From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753351Ab3JWUek (ORCPT ); Wed, 23 Oct 2013 16:34:40 -0400 Received: from relay3.sgi.com ([192.48.152.1]:47744 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751709Ab3JWUej (ORCPT ); Wed, 23 Oct 2013 16:34:39 -0400 Date: Wed, 23 Oct 2013 15:34:35 -0500 From: Ben Myers To: Geyslan =?iso-8859-1?Q?Greg=F3rio?= Bem Cc: Eric Sandeen , Alex Elder , open list , XFS FILESYSTEM Subject: Re: [PATCH] xfs: fix possible NULL dereference Message-ID: <20131023203435.GR1935@sgi.com> References: <20131021231849.GL10553@sgi.com> <20131021235601.GG4446@dastard> <5265C03B.50701@sandeen.net> <20131022001732.GI4446@dastard> <20131022203946.GB2797@dastard> <5266E4BD.8030601@sandeen.net> <20131022210300.GC2797@dastard> <5266EBF0.901@sandeen.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey Geyslan, On Wed, Oct 23, 2013 at 08:58:51AM -0200, Geyslan Gregório Bem wrote: > - Regarding the "possible new patch" subject, I humbly pass the ball to you. > > Thank you for the attention. Thank you for the patch. I would really prefer to commit this showing authorship from you, rather than a Reported-by. Can I mark you down? Regards, Ben --- xfs: fix possible NULL dereference in xlog_verify_iclog In xlog_verify_iclog a debug check of the incore log buffers prints an error if icptr is null and then goes on to dereference the pointer regardless. Convert this to an assert so that the intention is clear. This was reported by Coverty. Reported-by: Geyslan G. Bem Signed-off-by: Ben Myers --- fs/xfs/xfs_log.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) Index: b/fs/xfs/xfs_log.c =================================================================== --- a/fs/xfs/xfs_log.c 2013-10-23 14:52:47.875216875 -0500 +++ b/fs/xfs/xfs_log.c 2013-10-23 14:53:53.775245830 -0500 @@ -3714,11 +3714,9 @@ xlog_verify_iclog( /* check validity of iclog pointers */ spin_lock(&log->l_icloglock); icptr = log->l_iclog; - for (i=0; i < log->l_iclog_bufs; i++) { - if (icptr == NULL) - xfs_emerg(log->l_mp, "%s: invalid ptr", __func__); - icptr = icptr->ic_next; - } + for (i=0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next) + ASSERT(icptr); + if (icptr != log->l_iclog) xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__); spin_unlock(&log->l_icloglock);