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author | Al Viro <viro@zeniv.linux.org.uk> | 2009-06-24 00:02:38 -0400 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2009-06-24 00:02:38 -0400 |
commit | 916d75761c971b6e630a26bd4ba472e90ac9a4b9 (patch) | |
tree | 3a4b18d0d29c1d12f64fefbb2bc5559813a686f7 /kernel/audit_tree.c | |
parent | 9d9609851003ebed15957f0f2ce18492739ee124 (diff) | |
download | kernel_goldelico_gta04-916d75761c971b6e630a26bd4ba472e90ac9a4b9.zip kernel_goldelico_gta04-916d75761c971b6e630a26bd4ba472e90ac9a4b9.tar.gz kernel_goldelico_gta04-916d75761c971b6e630a26bd4ba472e90ac9a4b9.tar.bz2 |
Fix rule eviction order for AUDIT_DIR
If syscall removes the root of subtree being watched, we
definitely do not want the rules refering that subtree
to be destroyed without the syscall in question having
a chance to match them.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'kernel/audit_tree.c')
-rw-r--r-- | kernel/audit_tree.c | 56 |
1 files changed, 51 insertions, 5 deletions
diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c index 3ff0731..2451dc6 100644 --- a/kernel/audit_tree.c +++ b/kernel/audit_tree.c @@ -2,6 +2,7 @@ #include <linux/inotify.h> #include <linux/namei.h> #include <linux/mount.h> +#include <linux/kthread.h> struct audit_tree; struct audit_chunk; @@ -517,6 +518,8 @@ static void trim_marked(struct audit_tree *tree) } } +static void audit_schedule_prune(void); + /* called with audit_filter_mutex */ int audit_remove_tree_rule(struct audit_krule *rule) { @@ -822,10 +825,11 @@ int audit_tag_tree(char *old, char *new) /* * That gets run when evict_chunk() ends up needing to kill audit_tree. - * Runs from a separate thread, with audit_cmd_mutex held. + * Runs from a separate thread. */ -void audit_prune_trees(void) +static int prune_tree_thread(void *unused) { + mutex_lock(&audit_cmd_mutex); mutex_lock(&audit_filter_mutex); while (!list_empty(&prune_list)) { @@ -842,6 +846,40 @@ void audit_prune_trees(void) } mutex_unlock(&audit_filter_mutex); + mutex_unlock(&audit_cmd_mutex); + return 0; +} + +static void audit_schedule_prune(void) +{ + kthread_run(prune_tree_thread, NULL, "audit_prune_tree"); +} + +/* + * ... and that one is done if evict_chunk() decides to delay until the end + * of syscall. Runs synchronously. + */ +void audit_kill_trees(struct list_head *list) +{ + mutex_lock(&audit_cmd_mutex); + mutex_lock(&audit_filter_mutex); + + while (!list_empty(list)) { + struct audit_tree *victim; + + victim = list_entry(list->next, struct audit_tree, list); + kill_rules(victim); + list_del_init(&victim->list); + + mutex_unlock(&audit_filter_mutex); + + prune_one(victim); + + mutex_lock(&audit_filter_mutex); + } + + mutex_unlock(&audit_filter_mutex); + mutex_unlock(&audit_cmd_mutex); } /* @@ -852,6 +890,8 @@ void audit_prune_trees(void) static void evict_chunk(struct audit_chunk *chunk) { struct audit_tree *owner; + struct list_head *postponed = audit_killed_trees(); + int need_prune = 0; int n; if (chunk->dead) @@ -867,15 +907,21 @@ static void evict_chunk(struct audit_chunk *chunk) owner->root = NULL; list_del_init(&owner->same_root); spin_unlock(&hash_lock); - kill_rules(owner); - list_move(&owner->list, &prune_list); - audit_schedule_prune(); + if (!postponed) { + kill_rules(owner); + list_move(&owner->list, &prune_list); + need_prune = 1; + } else { + list_move(&owner->list, postponed); + } spin_lock(&hash_lock); } list_del_rcu(&chunk->hash); for (n = 0; n < chunk->count; n++) list_del_init(&chunk->owners[n].list); spin_unlock(&hash_lock); + if (need_prune) + audit_schedule_prune(); mutex_unlock(&audit_filter_mutex); } |