Re: WARNING: refcount bug in igmp_start_timer

[syzbot]

syzbot has bisected this bug to:

commit fc5e9d63a8db40e9e3a3b180be33d44af8a3cee8
Author: Daniel Vetter <daniel.vetter@xxxxxxxx>
Date:   Wed May 24 14:52:05 2017 +0000

    drm/sti: Drop drm_vblank_cleanup

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=13f62c2d200000
start commit:   ae596de1 Compiler Attributes: naked can be shared
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=100e2c2d200000
console output: https://syzkaller.appspot.com/x/log.txt?x=17f62c2d200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5fa12be50bca08d8
dashboard link: https://syzkaller.appspot.com/bug?extid=e28037ac1c96d2a86e89
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=178537da400000

Reported-by: syzbot+e28037ac1c96d2a86e89@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: fc5e9d63a8db ("drm/sti: Drop drm_vblank_cleanup")

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