diff options
Diffstat (limited to 'security/keys/key.c')
| -rw-r--r-- | security/keys/key.c | 199 |
1 files changed, 136 insertions, 63 deletions
diff --git a/security/keys/key.c b/security/keys/key.c index c45afdd1dfbb..3bbdde778631 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -13,7 +13,6 @@ #include <linux/security.h> #include <linux/workqueue.h> #include <linux/random.h> -#include <linux/ima.h> #include <linux/err.h> #include "internal.h" @@ -231,6 +230,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, struct key *key; size_t desclen, quotalen; int ret; + unsigned long irqflags; key = ERR_PTR(-EINVAL); if (!desc || !*desc) @@ -260,7 +260,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; - spin_lock(&user->lock); + spin_lock_irqsave(&user->lock, irqflags); if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { if (user->qnkeys + 1 > maxkeys || user->qnbytes + quotalen > maxbytes || @@ -270,7 +270,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, user->qnkeys++; user->qnbytes += quotalen; - spin_unlock(&user->lock); + spin_unlock_irqrestore(&user->lock, irqflags); } /* allocate and initialise the key and its description */ @@ -294,9 +294,11 @@ struct key *key_alloc(struct key_type *type, const char *desc, key->uid = uid; key->gid = gid; key->perm = perm; + key->expiry = TIME64_MAX; key->restrict_link = restrict_link; key->last_used_at = ktime_get_real_seconds(); + key->flags |= 1 << KEY_FLAG_USER_ALIVE; if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) key->flags |= 1 << KEY_FLAG_IN_QUOTA; if (flags & KEY_ALLOC_BUILT_IN) @@ -327,10 +329,10 @@ security_error: kfree(key->description); kmem_cache_free(key_jar, key); if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { - spin_lock(&user->lock); + spin_lock_irqsave(&user->lock, irqflags); user->qnkeys--; user->qnbytes -= quotalen; - spin_unlock(&user->lock); + spin_unlock_irqrestore(&user->lock, irqflags); } key_user_put(user); key = ERR_PTR(ret); @@ -340,10 +342,10 @@ no_memory_3: kmem_cache_free(key_jar, key); no_memory_2: if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { - spin_lock(&user->lock); + spin_lock_irqsave(&user->lock, irqflags); user->qnkeys--; user->qnbytes -= quotalen; - spin_unlock(&user->lock); + spin_unlock_irqrestore(&user->lock, irqflags); } key_user_put(user); no_memory_1: @@ -351,7 +353,7 @@ no_memory_1: goto error; no_quota: - spin_unlock(&user->lock); + spin_unlock_irqrestore(&user->lock, irqflags); key_user_put(user); key = ERR_PTR(-EDQUOT); goto error; @@ -380,8 +382,9 @@ int key_payload_reserve(struct key *key, size_t datalen) if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; + unsigned long flags; - spin_lock(&key->user->lock); + spin_lock_irqsave(&key->user->lock, flags); if (delta > 0 && (key->user->qnbytes + delta > maxbytes || @@ -392,7 +395,7 @@ int key_payload_reserve(struct key *key, size_t datalen) key->user->qnbytes += delta; key->quotalen += delta; } - spin_unlock(&key->user->lock); + spin_unlock_irqrestore(&key->user->lock, flags); } /* change the recorded data length if that didn't generate an error */ @@ -463,10 +466,8 @@ static int __key_instantiate_and_link(struct key *key, if (authkey) key_invalidate(authkey); - if (prep->expiry != TIME64_MAX) { - key->expiry = prep->expiry; - key_schedule_gc(prep->expiry + key_gc_delay); - } + if (prep->expiry != TIME64_MAX) + key_set_expiry(key, prep->expiry); } } @@ -606,8 +607,7 @@ int key_reject_and_link(struct key *key, atomic_inc(&key->user->nikeys); mark_key_instantiated(key, -error); notify_key(key, NOTIFY_KEY_INSTANTIATED, -error); - key->expiry = ktime_get_real_seconds() + timeout; - key_schedule_gc(key->expiry + key_gc_delay); + key_set_expiry(key, ktime_get_real_seconds() + timeout); if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) awaken = 1; @@ -649,8 +649,20 @@ void key_put(struct key *key) if (key) { key_check(key); - if (refcount_dec_and_test(&key->usage)) + if (refcount_dec_and_test(&key->usage)) { + unsigned long flags; + + /* deal with the user's key tracking and quota */ + if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { + spin_lock_irqsave(&key->user->lock, flags); + key->user->qnkeys--; + key->user->qnbytes -= key->quotalen; + spin_unlock_irqrestore(&key->user->lock, flags); + } + /* Mark key as safe for GC after key->user done. */ + clear_bit_unlock(KEY_FLAG_USER_ALIVE, &key->flags); schedule_work(&key_gc_work); + } } } EXPORT_SYMBOL(key_put); @@ -693,6 +705,7 @@ error: spin_unlock(&key_serial_lock); return key; } +EXPORT_SYMBOL(key_lookup); /* * Find and lock the specified key type against removal. @@ -722,16 +735,14 @@ found_kernel_type: void key_set_timeout(struct key *key, unsigned timeout) { - time64_t expiry = 0; + time64_t expiry = TIME64_MAX; /* make the changes with the locks held to prevent races */ down_write(&key->sem); if (timeout > 0) expiry = ktime_get_real_seconds() + timeout; - - key->expiry = expiry; - key_schedule_gc(key->expiry + key_gc_delay); + key_set_expiry(key, expiry); up_write(&key->sem); } @@ -788,38 +799,18 @@ error: goto out; } -/** - * key_create_or_update - Update or create and instantiate a key. - * @keyring_ref: A pointer to the destination keyring with possession flag. - * @type: The type of key. - * @description: The searchable description for the key. - * @payload: The data to use to instantiate or update the key. - * @plen: The length of @payload. - * @perm: The permissions mask for a new key. - * @flags: The quota flags for a new key. - * - * Search the destination keyring for a key of the same description