Re: possible deadlock in console_unlock

[syzbot]

syzbot has bisected this bug to:

commit b6da31b2c07c46f2dcad1d86caa835227a16d9ff
Author: DaeRyong Jeong <threeearcat@xxxxxxxxx>
Date:   Mon Apr 30 15:27:04 2018 +0000

    tty: Fix data race in tty_insert_flip_string_fixed_flag

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=12d9bc0ee00000
start commit:   0ad39cb3 Merge tag 'kconfig-v4.18' of git://git.kernel.org..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=11d9bc0ee00000
console output: https://syzkaller.appspot.com/x/log.txt?x=16d9bc0ee00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b9a1f3aa8b8ddd16
dashboard link: https://syzkaller.appspot.com/bug?extid=43e93968b964e369db0b
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14c89b9f800000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=167f596f800000

Reported-by: syzbot+43e93968b964e369db0b@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: b6da31b2c07c ("tty: Fix data race in  
tty_insert_flip_string_fixed_flag")

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