[PATCH] Keys: Replace duplicate non-updateable keys rather than failing
Cause an attempt to add a duplicate non-updateable key (such as a keyring) to
a keyring to discard the extant copy in favour of the new one rather than
failing with EEXIST:
# do the test in an empty session
keyctl session
# create a new keyring called "a" and attach to session
keyctl newring a @s
# create another new keyring called "a" and attach to session,
# displacing the keyring added by the second command:
keyctl newring a @s
Without this patch, the third command will fail.
For updateable keys (such as those of "user" type), the update method will
still be called rather than a new key being created.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/security/keys/key.c b/security/keys/key.c
index 6276971..a057e33 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -795,12 +795,16 @@
goto error_3;
}
- /* search for an existing key of the same type and description in the
- * destination keyring
+ /* 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
*/
- key_ref = __keyring_search_one(keyring_ref, ktype, description, 0);
- if (!IS_ERR(key_ref))
- goto found_matching_key;
+ if (ktype->update) {
+ key_ref = __keyring_search_one(keyring_ref, ktype, description,
+ 0);
+ if (!IS_ERR(key_ref))
+ goto found_matching_key;
+ }
/* decide on the permissions we want */
perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;