1 // SPDX-License-Identifier: GPL-2.0-or-later
4  * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved.
20 struct rb_root		key_serial_tree; /* tree of keys indexed by serial */
41 	       key, key->magic, KEY_DEBUG_MAGIC);  in __key_check()
65 		if (uid_lt(uid, user->uid))  in key_user_lookup()
66 			p = &(*p)->rb_left;  in key_user_lookup()
67 		else if (uid_gt(uid, user->uid))  in key_user_lookup()
68 			p = &(*p)->rb_right;  in key_user_lookup()
91 	 * second pass - so we use the candidate record */  in key_user_lookup()
92 	refcount_set(&candidate->usage, 1);  in key_user_lookup()
93 	atomic_set(&candidate->nkeys, 0);  in key_user_lookup()
94 	atomic_set(&candidate->nikeys, 0);  in key_user_lookup()
95 	candidate->uid = uid;  in key_user_lookup()
96 	candidate->qnkeys = 0;  in key_user_lookup()
97 	candidate->qnbytes = 0;  in key_user_lookup()
98 	spin_lock_init(&candidate->lock);  in key_user_lookup()
99 	mutex_init(&candidate->cons_lock);  in key_user_lookup()
101 	rb_link_node(&candidate->node, parent, p);  in key_user_lookup()
102 	rb_insert_color(&candidate->node, &key_user_tree);  in key_user_lookup()
107 	/* okay - we found a user record for this UID */  in key_user_lookup()
109 	refcount_inc(&user->usage);  in key_user_lookup()
121 	if (refcount_dec_and_lock(&user->usage, &key_user_lock)) {  in key_user_put()
122 		rb_erase(&user->node, &key_user_tree);  in key_user_put()
130  * Allocate a serial number for a key.  These are assigned randomly to avoid
138 	/* propose a random serial number and look for a hole for it in the  in key_alloc_serial()
139 	 * serial number tree */  in key_alloc_serial()
141 		get_random_bytes(&key->serial, sizeof(key->serial));  in key_alloc_serial()
143 		key->serial >>= 1; /* negative numbers are not permitted */  in key_alloc_serial()
144 	} while (key->serial < 3);  in key_alloc_serial()
156 		if (key->serial < xkey->serial)  in key_alloc_serial()
157 			p = &(*p)->rb_left;  in key_alloc_serial()
158 		else if (key->serial > xkey->serial)  in key_alloc_serial()
159 			p = &(*p)->rb_right;  in key_alloc_serial()
164 	/* we've found a suitable hole - arrange for this key to occupy it */  in key_alloc_serial()
165 	rb_link_node(&key->serial_node, parent, p);  in key_alloc_serial()
166 	rb_insert_color(&key->serial_node, &key_serial_tree);  in key_alloc_serial()
171 	/* we found a key with the proposed serial number - walk the tree from  in key_alloc_serial()
172 	 * that point looking for the next unused serial number */  in key_alloc_serial()
175 		key->serial++;  in key_alloc_serial()
176 		if (key->serial < 3) {  in key_alloc_serial()
177 			key->serial = 3;  in key_alloc_serial()
186 		if (key->serial < xkey->serial)  in key_alloc_serial()
192  * key_alloc - Allocate a key of the specified type.
203  * returned in an uninstantiated state and the caller needs to instantiate the
212  * quota is available, -EDQUOT will be returned.
215  * -EACCES will be returned.
