------------[ cut here ]------------
hook not found, pf 3 num 0
WARNING: CPU: 1 PID: 238 at net/netfilter/core.c:480 __nf_unregister_net_hook+0x187/0x580 net/netfilter/core.c:480
Modules linked in:
CPU: 1 PID: 238 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+0x187/0x580 net/netfilter/core.c:480
Code: 89 f0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 d6 03 00 00 8b 53 1c 44 89 e6 48 c7 c7 40 38 c1 89 4c 89 04 24 e8 b1 2c 61 01 <0f> 0b 4c 8b 04 24 e9 ba 00 00 00 48 89 ea 48 c1 e2 04 49 8d 7c 10
RSP: 0018:ffffc9000153fbf0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8880221a0c00 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: fffff520002a7f70
RBP: 0000000000000000 R08: 0000000000000001 R09: ffff8880b9f1fa5b
R10: ffffed10173e3f4b R11: 0000000000000001 R12: 0000000000000003
R13: ffff8880186a8000 R14: ffff8880221a0c1c R15: ffff8880186a8f20
FS:  0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2034e0a000 CR3: 0000000011987000 CR4: 0000000000350ee0
Call Trace:
 nf_unregister_net_hook net/netfilter/core.c:502 [inline]
 nf_unregister_net_hooks+0xb1/0xf0 net/netfilter/core.c:576
 ops_pre_exit_list net/core/net_namespace.c:165 [inline]
 cleanup_net+0x3a4/0x990 net/core/net_namespace.c:583
 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2275
 worker_thread+0x598/0xf80 kernel/workqueue.c:2421
 kthread+0x36f/0x450 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294