_start(struct seq_file *f, loff_t *pos) +{ + struct aa_profile *profile = NULL; + struct aa_namespace *root = aa_current_profile()->ns; + loff_t l = *pos; + f->private = aa_get_namespace(root); + + + /* find the first profile */ + mutex_lock(&root->lock); + profile = __first_profile(root, root); + + /* skip to position */ + for (; profile && l > 0; l--) + profile = next_profile(root, profile); + + return profile; +} + +/** + * p_next - read the next profile entry + * @f: seq_file to fill + * @p: profile previously returned + * @pos: current position + * + * Returns: next profile after @p or NULL if none + * + * may acquire/release locks in namespace tree as necessary + */ +static void *p_next(struct seq_file *f, void *p, loff_t *pos) +{ + struct aa_profile *profile = p; + struct aa_namespace *ns = f->private; + (*pos)++; + + return next_profile(ns, profile); +} + +/** + * p_stop - stop depth first traversal + * @f: seq_file we are filling + * @p: the last profile writen + * + * Release all locking done by p_start/p_next on namespace tree + */ +static void p_stop(struct seq_file *f, void *p) +{ + struct aa_profile *profile = p; + struct aa_namespace *root = f->private, *ns; + + if (profile) { + for (ns = profile->ns; ns && ns != root; ns = ns->parent) + mutex_unlock(&ns->lock); + } + mutex_unlock(&root->lock); + aa_put_namespace(root); +} + +/** + * seq_show_profile - show a profile entry + * @f: seq_file to file + * @p: current position (profile) (NOT NULL) + * + * Returns: error on failure + */ +static int seq_show_profile(struct seq_file *f, void *p) +{ + struct aa_profile *profile = (struct aa_profile *)p; + struct aa_namespace *root = f->private; + + if (profile->ns != root) + seq_printf(f, ":%s://", aa_ns_name(root, profile->ns)); + seq_printf(f, "%s (%s)\n", profile->base.hname, + aa_profile_mode_names[profile->mode]); + + return 0; +} + +static const struct seq_operations aa_fs_profiles_op = { + .start = p_start, + .next = p_next, + .stop = p_stop, + .show = seq_show_profile, +}; + +static int profiles_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &aa_fs_profiles_op); +} + +static int profiles_release(struct inode *inode, struct file *file) +{ + return seq_release(inode, file); +} + +static const struct file_operations aa_fs_profiles_fops = { + .open = profiles_open, + .read = seq_read, + .llseek = seq_lseek, + .release = profiles_release, +}; + + /** Base file system setup **/ static struct aa_fs_entry aa_fs_entry_file[] = { AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \ @@ -545,6 +780,7 @@ static struct aa_fs_entry aa_fs_entry_apparmor[] = { AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load), AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace), AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove), + AA_FS_FILE_FOPS("profiles", 0640, &aa_fs_profiles_fops), AA_FS_DIR("features", aa_fs_entry_features), { } }; |