This is a note to let you know that I've just added the patch titled

KEYS: Don't permit request_key() to construct a new keyring

to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: keys-don-t-permit-request_key-to-construct-a-new-keyring.patch and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 911b79cde95c7da0ec02f48105358a36636b7a71 Mon Sep 17 00:00:00 2001

From: David Howells dhowells@redhat.com Date: Mon, 19 Oct 2015 11:20:28 +0100 Subject: KEYS: Don't permit request_key() to construct a new keyring

From: David Howells dhowells@redhat.com

commit 911b79cde95c7da0ec02f48105358a36636b7a71 upstream.

If request_key() is used to find a keyring, only do the search part - don't do the construction part if the keyring was not found by the search. We don't really want keyrings in the negative instantiated state since the rejected/negative instantiation error value in the payload is unioned with keyring metadata.

Now the kernel gives an error:

request_key("keyring", "#selinux,bdekeyring", "keyring", KEY_SPEC_USER_SESSION_KEYRING) = -1 EPERM (Operation not permitted)

Signed-off-by: David Howells dhowells@redhat.com Signed-off-by: Eric Biggers ebiggers@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- security/keys/request_key.c | 3 +++ 1 file changed, 3 insertions(+)

--- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -467,6 +467,9 @@ static struct key *construct_key_and_lin if (ret) goto error;

+ if (ctx->index_key.type == &key_type_keyring) + return ERR_PTR(-EPERM); + user = key_user_lookup(current_fsuid()); if (!user) { ret = -ENOMEM;

Patches currently in stable-queue which might be from dhowells@redhat.com are

queue-3.18/keys-don-t-permit-request_key-to-construct-a-new-keyring.patch queue-3.18/don-t-leak-a-key-reference-if-request_key-tries-to-use-a-revoked-keyring.patch