+/* Duplicate the given audit watch. The new watch's rules list is initialized
+ * to an empty list and wlist is undefined. */
+static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
+{
+ char *path;
+ struct audit_watch *new;
+
+ path = kstrdup(old->path, GFP_KERNEL);
+ if (unlikely(!path))
+ return ERR_PTR(-ENOMEM);
+
+ new = audit_init_watch(path);
+ if (IS_ERR(new)) {
+ kfree(path);
+ goto out;
+ }
+
+ new->dev = old->dev;
+ new->ino = old->ino;
+ get_inotify_watch(&old->parent->wdata);
+ new->parent = old->parent;
+
+out:
+ return new;
+}
+
+/* Duplicate LSM field information. The lsm_rule is opaque, so must be
+ * re-initialized. */
+static inline int audit_dupe_lsm_field(struct audit_field *df,
+ struct audit_field *sf)
+{
+ int ret = 0;
+ char *lsm_str;
+
+ /* our own copy of lsm_str */
+ lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
+ if (unlikely(!lsm_str))
+ return -ENOMEM;
+ df->lsm_str = lsm_str;
+
+ /* our own (refreshed) copy of lsm_rule */
+ ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
+ (void **)&df->lsm_rule);
+ /* Keep currently invalid fields around in case they
+ * become valid after a policy reload. */
+ if (ret == -EINVAL) {
+ printk(KERN_WARNING "audit rule for LSM \'%s\' is "
+ "invalid\n", df->lsm_str);
+ ret = 0;
+ }
+
+ return ret;
+}
+
+/* Duplicate an audit rule. This will be a deep copy with the exception
+ * of the watch - that pointer is carried over. The LSM specific fields
+ * will be updated in the copy. The point is to be able to replace the old
+ * rule with the new rule in the filterlist, then free the old rule.
+ * The rlist element is undefined; list manipulations are handled apart from
+ * the initial copy. */
+static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
+ struct audit_watch *watch)
+{
+ u32 fcount = old->field_count;
+ struct audit_entry *entry;
+ struct audit_krule *new;
+ char *fk;
+ int i, err = 0;
+
+ entry = audit_init_entry(fcount);
+ if (unlikely(!entry))
+ return ERR_PTR(-ENOMEM);
+
+ new = &entry->rule;
+ new->vers_ops = old->vers_ops;
+ new->flags = old->flags;
+ new->listnr = old->listnr;
+ new->action = old->action;
+ for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
+ new->mask[i] = old->mask[i];
+ new->prio = old->prio;
+ new->buflen = old->buflen;
+ new->inode_f = old->inode_f;
+ new->watch = NULL;
+ new->field_count = old->field_count;
+ /*
+ * note that we are OK with not refcounting here; audit_match_tree()
+ * never dereferences tree and we can't get false positives there
+ * since we'd have to have rule gone from the list *and* removed
+ * before the chunks found by lookup had been allocated, i.e. before
+ * the beginning of list scan.
+ */
+ new->tree = old->tree;
+ memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
+
+ /* deep copy this information, updating the lsm_rule fields, because
+ * the originals will all be freed when the old rule is freed. */
+ for (i = 0; i < fcount; i++) {
+ switch (new->fields[i].type) {
+ case AUDIT_SUBJ_USER:
+ case AUDIT_SUBJ_ROLE:
+ case AUDIT_SUBJ_TYPE:
+ case AUDIT_SUBJ_SEN:
+ case AUDIT_SUBJ_CLR:
+ case AUDIT_OBJ_USER:
+ case AUDIT_OBJ_ROLE:
+ case AUDIT_OBJ_TYPE:
+ case AUDIT_OBJ_LEV_LOW:
+ case AUDIT_OBJ_LEV_HIGH:
+ err = audit_dupe_lsm_field(&new->fields[i],
+ &old->fields[i]);
+ break;
+ case AUDIT_FILTERKEY:
+ fk = kstrdup(old->filterkey, GFP_KERNEL);
+ if (unlikely(!fk))
+ err = -ENOMEM;
+ else
+ new->filterkey = fk;
+ }
+ if (err) {
+ audit_free_rule(entry);
+ return ERR_PTR(err);
+ }
+ }
+
+ if (watch) {
+ audit_get_watch(watch);
+ new->watch = watch;
+ }
+
+ return entry;
+}
+
+/* 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;
+
+ 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 && current->audit_context)
+ audit_filter_inodes(current, current->audit_context);
+
+ nwatch = audit_dupe_watch(owatch);
+ if (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 (IS_ERR(nentry)) {
+ list_del(&oentry->rule.list);
+ 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]);
+ list_replace(&oentry->rule.list,
+ &nentry->rule.list);
+ }
+
+ call_rcu(&oentry->rcu, audit_free_rule_rcu);
+ }
+
+ if (audit_enabled) {
+ struct audit_buffer *ab;
+ ab = audit_log_start(NULL, GFP_KERNEL,
+ AUDIT_CONFIG_CHANGE);
+ audit_log_format(ab, "auid=%u ses=%u",
+ audit_get_loginuid(current),
+ audit_get_sessionid(current));
+ audit_log_format(ab,
+ " op=updated rules specifying path=");
+ audit_log_untrustedstring(ab, owatch->path);
+ audit_log_format(ab, " with dev=%u ino=%lu\n",
+ dev, ino);
+ audit_log_format(ab, " list=%d res=1", r->listnr);
+ 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);
+ if (audit_enabled) {
+ struct audit_buffer *ab;
+ ab = audit_log_start(NULL, GFP_KERNEL,
+ AUDIT_CONFIG_CHANGE);
+ audit_log_format(ab, "auid=%u ses=%u",
+ audit_get_loginuid(current),
+ audit_get_sessionid(current));
+ audit_log_format(ab, " op=remove rule path=");
+ audit_log_untrustedstring(ab, w->path);
+ if (r->filterkey) {
+ audit_log_format(ab, " key=");
+ audit_log_untrustedstring(ab,
+ r->filterkey);
+ } else
+ audit_log_format(ab, " key=(null)");
+ audit_log_format(ab, " list=%d res=1",
+ r->listnr);
+ audit_log_end(ab);
+ }
+ list_del(&r->rlist);
+ list_del(&r->list);
+ list_del_rcu(&e->list);
+ call_rcu(&e->rcu, audit_free_rule_rcu);
+ }
+ 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 unpin matching the pin in audit_do_del_rule() */
+ unpin_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 **p)
+{
+ struct audit_entry *e, *found = NULL;
+ struct list_head *list;
+ int h;
+
+ if (entry->rule.inode_f) {
+ h = audit_hash_ino(entry->rule.inode_f->val);
+ *p = list = &audit_inode_hash[h];
+ } else 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;
+ } else {
+ *p = list = &audit_filter_list[entry->rule.listnr];
+ }
+
+ 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_put(&ndp->path);
+ kfree(ndp);
+ }
+ if (ndw) {
+ path_put(&ndw->path);
+ 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->path.dentry->d_inode->i_sb->s_dev;
+ watch->ino = ndw->path.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->path.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;
+}
+
+static u64 prio_low = ~0ULL/2;
+static u64 prio_high = ~0ULL/2 - 1;
+
+/* Add rule to given filterlist if not a duplicate. */
+static inline int audit_add_rule(struct audit_entry *entry)