Patch "KEYS: ensure we free the assoc array edit if edit is valid" has been added to the 4.1-stable tree

Patch "KEYS: ensure we free the assoc array edit if edit is valid" has been added to the 4.1-stable tree

[gregkh]

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

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

to the 4.1-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-ensure-we-free-the-assoc-array-edit-if-edit-is-valid.patch
and it can be found in the queue-4.1 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 ca4da5dd1f99fe9c59f1709fb43e818b18ad20e0 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Mon, 27 Jul 2015 15:23:43 +0100
Subject: KEYS: ensure we free the assoc array edit if edit is valid

From: Colin Ian King <colin.king@canonical.com>

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@canonical.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 security/keys/keyring.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -1181,9 +1181,11 @@ 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);


Patches currently in stable-queue which might be from colin.king@canonical.com are

queue-4.1/keys-ensure-we-free-the-assoc-array-edit-if-edit-is-valid.patch