235 	key = ERR_PTR(-EINVAL);  in key_alloc()
239 	if (type->vet_description) {  in key_alloc()
240 		ret = type->vet_description(desc);  in key_alloc()
248 	quotalen = desclen + 1 + type->def_datalen;  in key_alloc()
263 		spin_lock_irqsave(&user->lock, irqflags);  in key_alloc()
265 			if (user->qnkeys + 1 > maxkeys ||  in key_alloc()
266 			    user->qnbytes + quotalen > maxbytes ||  in key_alloc()
267 			    user->qnbytes + quotalen < user->qnbytes)  in key_alloc()
271 		user->qnkeys++;  in key_alloc()
272 		user->qnbytes += quotalen;  in key_alloc()
273 		spin_unlock_irqrestore(&user->lock, irqflags);  in key_alloc()
281 	key->index_key.desc_len = desclen;  in key_alloc()
282 	key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL);  in key_alloc()
283 	if (!key->index_key.description)  in key_alloc()
285 	key->index_key.type = type;  in key_alloc()
286 	key_set_index_key(&key->index_key);  in key_alloc()
288 	refcount_set(&key->usage, 1);  in key_alloc()
289 	init_rwsem(&key->sem);  in key_alloc()
290 	lockdep_set_class(&key->sem, &type->lock_class);  in key_alloc()
291 	key->user = user;  in key_alloc()
292 	key->quotalen = quotalen;  in key_alloc()
293 	key->datalen = type->def_datalen;  in key_alloc()
294 	key->uid = uid;  in key_alloc()
295 	key->gid = gid;  in key_alloc()
296 	key->perm = perm;  in key_alloc()
297 	key->expiry = TIME64_MAX;  in key_alloc()
298 	key->restrict_link = restrict_link;  in key_alloc()
299 	key->last_used_at = ktime_get_real_seconds();  in key_alloc()
302 		key->flags |= 1 << KEY_FLAG_IN_QUOTA;  in key_alloc()
304 		key->flags |= 1 << KEY_FLAG_BUILTIN;  in key_alloc()
306 		key->flags |= 1 << KEY_FLAG_UID_KEYRING;  in key_alloc()
308 		key->flags |= 1 << KEY_FLAG_KEEP;  in key_alloc()
311 	key->magic = KEY_DEBUG_MAGIC;  in key_alloc()
319 	/* publish the key by giving it a serial number */  in key_alloc()
320 	refcount_inc(&key->domain_tag->usage);  in key_alloc()
321 	atomic_inc(&user->nkeys);  in key_alloc()
328 	kfree(key->description);  in key_alloc()
331 		spin_lock_irqsave(&user->lock, irqflags);  in key_alloc()
332 		user->qnkeys--;  in key_alloc()
333 		user->qnbytes -= quotalen;  in key_alloc()
334 		spin_unlock_irqrestore(&user->lock, irqflags);  in key_alloc()
344 		spin_lock_irqsave(&user->lock, irqflags);  in key_alloc()
345 		user->qnkeys--;  in key_alloc()
346 		user->qnbytes -= quotalen;  in key_alloc()
347 		spin_unlock_irqrestore(&user->lock, irqflags);  in key_alloc()
351 	key = ERR_PTR(-ENOMEM);  in key_alloc()
355 	spin_unlock_irqrestore(&user->lock, irqflags);  in key_alloc()
357 	key = ERR_PTR(-EDQUOT);  in key_alloc()
363  * key_payload_reserve - Adjust data quota reservation for the key's payload
368  * If the amount is increased, then -EDQUOT may be returned if there isn't
375 	int delta = (int)datalen - key->datalen;  in key_payload_reserve()
381 	if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {  in key_payload_reserve()
382 		unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ?  in key_payload_reserve()
386 		spin_lock_irqsave(&key->user->lock, flags);  in key_payload_reserve()
389 		    (key->user->qnbytes + delta > maxbytes ||  in key_payload_reserve()
390 		     key->user->qnbytes + delta < key->user->qnbytes)) {  in key_payload_reserve()
391 			ret = -EDQUOT;  in key_payload_reserve()
394 			key->user->qnbytes += delta;  in key_payload_reserve()
395 			key->quotalen += delta;  in key_payload_reserve()
397 		spin_unlock_irqrestore(&key->user->lock, flags);  in key_payload_reserve()
402 		key->datalen = datalen;  in key_payload_reserve()
409  * Change the key state to being instantiated.
413 	/* Commit the payload before setting the state; barrier versus  in mark_key_instantiated()
416 	smp_store_release(&key->state,  in mark_key_instantiated()
438 	ret = -EBUSY;  in __key_instantiate_and_link()
443 	if (key->state == KEY_IS_UNINSTANTIATED) {  in __key_instantiate_and_link()
445 		ret = key->type->instantiate(key, prep);  in __key_instantiate_and_link()
449 			atomic_inc(&key->user->nikeys);  in __key_instantiate_and_link()
453 			if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))  in __key_instantiate_and_link()
458 				if (test_bit(KEY_FLAG_KEEP, &keyring->flags))  in __key_instantiate_and_link()
459 					set_bit(KEY_FLAG_KEEP, &key->flags);  in __key_instantiate_and_link()
468 			if (prep->expiry != TIME64_MAX)  in __key_instantiate_and_link()
469 				key_set_expiry(key, prep->expiry);  in __key_instantiate_and_link()
477 		wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);  in __key_instantiate_and_link()
483  * key_instantiate_and_link - Instantiate a key and link it into the keyring.
490  * Instantiate a key that's in the uninstantiated state using the provided data
496  * -EBUSY will be returned.
