From 6c1976addf3623e979b7a954e216004d559bcb42 Mon Sep 17 00:00:00 2001 From: Thomas Weißschuh Date: Mon, 9 Jan 2023 23:59:42 +0000 Subject: KEYS: Add new function key_create() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit key_create() works like key_create_or_update() but does not allow updating an existing key, instead returning ERR_PTR(-EEXIST). key_create() will be used by the blacklist keyring which should not create duplicate entries or update existing entries. Instead a dedicated message with appropriate severity will be logged. Signed-off-by: Thomas Weißschuh Signed-off-by: Jarkko Sakkinen --- security/keys/key.c | 137 ++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 100 insertions(+), 37 deletions(-) (limited to 'security') diff --git a/security/keys/key.c b/security/keys/key.c index c45afdd1dfbb..5c0c7df833f8 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -788,38 +788,18 @@ 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 +886,23 @@ 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 */ @@ -985,8 +974,82 @@ error: 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. -- cgit v1.2.3