diff options
| -rw-r--r-- | security/keys/request_key.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 07a0ef2baacd..a7673ad86d18 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -401,17 +401,21 @@ static int construct_alloc_key(struct keyring_search_context *ctx, set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); if (dest_keyring) { - ret = __key_link_lock(dest_keyring, &ctx->index_key); + ret = __key_link_lock(dest_keyring, &key->index_key); if (ret < 0) goto link_lock_failed; - ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit); - if (ret < 0) - goto link_prealloc_failed; } - /* attach the key to the destination keyring under lock, but we do need + /* + * Attach the key to the destination keyring under lock, but we do need * to do another check just in case someone beat us to it whilst we - * waited for locks */ + * waited for locks. + * + * The caller might specify a comparison function which looks for keys + * that do not exactly match but are still equivalent from the caller's + * perspective. The __key_link_begin() operation must be done only after + * an actual key is determined. + */ mutex_lock(&key_construction_mutex); rcu_read_lock(); @@ -420,12 +424,16 @@ static int construct_alloc_key(struct keyring_search_context *ctx, if (!IS_ERR(key_ref)) goto key_already_present; - if (dest_keyring) + if (dest_keyring) { + ret = __key_link_begin(dest_keyring, &key->index_key, &edit); + if (ret < 0) + goto link_alloc_failed; __key_link(dest_keyring, key, &edit); + } mutex_unlock(&key_construction_mutex); if (dest_keyring) - __key_link_end(dest_keyring, &ctx->index_key, edit); + __key_link_end(dest_keyring, &key->index_key, edit); mutex_unlock(&user->cons_lock); *_key = key; kleave(" = 0 [%d]", key_serial(key)); @@ -438,10 +446,13 @@ key_already_present: mutex_unlock(&key_construction_mutex); key = key_ref_to_ptr(key_ref); if (dest_keyring) { + ret = __key_link_begin(dest_keyring, &key->index_key, &edit); + if (ret < 0) + goto link_alloc_failed_unlocked; ret = __key_link_check_live_key(dest_keyring, key); if (ret == 0) __key_link(dest_keyring, key, &edit); - __key_link_end(dest_keyring, &ctx->index_key, edit); + __key_link_end(dest_keyring, &key->index_key, edit); if (ret < 0) goto link_check_failed; } @@ -456,8 +467,10 @@ link_check_failed: kleave(" = %d [linkcheck]", ret); return ret; -link_prealloc_failed: - __key_link_end(dest_keyring, &ctx->index_key, edit); +link_alloc_failed: + mutex_unlock(&key_construction_mutex); +link_alloc_failed_unlocked: + __key_link_end(dest_keyring, &key->index_key, edit); link_lock_failed: mutex_unlock(&user->cons_lock); key_put(key); |