syzbot


WARNING in xfrm6_tunnel_net_exit

Status: premoderation: reported syz repro on 2026/01/21 06:13
Bug presence: origin:downstream
[Documentation on labels]
Reported-by: syzbot+e1732515a139c4a501f1@syzkaller.appspotmail.com
First crash: 21d, last: 1h56m
Bug presence (3)
Date Name Commit Repro Result
2026/02/01 android16-6.12 (ToT) c13babfee861 syz [report] WARNING in xfrm6_tunnel_net_exit
2026/02/01 lts (merge base) 0bf1a02494c7 syz Didn't crash
2026/02/01 upstream (ToT) 162b42445b58 syz Failed due to an error; will retry later
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in xfrm6_tunnel_net_exit (2) net -1 C 48816 2543d 2825d 11/29 fixed on 2019/03/06 07:43
upstream WARNING in xfrm6_tunnel_net_exit net -1 syz 14002 2829d 2959d 5/29 fixed on 2018/05/17 10:02
upstream WARNING in xfrm6_tunnel_net_exit (4) net -1 syz done inconclusive 25810 69d 121d 0/29 upstream: reported syz repro on 2025/10/12 21:35
linux-4.19 WARNING in xfrm6_tunnel_net_exit -1 syz done 34 2250d 2498d 1/1 fixed on 2020/01/14 19:04

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 358 at net/ipv6/xfrm6_tunnel.c:341 xfrm6_tunnel_net_exit+0xc4/0x140 net/ipv6/xfrm6_tunnel.c:341
Modules linked in:
CPU: 0 UID: 0 PID: 358 Comm: kworker/u8:4 Not tainted syzkaller #0 e538f3f6a543b135812147031d083fd1f2699041
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: netns cleanup_net
RIP: 0010:xfrm6_tunnel_net_exit+0xc4/0x140 net/ipv6/xfrm6_tunnel.c:341
Code: e8 21 3e db fc 4b 83 3c 3e 00 75 19 e8 c5 72 83 fc 49 81 ff f8 07 00 00 74 1b e8 b7 72 83 fc 49 83 c7 08 eb c9 e8 ac 72 83 fc <0f> 0b 49 81 ff f8 07 00 00 75 e5 49 8d 9e 00 08 00 00 45 31 ff 4a
RSP: 0018:ffffc90001abfb90 EFLAGS: 00010293
RAX: ffffffff85042a64 RBX: ffff8881103811c0 RCX: ffff888107b19300
RDX: 0000000000000000 RSI: 0000000000c00000 RDI: ffff888114be0000
RBP: ffffc90001abfbb0 R08: ffffffff87d35187 R09: 1ffffffff0fa6a30
R10: dffffc0000000000 R11: fffffbfff0fa6a31 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888114be0000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efca48708c0 CR3: 0000000102f66000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 ops_exit_list net/core/net_namespace.c:173 [inline]
 cleanup_net+0x6bd/0xc90 net/core/net_namespace.c:642
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 358 at net/ipv6/xfrm6_tunnel.c:344 xfrm6_tunnel_net_exit+0x119/0x140 net/ipv6/xfrm6_tunnel.c:344
Modules linked in:
CPU: 0 UID: 0 PID: 358 Comm: kworker/u8:4 Tainted: G        W          syzkaller #0 e538f3f6a543b135812147031d083fd1f2699041
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: netns cleanup_net
RIP: 0010:xfrm6_tunnel_net_exit+0x119/0x140 net/ipv6/xfrm6_tunnel.c:344
Code: fc 4b 83 bc 3e 00 08 00 00 00 75 19 e8 70 72 83 fc 49 81 ff f8 07 00 00 74 1b e8 62 72 83 fc 49 83 c7 08 eb c5 e8 57 72 83 fc <0f> 0b 49 81 ff f8 07 00 00 75 e5 e8 47 72 83 fc 5b 41 5c 41 5e 41
RSP: 0018:ffffc90001abfb90 EFLAGS: 00010293
RAX: ffffffff85042ab9 RBX: ffff888114be0800 RCX: ffff888107b19300
RDX: 0000000000000000 RSI: 0000000000c00000 RDI: ffff888114be0808
RBP: ffffc90001abfbb0 R08: ffffffff87d35187 R09: 1ffffffff0fa6a30
R10: dffffc0000000000 R11: fffffbfff0fa6a31 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888114be0000 R15: 0000000000000008
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0073e4000 CR3: 000000012f182000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 ops_exit_list net/core/net_namespace.c:173 [inline]
 cleanup_net+0x6bd/0xc90 net/core/net_namespace.c:642
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 358 at net/xfrm/xfrm_state.c:3215 xfrm_state_fini+0x2be/0x310 net/xfrm/xfrm_state.c:3215
Modules linked in:
CPU: 0 UID: 0 PID: 358 Comm: kworker/u8:4 Tainted: G        W          syzkaller #0 e538f3f6a543b135812147031d083fd1f2699041
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: netns cleanup_net
RIP: 0010:xfrm_state_fini+0x2be/0x310 net/xfrm/xfrm_state.c:3215
Code: 3c 20 00 74 08 48 89 df e8 5f 07 f6 fc 48 8b 3b e8 f7 45 e1 fc 5b 41 5c 41 5d 41 5e 41 5f 5d e9 08 af b7 00 cc e8 f2 3b 9e fc <0f> 0b e9 b0 fd ff ff e8 e6 3b 9e fc 0f 0b e9 18 fe ff ff e8 da 3b
RSP: 0018:ffffc90001abfb70 EFLAGS: 00010293
RAX: ffffffff84e9611e RBX: ffff8881103811c0 RCX: ffff888107b19300
RDX: 0000000000000000 RSI: 0000000000c00000 RDI: ffff888107b19300
RBP: ffffc90001abfb98 R08: ffffffff87d35187 R09: 1ffffffff0fa6a30
R10: dffffc0000000000 R11: fffffbfff0fa6a31 R12: 1ffffffff0fa6780
R13: dffffc0000000000 R14: ffff888110381dc0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3146b48060 CR3: 0000000128136000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 xfrm_net_exit+0x31/0x80 net/xfrm/xfrm_policy.c:4342
 ops_exit_list net/core/net_namespace.c:173 [inline]
 cleanup_net+0x6bd/0xc90 net/core/net_namespace.c:642
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
---[ end trace 0000000000000000 ]---
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state

