This function works like key_create_or_update() but does not allow
updating an existing key, instead returning -EEXIST.
This new function will be used by the blacklist keyring to handle EEXIST
errors specially by logging a different message with lower severity.
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
include/linux/key.h | 8 +++
security/keys/key.c | 149 +++++++++++++++++++++++++++++++++-----------
2 files changed, 120 insertions(+), 37 deletions(-)
diff --git a/include/linux/key.h b/include/linux/key.h
index d27477faf00d..8dc7f7c3088b 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -386,6 +386,14 @@ extern int wait_for_key_construction(struct key *key, bool intr);
extern int key_validate(const struct key *key);
+extern key_ref_t key_create(key_ref_t keyring,
+ const char *type,
+ const char *description,
+ const void *payload,
+ size_t plen,
+ key_perm_t perm,
+ unsigned long flags);
+
extern key_ref_t key_create_or_update(key_ref_t keyring,
const char *type,
const char *description,
diff --git a/security/keys/key.c b/security/keys/key.c
index c45afdd1dfbb..f84bcd8457f4 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -788,38 +788,18 @@ static inline key_ref_t __key_update(key_ref_t key_ref,
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 +974,94 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
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.
--
2.38.1
