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From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Dave Chinner <david@fromorbit.com>
Cc: Dmitry Vyukov <dvyukov@google.com>,
	syzbot <syzbot+84a67953651a971809ba@syzkaller.appspotmail.com>,
	"Darrick J. Wong" <darrick.wong@oracle.com>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-xfs@vger.kernel.org,
	syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Subject: Re: WARNING: bad unlock balance in xfs_iunlock
Date: Wed, 9 May 2018 09:55:28 -0400	[thread overview]
Message-ID: <20180509135528.GE28388@thunk.org> (raw)
In-Reply-To: <20180509005011.GP23861@dastard>

>>> 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

A suggestion --- insteading of forcing human beings --- either
overworked file system developers, or understaffed fuzzing tool teams,
to have to manually pull out the file system image out from the C
repro, if it's too hard to add a link where the file system iamge can
be downloaded from the Syzkaller web application --- how about adding
an option to the C repro template which causes it to dump the image to
a file and then immediately exit?

					- Ted

  parent reply	other threads:[~2018-05-09 13:55 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-03  2:01 WARNING: bad unlock balance in xfs_iunlock syzbot
2018-04-03  4:38 ` Dave Chinner
2018-04-05 18:54   ` Dmitry Vyukov
2018-04-05 21:38     ` Dave Chinner
2018-04-06 16:10       ` Darrick J. Wong
2018-04-13 10:03         ` Dmitry Vyukov
2018-04-16 19:22           ` Eric Sandeen
2018-04-30 13:23             ` Dmitry Vyukov
2018-04-30 13:49               ` Eric Sandeen
2018-04-30 14:02                 ` Dmitry Vyukov
2018-04-30 15:14                   ` Eric Sandeen
2018-05-02  9:54                     ` Jan Tulak
2018-05-08  7:52                     ` Dmitry Vyukov
2018-05-09  2:48                       ` Eric Sandeen
2018-05-09  8:43                         ` Dmitry Vyukov
2018-05-09 23:22                           ` Dave Chinner
2018-05-11  8:59                             ` Dmitry Vyukov
2018-05-12  1:16                               ` Dave Chinner
2018-05-08  7:54                     ` Dmitry Vyukov
2018-04-30 13:24     ` Dmitry Vyukov
2018-05-01 22:51       ` Dave Chinner
2018-05-08  7:56         ` Dmitry Vyukov
2018-05-09  0:50           ` Dave Chinner
2018-05-09  2:37             ` Eric Biggers
2018-05-09  3:32               ` Eric Sandeen
2018-05-09 13:55             ` Theodore Y. Ts'o [this message]
2018-05-09 14:13               ` Dmitry Vyukov

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