and if one - * is found, update it, otherwise create and instantiate a new one and create a - * link to it from that keyring. - * - * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be - * concocted. - * - * Returns a pointer to the new key if successful, -ENODEV if the key type - * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the - * caller isn't permitted to modify the keyring or the LSM did not permit - * creation of the key. - * - * On success, the possession flag from the keyring ref will be tacked on to - * the key ref before it is returned. +/* + * Create or potentially update a key. The combined logic behind + * key_create_or_update() and key_create() */ -key_ref_t key_create_or_update(key_ref_t keyring_ref, - const char *type, - const char *description, - const void *payload, - size_t plen, - key_perm_t perm, - unsigned long flags) +static key_ref_t __key_create_or_update(key_ref_t keyring_ref, + const char *type, + const char *description, + const void *payload, + size_t plen, + key_perm_t perm, + unsigned long flags, + bool allow_update) { struct keyring_index_key index_key = { .description = description, @@ -906,14 +897,23 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, goto error_link_end; } - /* if it's possible to update this type of key, search for an existing - * key of the same type and description in the destination keyring and - * update that instead if possible + /* if it's requested and possible to update this type of key, search + * for an existing key of the same type and description in the + * destination keyring and update that instead if possible */ - if (index_key.type->update) { + if (allow_update) { + if (index_key.type->update) { + key_ref = find_key_to_update(keyring_ref, &index_key); + if (key_ref) + goto found_matching_key; + } + } else { key_ref = find_key_to_update(keyring_ref, &index_key); - if (key_ref) - goto found_matching_key; + if (key_ref) { + key_ref_put(key_ref); + key_ref = ERR_PTR(-EEXIST); + goto error_link_end; + } } /* if the client doesn't provide, decide on the permissions we want */ @@ -945,8 +945,8 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, goto error_link_end; } - ima_post_key_create_or_update(keyring, key, payload, plen, - flags, true); + security_key_post_create_or_update(keyring, key, payload, plen, flags, + true); key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); @@ -979,15 +979,88 @@ error: key_ref = __key_update(key_ref, &prep); if (!IS_ERR(key_ref)) - ima_post_key_create_or_update(keyring, key, - payload, plen, - flags, false); + security_key_post_create_or_update(keyring, key, payload, plen, + flags, false); goto error_free_prep; } + +/** + * key_create_or_update - Update or create and instantiate a key. + * @keyring_ref: A pointer to the destination keyring with possession flag. + * @type: The type of key. + * @description: The searchable description for the key. + * @payload: The data to use to instantiate or update the key. + * @plen: The length of @payload. + * @perm: The permissions mask for a new key. + * @flags: The quota flags for a new key. + * + * Search the destination keyring for a key of the same description and if one + * is found, update it, otherwise create and instantiate a new one and create a + * link to it from that keyring. + * + * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be + * concocted. + * + * Returns a pointer to the new key if successful, -ENODEV if the key type + * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the + * caller isn't permitted to modify the keyring or the LSM did not permit + * creation of the key. + * + * On success, the possession flag from the keyring ref will be tacked on to + * the key ref before it is returned. + */ +key_ref_t key_create_or_update(key_ref_t keyring_ref, + const char *type, + const char *description, + const void *payload, + size_t plen, + key_perm_t perm, + unsigned long flags) +{ + return __key_create_or_update(keyring_ref, type, description, payload, + plen, perm, flags, true); +} EXPORT_SYMBOL(key_create_or_update); /** + * key_create - Create and instantiate a key. + * @keyring_ref: A pointer to the destination keyring with possession flag. + * @type: The type of key. + * @description: The searchable description for the key. + * @payload: The data to use to instantiate or update the key. + * @plen: The length of @payload. + * @perm: The permissions mask for a new key. + * @flags: The quota flags for a new key. + * + * Create and instantiate a new key and link to it from the destination keyring. + * + * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be + * concocted. + * + * Returns a pointer to the new key if successful, -EEXIST if a key with the + * same description already exists, -ENODEV if the key type wasn't available, + * -ENOTDIR if the keyring wasn't a keyring, -EACCES if the caller isn't + * permitted to modify the keyring or the LSM did not permit creation of the + * key. + * + * On success, the possession flag from the keyring ref will be tacked on to + * the key ref before it is returned. + */ +key_ref_t key_create(key_ref_t keyring_ref, + const char *type, + const char *description, + const void *payload, + size_t plen, + key_perm_t perm, + unsigned long flags) +{ + return __key_create_or_update(keyring_ref, type, description, payload, + plen, perm, flags, false); +} +EXPORT_SYMBOL(key_create); + +/** * key_update - Update a key's contents. * @key_ref: The pointer (plus possession flag) to the key. * @payload: The data to be used to update the key. |