509 	prep.orig_description = key->description;  in key_instantiate_and_link()
512 	prep.quotalen = key->type->def_datalen;  in key_instantiate_and_link()
514 	if (key->type->preparse) {  in key_instantiate_and_link()
515 		ret = key->type->preparse(&prep);  in key_instantiate_and_link()
521 		ret = __key_link_lock(keyring, &key->index_key);  in key_instantiate_and_link()
525 		ret = __key_link_begin(keyring, &key->index_key, &edit);  in key_instantiate_and_link()
529 		if (keyring->restrict_link && keyring->restrict_link->check) {  in key_instantiate_and_link()
530 			struct key_restriction *keyres = keyring->restrict_link;  in key_instantiate_and_link()
532 			ret = keyres->check(keyring, key->type, &prep.payload,  in key_instantiate_and_link()
533 					    keyres->key);  in key_instantiate_and_link()
543 		__key_link_end(keyring, &key->index_key, edit);  in key_instantiate_and_link()
546 	if (key->type->preparse)  in key_instantiate_and_link()
547 		key->type->free_preparse(&prep);  in key_instantiate_and_link()
554  * key_reject_and_link - Negatively instantiate a key and link it into the keyring.
561  * Negatively instantiate a key that's in the uninstantiated state and, if
572  * -EBUSY will be returned.
587 	ret = -EBUSY;  in key_reject_and_link()
590 		if (keyring->restrict_link)  in key_reject_and_link()
591 			return -EPERM;  in key_reject_and_link()
593 		link_ret = __key_link_lock(keyring, &key->index_key);  in key_reject_and_link()
595 			link_ret = __key_link_begin(keyring, &key->index_key, &edit);  in key_reject_and_link()
597 				__key_link_end(keyring, &key->index_key, edit);  in key_reject_and_link()
604 	if (key->state == KEY_IS_UNINSTANTIATED) {  in key_reject_and_link()
606 		atomic_inc(&key->user->nikeys);  in key_reject_and_link()
607 		mark_key_instantiated(key, -error);  in key_reject_and_link()
608 		notify_key(key, NOTIFY_KEY_INSTANTIATED, -error);  in key_reject_and_link()
611 		if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))  in key_reject_and_link()
628 		__key_link_end(keyring, &key->index_key, edit);  in key_reject_and_link()
632 		wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);  in key_reject_and_link()
639  * key_put - Discard a reference to a key.
651 		if (refcount_dec_and_test(&key->usage)) {  in key_put()
655 			if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {  in key_put()
656 				spin_lock_irqsave(&key->user->lock, flags);  in key_put()
657 				key->user->qnkeys--;  in key_put()
658 				key->user->qnbytes -= key->quotalen;  in key_put()
659 				spin_unlock_irqrestore(&key->user->lock, flags);  in key_put()
668  * Find a key by its serial number.
682 		if (id < key->serial)  in key_lookup()
683 			n = n->rb_left;  in key_lookup()
684 		else if (id > key->serial)  in key_lookup()
685 			n = n->rb_right;  in key_lookup()
691 	key = ERR_PTR(-ENOKEY);  in key_lookup()
696 	 * reference to it - otherwise it's awaiting the gc.  in key_lookup()
698 	if (!refcount_inc_not_zero(&key->usage))  in key_lookup()
710  * We return with the sem read-locked if successful.  If the type wasn't
711  * available -ENOKEY is returned instead.
722 		if (strcmp(ktype->name, type) == 0)  in key_type_lookup()
727 	ktype = ERR_PTR(-ENOKEY);  in key_type_lookup()
738 	down_write(&key->sem);  in key_set_timeout()
744 	up_write(&key->sem);  in key_set_timeout()
773 	ret = -EEXIST;  in __key_update()
774 	if (!key->type->update)  in __key_update()
777 	down_write(&key->sem);  in __key_update()
779 	ret = key->type->update(key, prep);  in __key_update()
786 	up_write(&key->sem);  in __key_update()
827 		key_ref = ERR_PTR(-ENODEV);  in __key_create_or_update()
831 	key_ref = ERR_PTR(-EINVAL);  in __key_create_or_update()
832 	if (!index_key.type->instantiate ||  in __key_create_or_update()
833 	    (!index_key.description && !index_key.type->preparse))  in __key_create_or_update()
841 		restrict_link = keyring->restrict_link;  in __key_create_or_update()
843 	key_ref = ERR_PTR(-ENOTDIR);  in __key_create_or_update()
844 	if (keyring->type != &key_type_keyring)  in __key_create_or_update()
851 	prep.quotalen = index_key.type->def_datalen;  in __key_create_or_update()
853 	if (index_key.type->preparse) {  in __key_create_or_update()
854 		ret = index_key.type->preparse(&prep);  in __key_create_or_update()
861 		key_ref = ERR_PTR(-EINVAL);  in __key_create_or_update()
880 	if (restrict_link && restrict_link->check) {  in __key_create_or_update()
881 		ret = restrict_link->check(keyring, index_key.type,  in __key_create_or_update()
882 					   &prep.payload, restrict_link->key);  in __key_create_or_update()
902 		if (index_key.type->update) {  in __key_create_or_update()
911 			key_ref = ERR_PTR(-EEXIST);  in __key_create_or_update()
921 		if (index_key.type->read)  in __key_create_or_update()
925 		    index_key.type->update)  in __key_create_or_update()
931 			cred->fsuid, cred->fsgid, cred, perm, flags, NULL);  in __key_create_or_update()
953 	if (index_key.type->preparse)  in __key_create_or_update()
954 		index_key.type->free_preparse(&prep);  in __key_create_or_update()
962 	 * - we can drop the locks first as we have the key pinned  in __key_create_or_update()
967 	if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) {  in __key_create_or_update()
986  * key_create_or_update - Update or create and instantiate a key.
