syzbot

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conntrack cleanup blocked for 60s
WARNING: net/netfilter/nf_conntrack_core.c:2512 at nf_conntrack_cleanup_net_list+0x234/0x340 net/netfilter/nf_conntrack_core.c:2511, CPU#0: kworker/u8:3/22008
Modules linked in:
CPU: 0 UID: 0 PID: 22008 Comm: kworker/u8:3 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: netns cleanup_net
RIP: 0010:nf_conntrack_cleanup_net_list+0x234/0x340 net/netfilter/nf_conntrack_core.c:2511
Code: 08 48 89 df e8 ad 04 66 f8 4c 8b 3b 49 39 df 74 69 e8 d0 bc fb f7 45 31 e4 e9 8e fe ff ff e8 c3 bc fb f7 48 8d 3d fc d2 56 06 <67> 48 0f b9 3a eb c0 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c cd fe ff
RSP: 0018:ffffc9000d5f78d0 EFLAGS: 00010293
RAX: ffffffff89c9e0ed RBX: ffffc9000d5f7a70 RCX: ffff888077810000
RDX: 0000000000000000 RSI: fffffffffffffffe RDI: ffffffff9020b3f0
RBP: 0000000000000001 R08: ffff888054f5bc03 R09: 1ffff1100a9eb780
R10: dffffc0000000000 R11: ffffed100a9eb781 R12: 0000000000000001
R13: dffffc0000000000 R14: 0000000100016e8c R15: 0000000100016e8e
FS:  0000000000000000(0000) GS:ffff888125463000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f728562b000 CR3: 0000000073f89000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ops_exit_list net/core/net_namespace.c:205 [inline]
 ops_undo_list+0x52b/0x940 net/core/net_namespace.c:252
 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	08 48 89             	or     %cl,-0x77(%rax)
   3:	df e8                	fucomip %st(0),%st
   5:	ad                   	lods   %ds:(%rsi),%eax
   6:	04 66                	add    $0x66,%al
   8:	f8                   	clc
   9:	4c 8b 3b             	mov    (%rbx),%r15
   c:	49 39 df             	cmp    %rbx,%r15
   f:	74 69                	je     0x7a
  11:	e8 d0 bc fb f7       	call   0xf7fbbce6
  16:	45 31 e4             	xor    %r12d,%r12d
  19:	e9 8e fe ff ff       	jmp    0xfffffeac
  1e:	e8 c3 bc fb f7       	call   0xf7fbbce6
  23:	48 8d 3d fc d2 56 06 	lea    0x656d2fc(%rip),%rdi        # 0x656d326
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	eb c0                	jmp    0xfffffff1
  31:	89 e9                	mov    %ebp,%ecx
  33:	80 e1 07             	and    $0x7,%cl
  36:	80 c1 03             	add    $0x3,%cl
  39:	38 c1                	cmp    %al,%cl
  3b:	0f                   	.byte 0xf
  3c:	8c cd                	mov    %cs,%ebp
  3e:	fe                   	(bad)
  3f:	ff                   	.byte 0xff