Re: WARNING in cgroup_apply_control_enable

[syzbot]

syzbot has bisected this bug to:

commit 0d5936344f30aba0f6ddb92b030cb6a05168efe6
Author: Tejun Heo <tj@xxxxxxxxxx>
Date:   Mon Sep 25 16:00:19 2017 +0000

    sched: Implement interface for cgroup unified hierarchy

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16142bd2e00000
start commit:   3a272031 Merge tag 'libnvdimm-fixes-4.19-rc8' of git://git..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=15142bd2e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=11142bd2e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=88e9a8a39dc0be2d
dashboard link: https://syzkaller.appspot.com/bug?extid=5493b2a54d31d6aea629
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11c890f6400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10a94dd6400000

Reported-by: syzbot+5493b2a54d31d6aea629@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 0d5936344f30 ("sched: Implement interface for cgroup unified  
hierarchy")

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