------------[ cut here ]------------ hook not found, pf 3 num 0 WARNING: CPU: 1 PID: 556 at net/netfilter/core.c:480 __nf_unregister_net_hook+0x17a/0x560 net/netfilter/core.c:480 Modules linked in: CPU: 1 PID: 556 Comm: kworker/u4:6 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+0x17a/0x560 net/netfilter/core.c:480 Code: 89 f0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 a7 03 00 00 8b 53 1c 44 89 e6 48 c7 c7 40 39 9d 89 4c 89 04 24 e8 d4 86 62 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:ffffc90002c0fbf0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88814715fc00 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000004 RDI: fffff52000581f70 RBP: 0000000000000001 R08: 0000000000000001 R09: ffff8880ba11fa5b R10: ffffed1017423f4b R11: 0000000000000001 R12: 0000000000000003 R13: ffff88802db70000 R14: ffff88814715fc1c R15: ffff88802db70f20 FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcabe4fd020 CR3: 0000000024dd9000 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+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/0x13b0 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