Re: possible deadlock in flush_workqueue (2)

syzbot has bisected this bug to:

commit f547fac624be53ad8b07e9ebca7654a7827ba61b
Author: Sabrina Dubroca [off-list ref]
Date:   Fri Oct 12 14:22:47 2018 +0000

     ipv6: rate-limit probes for neighbourless routes

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17affd1b200000
start commit:   f547fac6 ipv6: rate-limit probes for neighbourless routes
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=146ffd1b200000
console output: https://syzkaller.appspot.com/x/log.txt?x=106ffd1b200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=963b24abf3f7c2d8
dashboard link: https://syzkaller.appspot.com/bug?extid=a50c7541a4a55cd49b02
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12097f03400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10b55ac5400000

Reported-by: syzbot+a50c7541a4a55cd49b02@syzkaller.appspotmail.com
Fixes: f547fac624be ("ipv6: rate-limit probes for neighbourless routes")

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