+/* Update inode info in audit rules based on filesystem event. */
+static void audit_update_watch(struct audit_parent *parent,
+ const char *dname, dev_t dev,
+ unsigned long ino, unsigned invalidating)
+{
+ struct audit_watch *owatch, *nwatch, *nextw;
+ struct audit_krule *r, *nextr;
+ struct audit_entry *oentry, *nentry;
+ struct audit_buffer *ab;
+
+ mutex_lock(&audit_filter_mutex);
+ list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
+ if (audit_compare_dname_path(dname, owatch->path, NULL))
+ continue;
+
+ /* If the update involves invalidating rules, do the inode-based
+ * filtering now, so we don't omit records. */
+ if (invalidating &&
+ audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
+ audit_set_auditable(current->audit_context);
+
+ nwatch = audit_dupe_watch(owatch);
+ if (unlikely(IS_ERR(nwatch))) {
+ mutex_unlock(&audit_filter_mutex);
+ audit_panic("error updating watch, skipping");
+ return;
+ }
+ nwatch->dev = dev;
+ nwatch->ino = ino;
+
+ list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
+
+ oentry = container_of(r, struct audit_entry, rule);
+ list_del(&oentry->rule.rlist);
+ list_del_rcu(&oentry->list);
+
+ nentry = audit_dupe_rule(&oentry->rule, nwatch);
+ if (unlikely(IS_ERR(nentry)))
+ audit_panic("error updating watch, removing");
+ else {
+ int h = audit_hash_ino((u32)ino);
+ list_add(&nentry->rule.rlist, &nwatch->rules);
+ list_add_rcu(&nentry->list, &audit_inode_hash[h]);
+ }
+
+ call_rcu(&oentry->rcu, audit_free_rule_rcu);
+ }
+
+ ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ audit_log_format(ab, "audit updated rules specifying watch=");
+ audit_log_untrustedstring(ab, owatch->path);
+ audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
+ audit_log_end(ab);
+
+ audit_remove_watch(owatch);
+ goto add_watch_to_parent; /* event applies to a single watch */
+ }
+ mutex_unlock(&audit_filter_mutex);
+ return;
+
+add_watch_to_parent:
+ list_add(&nwatch->wlist, &parent->watches);
+ mutex_unlock(&audit_filter_mutex);
+ return;
+}
+
+/* Remove all watches & rules associated with a parent that is going away. */
+static void audit_remove_parent_watches(struct audit_parent *parent)
+{
+ struct audit_watch *w, *nextw;
+ struct audit_krule *r, *nextr;
+ struct audit_entry *e;
+
+ mutex_lock(&audit_filter_mutex);
+ parent->flags |= AUDIT_PARENT_INVALID;
+ list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
+ list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
+ e = container_of(r, struct audit_entry, rule);
+ list_del(&r->rlist);
+ list_del_rcu(&e->list);
+ call_rcu(&e->rcu, audit_free_rule_rcu);
+
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit implicitly removed rule from list=%d\n",
+ AUDIT_FILTER_EXIT);
+ }
+ audit_remove_watch(w);
+ }
+ mutex_unlock(&audit_filter_mutex);
+}
+
+/* Unregister inotify watches for parents on in_list.
+ * Generates an IN_IGNORED event. */
+static void audit_inotify_unregister(struct list_head *in_list)
+{
+ struct audit_parent *p, *n;
+
+ list_for_each_entry_safe(p, n, in_list, ilist) {
+ list_del(&p->ilist);
+ inotify_rm_watch(audit_ih, &p->wdata);
+ /* the put matching the get in audit_do_del_rule() */
+ put_inotify_watch(&p->wdata);
+ }
+}
+
+/* Find an existing audit rule.