1002  * Returns a pointer to the new key if successful, -ENODEV if the key type
1003  * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the
1024  * key_create - Create and instantiate a key.
1038  * Returns a pointer to the new key if successful, -EEXIST if a key with the
1039  * same description already exists, -ENODEV if the key type wasn't available,
1040  * -ENOTDIR if the keyring wasn't a keyring, -EACCES if the caller isn't
1061  * key_update - Update a key's contents.
1070  * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key
1087 	if (!key->type->update)  in key_update()
1088 		return -EOPNOTSUPP;  in key_update()
1093 	prep.quotalen = key->type->def_datalen;  in key_update()
1095 	if (key->type->preparse) {  in key_update()
1096 		ret = key->type->preparse(&prep);  in key_update()
1101 	down_write(&key->sem);  in key_update()
1103 	ret = key->type->update(key, &prep);  in key_update()
1110 	up_write(&key->sem);  in key_update()
1113 	if (key->type->preparse)  in key_update()
1114 		key->type->free_preparse(&prep);  in key_update()
1120  * key_revoke - Revoke a key.
1135 	 * - we tell lockdep that we might nest because we might be revoking an  in key_revoke()
1139 	down_write_nested(&key->sem, 1);  in key_revoke()
1140 	if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags)) {  in key_revoke()
1142 		if (key->type->revoke)  in key_revoke()
1143 			key->type->revoke(key);  in key_revoke()
1147 		if (key->revoked_at == 0 || key->revoked_at > time) {  in key_revoke()
1148 			key->revoked_at = time;  in key_revoke()
1149 			key_schedule_gc(key->revoked_at + key_gc_delay);  in key_revoke()
1153 	up_write(&key->sem);  in key_revoke()
1158  * key_invalidate - Invalidate a key.
1170 	if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) {  in key_invalidate()
1171 		down_write_nested(&key->sem, 1);  in key_invalidate()
1172 		if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) {  in key_invalidate()
1176 		up_write(&key->sem);  in key_invalidate()
1182  * generic_key_instantiate - Simple instantiation of a key from preparsed data
1197 	ret = key_payload_reserve(key, prep->quotalen);  in generic_key_instantiate()
1199 		rcu_assign_keypointer(key, prep->payload.data[0]);  in generic_key_instantiate()
1200 		key->payload.data[1] = prep->payload.data[1];  in generic_key_instantiate()
1201 		key->payload.data[2] = prep->payload.data[2];  in generic_key_instantiate()
1202 		key->payload.data[3] = prep->payload.data[3];  in generic_key_instantiate()
1203 		prep->payload.data[0] = NULL;  in generic_key_instantiate()
1204 		prep->payload.data[1] = NULL;  in generic_key_instantiate()
1205 		prep->payload.data[2] = NULL;  in generic_key_instantiate()
1206 		prep->payload.data[3] = NULL;  in generic_key_instantiate()
1214  * register_key_type - Register a type of key.
1219  * Returns 0 on success or -EEXIST if a type of this name already exists.
1226 	memset(&ktype->lock_class, 0, sizeof(ktype->lock_class));  in register_key_type()
1228 	ret = -EEXIST;  in register_key_type()
1233 		if (strcmp(p->name, ktype->name) == 0)  in register_key_type()
1238 	list_add(&ktype->link, &key_types_list);  in register_key_type()
1240 	pr_notice("Key type %s registered\n", ktype->name);  in register_key_type()
1250  * unregister_key_type - Unregister a type of key.
1260 	list_del_init(&ktype->link);  in unregister_key_type()
1263 	pr_notice("Key type %s unregistered\n", ktype->name);  in unregister_key_type()
1269  * Initialise the key management state.