From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932244AbZKFWW3 (ORCPT ); Fri, 6 Nov 2009 17:22:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760094AbZKFWW0 (ORCPT ); Fri, 6 Nov 2009 17:22:26 -0500 Received: from kroah.org ([198.145.64.141]:56659 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760073AbZKFWWZ (ORCPT ); Fri, 6 Nov 2009 17:22:25 -0500 X-Mailbox-Line: From gregkh@mini.kroah.org Fri Nov 6 14:15:40 2009 Message-Id: <20091106221540.027407931@mini.kroah.org> User-Agent: quilt/0.48-1 Date: Fri, 06 Nov 2009 14:14:08 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Darren Hart , Peter Zijlstra , Ingo Molnar , Eric Dumazet , Dinakar Guniguntala , John Stultz , Thomas Gleixner Subject: [10/99] futex: Check for NULL keys in match_futex References: <20091106221358.309857998@mini.kroah.org> Content-Disposition: inline; filename=futex-check-for-null-keys-in-match_futex.patch In-Reply-To: <20091106221850.GA15408@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Darren Hart commit 2bc872036e1c5948b5b02942810bbdd8dbdb9812 upstream. If userspace tries to perform a requeue_pi on a non-requeue_pi waiter, it will find the futex_q->requeue_pi_key to be NULL and OOPS. Check for NULL in match_futex() instead of doing explicit NULL pointer checks on all call sites. While match_futex(NULL, NULL) returning false is a little odd, it's still correct as we expect valid key references. Signed-off-by: Darren Hart Cc: Peter Zijlstra Cc: Ingo Molnar CC: Eric Dumazet CC: Dinakar Guniguntala CC: John Stultz LKML-Reference: <4AD60687.10306@us.ibm.com> Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- kernel/futex.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/kernel/futex.c +++ b/kernel/futex.c @@ -150,7 +150,8 @@ static struct futex_hash_bucket *hash_fu */ static inline int match_futex(union futex_key *key1, union futex_key *key2) { - return (key1->both.word == key2->both.word + return (key1 && key2 + && key1->both.word == key2->both.word && key1->both.ptr == key2->both.ptr && key1->both.offset == key2->both.offset); }