security/keys/gc.c

14  * Delay between key revocation/expiry in seconds
34 #define KEY_GC_KEY_EXPIRED	0	/* A key expired and needs unlinking */
40  * Any key whose type gets unregistered will be re-typed to this if it can't be
70  * Set the expiration time on a key.
72 void key_set_expiry(struct key *key, time64_t expiry)
74 	key->expiry = expiry;
76 		if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
92  * Some key's cleanup time was met after it expired, so we need to get the
138 		struct key *key =
139 			list_entry(keys->next, struct key, graveyard_link);
140 		short state = key->state;
142 		list_del(&key->graveyard_link);
144 		kdebug("- %u", key->serial);
145 		key_check(key);
148 		remove_watch_list(key->watchers, key->serial);
149 		key->watchers = NULL;
152 		/* Throw away the key data if the key is instantiated */
153 		if (state == KEY_IS_POSITIVE && key->type->destroy)
154 			key->type->destroy(key);
156 		security_key_free(key);
158 		/* deal with the user's key tracking and quota */
159 		if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
160 			spin_lock(&key->user->lock);
161 			key->user->qnkeys--;
162 			key->user->qnbytes -= key->quotalen;
163 			spin_unlock(&key->user->lock);
166 		atomic_dec(&key->user->nkeys);
168 			atomic_dec(&key->user->nikeys);
170 		key_user_put(key->user);
171 		key_put_tag(key->domain_tag);
172 		kfree(key->description);
174 		memzero_explicit(key, sizeof(*key));
175 		kmem_cache_free(key_jar, key);
193 #define KEY_GC_REAPING_DEAD_2	0x20	/* - We need to reap dead key links */
195 #define KEY_GC_FOUND_DEAD_KEY	0x80	/* - We found at least one dead key */
198 	struct key *key;
217 	/* As only this function is permitted to remove things from the key
226 		key = rb_entry(cursor, struct key, serial_node);
229 		if (refcount_read(&key->usage) == 0)
233 			if (key->type == key_gc_dead_keytype) {
235 				set_bit(KEY_FLAG_DEAD, &key->flags);
236 				key->perm = 0;
238 			} else if (key->type == &key_type_keyring &&
239 				   key->restrict_link) {
244 		expiry = key->expiry;
246 			if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
250 				       key_serial(key), key->expiry - limit);
251 				new_timer = key->expiry;
256 			if (key->type == key_gc_dead_keytype)
261 			if (key->type == &key_type_keyring)
266 			if (key->type == key_gc_dead_keytype)
337 	/* We found an unreferenced key - once we've removed it from the tree,
341 	kdebug("unrefd key %d", key->serial);
342 	rb_erase(&key->serial_node, &key_serial_tree);
345 	list_add_tail(&key->graveyard_link, &graveyard);
350 	 * it is associated with the dead key type.
354 	keyring_restriction_gc(key, key_gc_dead_keytype);
364 	keyring_gc(key, limit);
367 	/* We found a dead key that is still referenced.  Reset its type and
372 	kdebug("destroy key %d", key->serial);
373 	down_write(&key->sem);
374 	key->type = &key_type_dead;
376 		key_gc_dead_keytype->destroy(key);
377 	memset(&key->payload, KEY_DESTROY, sizeof(key->payload));
378 	up_write(&key->sem);