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;a=summary
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@xxxxxxxxxxxxxxx> know about it.
>From 911b79cde95c7da0ec02f48105358a36636b7a71 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@xxxxxxxxxx>
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@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxx 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