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

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

[ Upstream commit HEAD ]

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>
(cherry picked from commit c9cd9b18dac801040ada16562dc579d5ac366d75)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
[mainline backport of commit 66db51c9f7b2fe7ebdfa753b2aa9abbb9feddc87]
Change-Id: I00cf148142abfc956609aeb35b030b4d1bba16e6
Signed-off-by: Jaechul Lee <jcsing.lee@samsung.com>