kernel panic: stack is corrupted in validate_chain

kernel panic: stack is corrupted in validate_chain

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    249155c2 Merge branch 'parisc-5.2-4' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12a4572da00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9a31528e58cc12e2
dashboard link: https://syzkaller.appspot.com/bug?extid=6ba34346b252f2d497c7
compiler:       clang version 9.0.0 (/home/glider/llvm/clang  
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=135e34eea00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+6ba34346b252f2d497c7@syzkaller.appspotmail.com

Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in:  
validate_chain+0x69fc/0x84f0 kernel/locking/lockdep.c:161
CPU: 0 PID: 8300 Comm: syz-executor.4 Not tainted 5.2.0-rc6+ #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..


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Re: kernel panic: stack is corrupted in validate_chain

[syzbot]

syzbot has bisected this bug to:

commit e9db4ef6bf4ca9894bb324c76e01b8f1a16b2650
Author: John Fastabend <john.fastabend@gmail.com>
Date:   Sat Jun 30 13:17:47 2018 +0000

     bpf: sockhash fix omitted bucket lock in sock_close

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=11d4e129a00000
start commit:   249155c2 Merge branch 'parisc-5.2-4' of git://git.kernel.o..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=13d4e129a00000
console output: https://syzkaller.appspot.com/x/log.txt?x=15d4e129a00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9a31528e58cc12e2
dashboard link: https://syzkaller.appspot.com/bug?extid=6ba34346b252f2d497c7
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=135e34eea00000

Reported-by: syzbot+6ba34346b252f2d497c7@syzkaller.appspotmail.com
Fixes: e9db4ef6bf4c ("bpf: sockhash fix omitted bucket lock in sock_close")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection