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From:   Johannes Thumshirn <Johannes.Thumshirn@wdc.com>
To:     syzbot <syzbot+e864a35d361e1d4e29a5@syzkaller.appspotmail.com>,
        "anand.jain@oracle.com" <anand.jain@oracle.com>,
        "clm@fb.com" <clm@fb.com>, "dsterba@suse.com" <dsterba@suse.com>,
        "josef@toxicpanda.com" <josef@toxicpanda.com>,
        "jthumshirn@suse.de" <jthumshirn@suse.de>,
        "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "syzkaller-bugs@googlegroups.com" <syzkaller-bugs@googlegroups.com>
Subject: Re: kernel BUG at lib/string.c:LINE! (5)
Thread-Topic: kernel BUG at lib/string.c:LINE! (5)
Thread-Index: AQHWi1Aw47gymd3CJ0Ciy/1hIPgGyg==
Date:   Wed, 16 Sep 2020 08:45:32 +0000
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On 16/09/2020 10:19, syzbot wrote:=0A=
> syzbot has bisected this issue to:=0A=
> =0A=
> commit 3951e7f050ac6a38bbc859fc3cd6093890c31d1c=0A=
> Author: Johannes Thumshirn <jthumshirn@suse.de>=0A=
> Date:   Mon Oct 7 09:11:01 2019 +0000=0A=
> =0A=
>     btrfs: add xxhash64 to checksumming algorithms=0A=
> =0A=
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=3D10aadcc590=
0000=0A=
> start commit:   e4c26faa Merge tag 'usb-5.9-rc5' of git://git.kernel.org/=
p..=0A=
> git tree:       upstream=0A=
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=3D12aadcc590=
0000=0A=
> console output: https://syzkaller.appspot.com/x/log.txt?x=3D14aadcc590000=
0=0A=
> kernel config:  https://syzkaller.appspot.com/x/.config?x=3Dc61610091f4ca=
8c4=0A=
> dashboard link: https://syzkaller.appspot.com/bug?extid=3De864a35d361e1d4=
e29a5=0A=
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=3D177582be900=
000=0A=
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=3D13deb2b590000=
0=0A=
> =0A=
> Reported-by: syzbot+e864a35d361e1d4e29a5@syzkaller.appspotmail.com=0A=
> Fixes: 3951e7f050ac ("btrfs: add xxhash64 to checksumming algorithms")=0A=
> =0A=
> For information about bisection process see: https://goo.gl/tpsmEJ#bisect=
ion=0A=
> =0A=
=0A=
This commit only allowed 8 byte checksums, but d5178578bcd4 ("btrfs: direct=
ly=0A=
call into crypto framework for checksumming") is the one that was missing t=
he=0A=
conversion in btree_readpage_end_io_hook() and a prerequisite for 3951e7f05=
0ac=0A=
("btrfs: add xxhash64 to checksumming algorithms"). So I think it makes mor=
e =0A=
sense to add d5178578bcd4 to the fixes line.=0A=