+ * Caller must hold audit_filter_mutex to prevent stale rule data. */
+static struct audit_entry *audit_find_rule(struct audit_entry *entry,
+ struct list_head *list)
+{
+ struct audit_entry *e, *found = NULL;
+ int h;
+
+ if (entry->rule.watch) {
+ /* we don't know the inode number, so must walk entire hash */
+ for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
+ list = &audit_inode_hash[h];
+ list_for_each_entry(e, list, list)
+ if (!audit_compare_rule(&entry->rule, &e->rule)) {
+ found = e;
+ goto out;
+ }
+ }
+ goto out;
+ }
+
+ list_for_each_entry(e, list, list)
+ if (!audit_compare_rule(&entry->rule, &e->rule)) {
+ found = e;
+ goto out;
+ }
+
+out:
+ return found;
+}
+
+/* Get path information necessary for adding watches. */
+static int audit_get_nd(char *path, struct nameidata **ndp,
+ struct nameidata **ndw)
+{
+ struct nameidata *ndparent, *ndwatch;
+ int err;
+
+ ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
+ if (unlikely(!ndparent))
+ return -ENOMEM;
+
+ ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
+ if (unlikely(!ndwatch)) {
+ kfree(ndparent);
+ return -ENOMEM;
+ }
+
+ err = path_lookup(path, LOOKUP_PARENT, ndparent);
+ if (err) {
+ kfree(ndparent);
+ kfree(ndwatch);
+ return err;
+ }
+
+ err = path_lookup(path, 0, ndwatch);
+ if (err) {
+ kfree(ndwatch);
+ ndwatch = NULL;
+ }
+
+ *ndp = ndparent;
+ *ndw = ndwatch;
+
+ return 0;
+}
+
+/* Release resources used for watch path information. */
+static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
+{
+ if (ndp) {
+ path_release(ndp);
+ kfree(ndp);
+ }
+ if (ndw) {
+ path_release(ndw);
+ kfree(ndw);
+ }
+}
+
+/* Associate the given rule with an existing parent inotify_watch.
+ * Caller must hold audit_filter_mutex. */
+static void audit_add_to_parent(struct audit_krule *krule,
+ struct audit_parent *parent)
+{
+ struct audit_watch *w, *watch = krule->watch;
+ int watch_found = 0;
+
+ list_for_each_entry(w, &parent->watches, wlist) {
+ if (strcmp(watch->path, w->path))
+ continue;
+
+ watch_found = 1;
+
+ /* put krule's and initial refs to temporary watch */
+ audit_put_watch(watch);
+ audit_put_watch(watch);
+
+ audit_get_watch(w);
+ krule->watch = watch = w;
+ break;
+ }
+
+ if (!watch_found) {
+ get_inotify_watch(&parent->wdata);
+ watch->parent = parent;
+
+ list_add(&watch->wlist, &parent->watches);
+ }
+ list_add(&krule->rlist, &watch->rules);
+}
+
+/* Find a matching watch entry, or add this one.
+ * Caller must hold audit_filter_mutex. */
+static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
+ struct nameidata *ndw)
+{
+ struct audit_watch *watch = krule->watch;
+ struct inotify_watch *i_watch;
+ struct audit_parent *parent;
+ int ret = 0;
+
+ /* update watch filter fields */
+ if (ndw) {
+ watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
+ watch->ino = ndw->dentry->d_inode->i_ino;
+ }
+
+ /* The audit_filter_mutex must not be held during inotify calls because
+ * we hold it during inotify event callback processing. If an existing
+ * inotify watch is found, inotify_find_watch() grabs a reference before
+ * returning.
+ */
+ mutex_unlock(&audit_filter_mutex);
+
+ if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
+ parent = audit_init_parent(ndp);
+ if (IS_ERR(parent)) {
+ /* caller expects mutex locked */
+ mutex_lock(&audit_filter_mutex);
+ return PTR_ERR(parent);
+ }
+ } else
+ parent = container_of(i_watch, struct audit_parent, wdata);
+
+ mutex_lock(&audit_filter_mutex);
+
+ /* parent was moved before we took audit_filter_mutex */
+ if (parent->flags & AUDIT_PARENT_INVALID)
+ ret = -ENOENT;
+ else
+ audit_add_to_parent(krule, parent);
+
+ /* match get in audit_init_parent or inotify_find_watch */
+ put_inotify_watch(&parent->wdata);
+ return ret;
+}
+
+/* Add rule to given filterlist if not a duplicate. */