WARNING in nf_conntrack_cleanup_net

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision	Error
5c37299a-ac88-4bd7-8bef-ce8ff9942e6d	assessment-security	DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌	❓	WARNING in nf_conntrack_cleanup_net_list (2)	2026/05/29 23:15	2026/05/29 23:15	2026/05/29 23:51	6b4a844333e83556da95d61d7f207e7ef5cd4bc6

Title	Replies (including bot)	Last reply
[syzbot] [netfilter?] WARNING in nf_conntrack_cleanup_net_list (2)	0 (1)	2026/05/29 20:02

Title

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[syzbot] [netfilter?] WARNING in nf_conntrack_cleanup_net_list (2)

0 (1)

2026/05/29 20:02

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	WARNING in nf_conntrack_cleanup_net_list netfilter	-1				765	36d	170d	29/29	fixed on 2026/05/06 16:40

Rank 🛈

upstream

WARNING in nf_conntrack_cleanup_net_list netfilter

-1

765

36d

170d

29/29

fixed on 2026/05/06 16:40

------------[ cut here ]------------ conntrack cleanup blocked for 60s WARNING: net/netfilter/nf_conntrack_core.c:2506 at nf_conntrack_cleanup_net_list+0x4f7/0x690 net/netfilter/nf_conntrack_core.c:2506, CPU#2: kworker/u32:12/10858 Modules linked in: CPU: 2 UID: 0 PID: 10858 Comm: kworker/u32:12 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: netns cleanup_net RIP: 0010:nf_conntrack_cleanup_net_list+0x4f7/0x690 net/netfilter/nf_conntrack_core.c:2506 Code: 29 c3 48 89 de e8 a9 84 58 f8 48 85 db 78 0f e8 bf 89 58 f8 e8 ea 64 dc 01 e9 0e fc ff ff e8 b0 89 58 f8 48 8d 3d 39 7f 36 07 <67> 48 0f b9 3a eb de 4c 8b 6c 24 40 e8 98 89 58 f8 48 b8 00 00 00 RSP: 0018:ffffc90004057968 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffffffffffffffff RCX: ffffffff89b02597 RDX: ffff888042c5ca00 RSI: ffffffff89b025b0 RDI: ffffffff90e6a4f0 RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000001 R14: ffffc90004057b20 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880d656a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c360d0b CR3: 000000004064f000 CR4: 0000000000352ef0 DR0: 0000000000000009 DR1: 00000000000000c9 DR2: 00000000000000f3 DR3: 00000000000000c0 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: <TASK> ops_exit_list net/core/net_namespace.c:205 [inline] ops_undo_list+0x363/0xab0 net/core/net_namespace.c:252 cleanup_net+0x499/0x920 net/core/net_namespace.c:702 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: 29 c3 sub %eax,%ebx 2: 48 89 de mov %rbx,%rsi 5: e8 a9 84 58 f8 call 0xf85884b3 a: 48 85 db test %rbx,%rbx d: 78 0f js 0x1e f: e8 bf 89 58 f8 call 0xf85889d3 14: e8 ea 64 dc 01 call 0x1dc6503 19: e9 0e fc ff ff jmp 0xfffffc2c 1e: e8 b0 89 58 f8 call 0xf85889d3 23: 48 8d 3d 39 7f 36 07 lea 0x7367f39(%rip),%rdi # 0x7367f63 * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: eb de jmp 0xf 31: 4c 8b 6c 24 40 mov 0x40(%rsp),%r13 36: e8 98 89 58 f8 call 0xf85889d3 3b: 48 rex.W 3c: b8 .byte 0xb8 3d: 00 00 add %al,(%rax)

Crashes (1):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2026/05/27 09:38	upstream	d60ec36cab33	2b01f00e	.config	console log	report			info	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	WARNING in nf_conntrack_cleanup_net_list

Crashes (1):

Assets (help?)