syzbot suspects this issue was fixed by commit:
commit 43016d02cf6e46edfc4696452251d34bba0c0435
Author: Florian Westphal <fw@xxxxxxxxx>
Date: Mon May 3 11:51:15 2021 +0000
netfilter: arptables: use pernet ops struct during unregister
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11518847d00000
start commit: 4d41ead6 Merge tag 'block-5.9-2020-08-28' of git://git.ker..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=891ca5711a9f1650
dashboard link: https://syzkaller.appspot.com/bug?extid=f7204dcf3df4bb4ce42c
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17a1352e900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11fdaf41900000
If the result looks correct, please mark the issue as fixed by replying with:
#syz fix: netfilter: arptables: use pernet ops struct during unregister
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
