syzbot


WARNING in nf_conntrack_cleanup_net_list

Status: upstream: reported on 2025/12/11 18:38
Subsystems: netfilter
[Documentation on labels]
Reported-by: syzbot+4393c47753b7808dac7d@syzkaller.appspotmail.com
Fix commit: 2ef02ac38d3c inet: frags: drop fraglist conntrack references
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-gce-arm64 ci2-upstream-usb]
First crash: 35d, last: 10h21m
Discussions (2)
Title Replies (including bot) Last reply
[PATCH net] inet: frags: drop fraglist conntrack references 3 (3) 2026/01/04 20:13
[syzbot] [netfilter?] WARNING in nf_conntrack_cleanup_net_list 6 (7) 2025/12/13 18:54

Sample crash report:
------------[ cut here ]------------
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/u8:3/37
Modules linked in:
CPU: 0 UID: 0 PID: 37 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 10/25/2025
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 8d 49 a4 f8 4c 8b 3b 49 39 df 74 69 e8 90 26 3e f8 45 31 e4 e9 8e fe ff ff e8 83 26 3e f8 48 8d 3d 4c f9 0d 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:ffffc90000ad7870 EFLAGS: 00010293
RAX: ffffffff8982d22d RBX: ffffc90000ad7a00 RCX: ffff888141683d00
RDX: 0000000000000000 RSI: fffffffffffffffe RDI: ffffffff8f90cb80
RBP: 0000000000000001 R08: ffff888056985c03 R09: 1ffff1100ad30b80
R10: dffffc0000000000 R11: ffffed100ad30b81 R12: 0000000000000001
R13: dffffc0000000000 R14: 0000000100016fa9 R15: 0000000100016fab
FS:  0000000000000000(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f08e00caf98 CR3: 0000000052356000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ops_exit_list net/core/net_namespace.c:205 [inline]
 ops_undo_list+0x525/0x990 net/core/net_namespace.c:252
 cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
----------------
Code disassembly (best guess):
   0:	08 48 89             	or     %cl,-0x77(%rax)
   3:	df e8                	fucomip %st(0),%st
   5:	8d 49 a4             	lea    -0x5c(%rcx),%ecx
   8:	f8                   	clc
   9:	4c 8b 3b             	mov    (%rbx),%r15
   c:	49 39 df             	cmp    %rbx,%r15
   f:	74 69                	je     0x7a
  11:	e8 90 26 3e f8       	call   0xf83e26a6
  16:	45 31 e4             	xor    %r12d,%r12d
  19:	e9 8e fe ff ff       	jmp    0xfffffeac
  1e:	e8 83 26 3e f8       	call   0xf83e26a6
  23:	48 8d 3d 4c f9 0d 06 	lea    0x60df94c(%rip),%rdi        # 0x60df976
* 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

Crashes (281):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/15 11:31 upstream 944aacb68baf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/15 09:34 upstream 944aacb68baf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/15 07:48 upstream 944aacb68baf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in nf_conntrack_cleanup_net_list
2026/01/15 04:59 upstream 944aacb68baf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in nf_conntrack_cleanup_net_list
2026/01/15 02:20 upstream 944aacb68baf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in nf_conntrack_cleanup_net_list
2026/01/14 05:55 upstream b54345928fa1 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in nf_conntrack_cleanup_net_list
2026/01/14 00:44 upstream b54345928fa1 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in nf_conntrack_cleanup_net_list
2026/01/13 23:31 upstream b54345928fa1 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in nf_conntrack_cleanup_net_list
2026/01/13 14:47 upstream b71e635feefc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/13 11:56 upstream b71e635feefc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in nf_conntrack_cleanup_net_list
2026/01/13 05:43 upstream 0f61b1860cc3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in nf_conntrack_cleanup_net_list
2026/01/12 08:34 upstream 7143203341dc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/12 06:27 upstream 0f61b1860cc3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in nf_conntrack_cleanup_net_list
2026/01/11 21:29 upstream 755bc1335e3b d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/11 09:36 upstream 97313d6113ab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/11 08:20 upstream 0fa27899e014 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in nf_conntrack_cleanup_net_list
2026/01/11 04:14 upstream 97313d6113ab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in nf_conntrack_cleanup_net_list
2026/01/09 16:09 upstream 623fb9912f6a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/09 04:25 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/08 18:11 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in nf_conntrack_cleanup_net_list
2026/01/08 15:37 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in nf_conntrack_cleanup_net_list
2026/01/08 06:25 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/08 05:12 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/07 20:16 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in nf_conntrack_cleanup_net_list
2026/01/07 15:13 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/07 14:02 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/07 09:00 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/14 14:27 upstream c537e12daeec d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in nf_conntrack_cleanup_net_list
2026/01/15 01:17 upstream 944aacb68baf d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/14 22:10 upstream 944aacb68baf d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/14 16:35 upstream c537e12daeec d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/14 10:13 upstream c537e12daeec d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/12 11:48 upstream 9c7ef209cd0f d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/12 10:27 upstream 9c7ef209cd0f d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/11 02:39 upstream 97313d6113ab d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/11 00:36 upstream 97313d6113ab d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/10 01:02 upstream 372800cb95a3 d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/09 09:31 upstream 623fb9912f6a d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/08 08:13 upstream f0b9d8eb98df d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in nf_conntrack_cleanup_net_list
2026/01/11 19:55 upstream 755bc1335e3b d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in nf_conntrack_cleanup_net_list
2026/01/10 11:13 upstream b6151c4e60e5 d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in nf_conntrack_cleanup_net_list
2026/01/08 09:47 upstream f0b9d8eb98df d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in nf_conntrack_cleanup_net_list
2026/01/07 12:42 upstream f0b9d8eb98df d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in nf_conntrack_cleanup_net_list
2026/01/08 13:24 net 6abcf751bc08 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/15 14:47 net-next cc75d43783f7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/14 18:26 net-next 3b194343c250 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/13 21:24 net-next de746f8f5341 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/12 21:49 net-next 60d8484c4cec d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/09 11:24 net-next 59ba823e689f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in nf_conntrack_cleanup_net_list
2026/01/15 03:33 linux-next b775e489bec7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in nf_conntrack_cleanup_net_list
2026/01/12 23:48 linux-next f417b7ffcbef d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in nf_conntrack_cleanup_net_list
2026/01/07 10:10 linux-next f96074c6d01d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in nf_conntrack_cleanup_net_list
2025/12/11 05:14 linux-next 5ce74bc1b7cb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in nf_conntrack_cleanup_net_list
* Struck through repros no longer work on HEAD.