syzbot has bisected this bug to:
commit 669de8bda87b92ab9a2fc663b3f5743c2ad1ae9f
Author: Bart Van Assche <bvanassche@xxxxxxx>
Date: Thu Feb 14 23:00:54 2019 +0000
kernel/workqueue: Use dynamic lockdep keys for workqueues
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17dec757200000
start commit: 669de8bd kernel/workqueue: Use dynamic lockdep keys for wo..
git tree: upstream
final crash: https://syzkaller.appspot.com/x/report.txt?x=143ec757200000
console output: https://syzkaller.appspot.com/x/log.txt?x=103ec757200000
kernel config: https://syzkaller.appspot.com/x/.config?x=bd349f14600e1305
dashboard link: https://syzkaller.appspot.com/bug?extid=78923eea7cf44364f4fb
userspace arch: amd64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=149c858d200000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=111aee33200000
Reported-by: syzbot+78923eea7cf44364f4fb@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 669de8bd ("kernel/workqueue: Use dynamic lockdep keys for
workqueues")