------------[ cut here ]------------
hook not found, pf 3 num 0
WARNING: CPU: 0 PID: 321 at net/netfilter/core.c:480 __nf_unregister_net_hook+0x1eb/0x610 net/netfilter/core.c:480
Modules linked in:
CPU: 0 PID: 321 Comm: kworker/u4:4 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:__nf_unregister_net_hook+0x1eb/0x610 net/netfilter/core.c:480
Code: 0f b6 14 02 48 89 c8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 11 04 00 00 8b 53 1c 89 ee 48 c7 c7 c0 d8 6d 8a e8 70 4b 8a 01 <0f> 0b e9 e5 00 00 00 e8 89 17 2e fa 44 8b 3c 24 4c 89 f8 48 c1 e0
RSP: 0018:ffffc90001d1fbc0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff88814a027100 RCX: 0000000000000000
RDX: ffff8880159fb880 RSI: ffffffff815c8ba5 RDI: fffff520003a3f6a
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815c2a0e R11: 0000000000000000 R12: ffff88801a420f20
R13: 0000000000000000 R14: ffff88801ff01000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6100ba1000 CR3: 0000000026387000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 nf_unregister_net_hook net/netfilter/core.c:502 [inline]
 nf_unregister_net_hooks+0x117/0x160 net/netfilter/core.c:576
 arpt_unregister_table_pre_exit+0x67/0x80 net/ipv4/netfilter/arp_tables.c:1565
 ops_pre_exit_list net/core/net_namespace.c:165 [inline]
 cleanup_net+0x451/0xb10 net/core/net_namespace.c:583
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294