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From: Alexander Potapenko <glider@google.com>
Date: Thu, 14 Dec 2023 15:55:00 +0100
Message-ID: <CAG_fn=UukAf5sPrwqQtmL7-_dyUs3neBpa75JAaeACUzXsHwOA@mail.gmail.com>
Subject: Re: [syzbot] [crypto?] KMSAN: uninit-value in __crc32c_le_base (3)
To: Dave Chinner <david@fromorbit.com>
Cc: Dave Chinner <dchinner@redhat.com>, 
	syzbot+a6d6b8fffa294705dbd8@syzkaller.appspotmail.com, hch@lst.de, 
	davem@davemloft.net, herbert@gondor.apana.org.au, 
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, 
	syzkaller-bugs@googlegroups.com, linux-xfs@vger.kernel.org
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On Wed, Dec 13, 2023 at 10:58=E2=80=AFPM 'Dave Chinner' via syzkaller-bugs
<syzkaller-bugs@googlegroups.com> wrote:
>
> On Thu, Dec 14, 2023 at 08:16:07AM +1100, Dave Chinner wrote:
> > [cc linux-xfs@vger.kernel.org because that's where all questions
> > about XFS stuff should be directed, not to random individual
> > developers. ]
> >
> > On Wed, Dec 13, 2023 at 11:49:50AM +0100, Alexander Potapenko wrote:
> > > Hi Christoph, Dave,
> > >
> > > The repro provided by Xingwei indeed works.
>
> Can you please test the patch below?

It fixed the problem for me, feel free to add:

Tested-by: Alexander Potapenko <glider@google.com>

As for the time needed to detect the bug, note that kmemcheck was
never used together with syzkaller, so it couldn't have the chance to
find it.

KMSAN found this bug in April
(https://syzkaller.appspot.com/bug?extid=3Da6d6b8fffa294705dbd8), only
half a year after we started mounting XFS images on syzbot.
Right now it is among the top crashers, so fixing it might uncover
more interesting bugs in xfs.