syzbot has bisected this issue to:

commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
Author: Leon Romanovsky [off-list ref]
Date:   Thu Oct 21 14:16:14 2021 +0000

    devlink: Remove not-executed trap policer notifications

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16464095b00000
start commit:   158b515f703e tun: avoid double free in tun_free_netdev
git tree:       net
final oops:     https://syzkaller.appspot.com/x/report.txt?x=15464095b00000
console output: https://syzkaller.appspot.com/x/log.txt?x=11464095b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fa556098924b78f0
dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13ff127eb00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11bedb6db00000

Reported-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com
Fixes: 22849b5ea595 ("devlink: Remove not-executed trap policer notifications")

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