From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933639AbeEICfa (ORCPT ); Tue, 8 May 2018 22:35:30 -0400 Received: from mail-pl0-f67.google.com ([209.85.160.67]:35989 "EHLO mail-pl0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932526AbeEICf1 (ORCPT ); Tue, 8 May 2018 22:35:27 -0400 X-Google-Smtp-Source: AB8JxZpDI1PUPZDwjj4dkB4tLjYLPecdcMlhmHwRR+yiHXoRCR4jJsqdaQFcFCZVe7os64Z5wTi3Lg== Date: Tue, 8 May 2018 19:37:21 -0700 From: Eric Biggers To: Dave Chinner Cc: Dmitry Vyukov , syzbot , "Darrick J. Wong" , LKML , linux-xfs@vger.kernel.org, syzkaller-bugs Subject: Re: WARNING: bad unlock balance in xfs_iunlock Message-ID: <20180509023721.GA711@sol.localdomain> References: <20180403043854.GL1150@dastard> <20180501225159.GY23861@dastard> <20180509005011.GP23861@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180509005011.GP23861@dastard> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 09, 2018 at 10:50:11AM +1000, Dave Chinner wrote: > On Tue, May 08, 2018 at 09:56:01AM +0200, Dmitry Vyukov wrote: > > On Wed, May 2, 2018 at 12:51 AM, Dave Chinner wrote: > > >> >>> Hello, > > >> >>> > > >> >>> syzbot hit the following crash on upstream commit > > >> >>> 86bbbebac1933e6e95e8234c4f7d220c5ddd38bc (Mon Apr 2 18:47:07 2018 +0000) > > >> >>> Merge branch 'ras-core-for-linus' of > > >> >>> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip > > >> >>> syzbot dashboard link: > > >> >>> https://syzkaller.appspot.com/bug?extid=84a67953651a971809ba > > >> >>> > > >> >>> C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5719304272084992 > > >> >>> syzkaller reproducer: > > >> >>> https://syzkaller.appspot.com/x/repro.syz?id=5767783983874048 > > >> >> > > >> >> What a mess. A hand built, hopelessly broken filesystem image made > > >> >> up of hex dumps, written into a mmap()d region of memory, then > > >> >> copied into a tmpfs file and mounted with the loop device. > > >> >> > > >> >> Engineers that can debug broken filesystems don't grow on trees. If > > >> >> we are to have any hope of understanding what the hell this test is > > >> >> doing, the bot needs to supply us with a copy of the built > > >> >> filesystem image the test uses. We need to be able to point forensic > > >> >> tools at the image to decode all the structures into human readable > > >> >> format - if we are forced to do that by hand or jump through hoops > > >> >> to create our own filesystem image than I'm certainly not going to > > >> >> waste time looking at these reports... > > >> > > > >> > Hi Dave, > > >> > > > >> > Here is the image: > > >> > https://drive.google.com/file/d/1jzhGGe5SBJcqfsjxCLHoh4Kazke1oTfC/view > > >> > > >> Have anybody looked at the bug and the image yet? > > > > > > Yes, I did that a couple of weeks ago. Couldn't reproduce on a TOT > > > kernel here. > > > > Do you think it is fixed now? What fixed it? The bug was there. > > We merge fixes for fuzzing issues all the time. IIRC a big batch of > them from the xfstests fuzzing infrastructure went into 4.17-rc1. > > If you want a commit, then do a bisect.... > The fix was commit 8241f7f983b9728: #syz fix: xfs: don't iunlock the quota ip when quota block - Eric