Re: possible deadlock in __static_key_slow_dec

[syzbot]

syzbot has bisected this bug to:

commit b9a1e627405d68d475a3c1f35e685ccfb5bbe668
Author: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Date:   Thu Jul 4 00:21:13 2019 +0000

    hsr: implement dellink to clean up resources

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1449a0b1e00000
start commit:   63623fd4 Merge tag 'for-linus' of git://git.kernel.org/pub..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=1649a0b1e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=1249a0b1e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5d2e033af114153f
dashboard link: https://syzkaller.appspot.com/bug?extid=61ffbb75d30176841f76
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14f0efa1e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=119cf3b5e00000

Reported-by: syzbot+61ffbb75d30176841f76@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: b9a1e627405d ("hsr: implement dellink to clean up resources")

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