syzbot has bisected this bug to:
commit ab92d68fc22f9afab480153bd82a20f6e2533769
Author: Taehee Yoo <ap420073 at gmail.com>
Date: Mon Oct 21 18:47:51 2019 +0000
net: core: add generic lockdep keys
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12d37cb6e00000
start commit: 938f49c8 Add linux-next specific files for 20191211
git tree: linux-next
final crash: https://syzkaller.appspot.com/x/report.txt?x=11d37cb6e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=16d37cb6e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=96834c884ba7bb81
dashboard link: https://syzkaller.appspot.com/bug?extid=31043da7725b6ec210f1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12dc83dae00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ac8396e00000
Reported-by: syzbot+31043da7725b6ec210f1 at syzkaller.appspotmail.com
Fixes: ab92d68fc22f ("net: core: add generic lockdep keys")
For information about bisection process see: https://goo.gl/tpsmEJ#bisection