Re: WARNING: kernel stack regs at (ptrval) in syzkaller has bad 'bp' value (ptrval)

From: Dmitry Vyukov
Date: Mon Apr 23 2018 - 07:00:00 EST


On Mon, Apr 23, 2018 at 12:10 PM, syzbot
<syzbot+e073e4740cfbb3ae200b@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> Hello,
>
> syzbot hit the following crash on upstream commit
> 5ec83b22a2dd13180762c89698e4e2c2881a423c (Sun Apr 22 19:13:04 2018 +0000)
> Merge tag '4.17-rc1-SMB3-CIFS' of git://git.samba.org/sfrench/cifs-2.6
> syzbot dashboard link:
> https://syzkaller.appspot.com/bug?extid=e073e4740cfbb3ae200b
>
> C reproducer: https://syzkaller.appspot.com/x/repro.c?id=6509307940044800
> syzkaller reproducer:
> https://syzkaller.appspot.com/x/repro.syz?id=6027105183727616
> Raw console output:
> https://syzkaller.appspot.com/x/log.txt?id=4763013630394368
> Kernel config:
> https://syzkaller.appspot.com/x/.config?id=1808800213120130118
> compiler: gcc (GCC) 8.0.1 20180413 (experimental)

There are 2 similar bugs reported:

https://syzkaller.appspot.com/bug?id=4fcc07e4e85fc6c1d5472fcc8ab5a35db01972dc
https://syzkaller.appspot.com/bug?id=bed7a7acabe08fe69a89a4225572911a32598651

They all seem to point to crypto/SHA3/K512_4.
+crypto maintainers

> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+e073e4740cfbb3ae200b@xxxxxxxxxxxxxxxxxxxxxxxxx
> It will help syzbot understand when the bug is fixed. See footer for
> details.
> If you forward the report, please keep this part and the footer.
>
> (ptrval): 0000000000445649 (0x445649)
> (ptrval): 0000000000000033 (0x33)
> (ptrval): 0000000000000216 (0x216)
> (ptrval): 00007f155536eda8 (0x7f155536eda8)
> (ptrval): 000000000000002b (0x2b)
> WARNING: kernel stack regs at (ptrval) in syzkaller547737:4493 has
> bad 'bp' value (ptrval)
> WARNING: kernel stack frame pointer at (ptrval) in
> syzkaller547737:4496 has bad value (ptrval)
>
>
> ---
> This bug is generated by a dumb bot. It may contain errors.
> See https://goo.gl/tpsmEJ for details.
> Direct all questions to syzkaller@xxxxxxxxxxxxxxxxx
>
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