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

syzbot
2018-04-23T10:10:13Z

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)

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+e073e4740cfbb3ae200b@syzkaller.appspotmail.com
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)

---
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See https://goo.gl/tpsmEJ for details.
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