2 /* Key garbage collector
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)  in key_set_expiry()  argument
74 	key->expiry = expiry;  in key_set_expiry()
76 		if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))  in key_set_expiry()
92  * Some key's cleanup time was met after it expired, so we need to get the
138 		struct key *key =  in key_gc_unused_keys()  local
139 			list_entry(keys->next, struct key, graveyard_link);  in key_gc_unused_keys()
140 		short state = key->state;  in key_gc_unused_keys()
142 		list_del(&key->graveyard_link);  in key_gc_unused_keys()
144 		kdebug("- %u", key->serial);  in key_gc_unused_keys()
145 		key_check(key);  in key_gc_unused_keys()
148 		remove_watch_list(key->watchers, key->serial);  in key_gc_unused_keys()
149 		key->watchers = NULL;  in key_gc_unused_keys()
152 		/* Throw away the key data if the key is instantiated */  in key_gc_unused_keys()
153 		if (state == KEY_IS_POSITIVE && key->type->destroy)  in key_gc_unused_keys()
154 			key->type->destroy(key);  in key_gc_unused_keys()
156 		security_key_free(key);  in key_gc_unused_keys()
158 		atomic_dec(&key->user->nkeys);  in key_gc_unused_keys()
160 			atomic_dec(&key->user->nikeys);  in key_gc_unused_keys()
162 		key_user_put(key->user);  in key_gc_unused_keys()
163 		key_put_tag(key->domain_tag);  in key_gc_unused_keys()
164 		kfree(key->description);  in key_gc_unused_keys()
166 		memzero_explicit(key, sizeof(*key));  in key_gc_unused_keys()
167 		kmem_cache_free(key_jar, key);  in key_gc_unused_keys()
185 #define KEY_GC_REAPING_DEAD_2	0x20	/* - We need to reap dead key links */  in key_garbage_collector()
187 #define KEY_GC_FOUND_DEAD_KEY	0x80	/* - We found at least one dead key */  in key_garbage_collector()
190 	struct key *key;  in key_garbage_collector()  local
209 	/* As only this function is permitted to remove things from the key  in key_garbage_collector()
218 		key = rb_entry(cursor, struct key, serial_node);  in key_garbage_collector()
221 		if (test_bit(KEY_FLAG_FINAL_PUT, &key->flags)) {  in key_garbage_collector()
222 			smp_mb(); /* Clobber key->user after FINAL_PUT seen. */  in key_garbage_collector()
227 			if (key->type == key_gc_dead_keytype) {  in key_garbage_collector()
229 				set_bit(KEY_FLAG_DEAD, &key->flags);  in key_garbage_collector()
230 				key->perm = 0;  in key_garbage_collector()
232 			} else if (key->type == &key_type_keyring &&  in key_garbage_collector()
233 				   key->restrict_link) {  in key_garbage_collector()
238 		expiry = key->expiry;  in key_garbage_collector()
240 			if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))  in key_garbage_collector()
244 				       key_serial(key), key->expiry - limit);  in key_garbage_collector()
245 				new_timer = key->expiry;  in key_garbage_collector()
250 			if (key->type == key_gc_dead_keytype)  in key_garbage_collector()
255 			if (key->type == &key_type_keyring)  in key_garbage_collector()
260 			if (key->type == key_gc_dead_keytype)  in key_garbage_collector()
331 	/* We found an unreferenced key - once we've removed it from the tree,  in key_garbage_collector()
335 	kdebug("unrefd key %d", key->serial);  in key_garbage_collector()
336 	rb_erase(&key->serial_node, &key_serial_tree);  in key_garbage_collector()
339 	list_add_tail(&key->graveyard_link, &graveyard);  in key_garbage_collector()
344 	 * it is associated with the dead key type.  in key_garbage_collector()
348 	keyring_restriction_gc(key, key_gc_dead_keytype);  in key_garbage_collector()
358 	keyring_gc(key, limit);  in key_garbage_collector()
361 	/* We found a dead key that is still referenced.  Reset its type and  in key_garbage_collector()
366 	kdebug("destroy key %d", key->serial);  in key_garbage_collector()
367 	down_write(&key->sem);  in key_garbage_collector()
368 	key->type = &key_type_dead;  in key_garbage_collector()
370 		key_gc_dead_keytype->destroy(key);  in key_garbage_collector()
371 	memset(&key->payload, KEY_DESTROY, sizeof(key->payload));  in key_garbage_collector()
372 	up_write(&key->sem);  in key_garbage_collector()