Re: [syzbot] [mm?] INFO: rcu detected stall in sys_mprotect (8)

syzbot has bisected this issue to:

commit 5a781ccbd19e4664babcbe4b4ead7aa2b9283d22
Author: Vinicius Costa Gomes [off-list ref]
Date:   Sat Sep 29 00:59:43 2018 +0000

    tc: Add support for configuring the taprio scheduler

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=124e5a18580000
start commit:   31eae6d99587 selftests: drv-net: test drivers sleeping in ..
git tree:       net-next
final oops:     https://syzkaller.appspot.com/x/report.txt?x=114e5a18580000
console output: https://syzkaller.appspot.com/x/log.txt?x=164e5a18580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=289acde585746aad
dashboard link: https://syzkaller.appspot.com/bug?extid=6f7c31cf5ae4944ad6f0
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11d7270f980000

Reported-by: syzbot+6f7c31cf5ae4944ad6f0@syzkaller.appspotmail.com
Fixes: 5a781ccbd19e ("tc: Add support for configuring the taprio scheduler")

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