[3.13.y-ckt stable] Patch "KEYS: ensure we free the assoc array edit if edit is valid" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    KEYS: ensure we free the assoc array edit if edit is valid

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt25.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From f86e37eb4b5f25ad2bcb03904246b54843639c48 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king at canonical.com>
Date: Mon, 27 Jul 2015 15:23:43 +0100
Subject: KEYS: ensure we free the assoc array edit if edit is valid

commit ca4da5dd1f99fe9c59f1709fb43e818b18ad20e0 upstream.

__key_link_end is not freeing the associated array edit structure
and this leads to a 512 byte memory leak each time an identical
existing key is added with add_key().

The reason the add_key() system call returns okay is that
key_create_or_update() calls __key_link_begin() before checking to see
whether it can update a key directly rather than adding/replacing - which
it turns out it can.  Thus __key_link() is not called through
__key_instantiate_and_link() and __key_link_end() must cancel the edit.

CVE-2015-1333

Signed-off-by: Colin Ian King <colin.king at canonical.com>
Signed-off-by: David Howells <dhowells at redhat.com>
Signed-off-by: James Morris <james.l.morris at oracle.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 security/keys/keyring.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index d46cbc5..eefe216 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -1147,9 +1147,11 @@ void __key_link_end(struct key *keyring,
 	if (index_key->type == &key_type_keyring)
 		up_write(&keyring_serialise_link_sem);

-	if (edit && !edit->dead_leaf) {
-		key_payload_reserve(keyring,
-				    keyring->datalen - KEYQUOTA_LINK_BYTES);
+	if (edit) {
+		if (!edit->dead_leaf) {
+			key_payload_reserve(keyring,
+				keyring->datalen - KEYQUOTA_LINK_BYTES);
+		}
 		assoc_array_cancel_edit(edit);
 	}
 	up_write(&keyring->sem);
--
1.9.1