Crashes (1907):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/07 12:39 android16-6.12 6aeca23b5dee f20fc9f9 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/05 14:39 android16-6.12 c895831740a4 4936e85c .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/01 03:30 android16-6.12 c13babfee861 6b8752f2 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/11 09:49 android16-6.12 c9f98ae7122b 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/11 08:45 android16-6.12 c9f98ae7122b 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/11 07:54 android16-6.12 c9f98ae7122b 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/11 06:24 android16-6.12 c9f98ae7122b 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/11 04:39 android16-6.12 c9f98ae7122b 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/11 03:38 android16-6.12 c9f98ae7122b 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/11 02:40 android16-6.12 c9f98ae7122b 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/11 01:39 android16-6.12 c9f98ae7122b 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/11 01:31 android16-6.12 c9f98ae7122b 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 21:55 android16-6.12 99de7ab9a260 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 20:29 android16-6.12 99de7ab9a260 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 19:28 android16-6.12 99de7ab9a260 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 18:46 android16-6.12 99de7ab9a260 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 17:46 android16-6.12 99de7ab9a260 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 16:34 android16-6.12 99de7ab9a260 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 15:28 android16-6.12 99de7ab9a260 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 14:49 android16-6.12 99de7ab9a260 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 13:16 android16-6.12 99de7ab9a260 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 11:57 android16-6.12 99de7ab9a260 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 10:50 android16-6.12 99de7ab9a260 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 10:22 android16-6.12 99de7ab9a260 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 09:07 android16-6.12 99de7ab9a260 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 07:48 android16-6.12 3b54985e1263 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 06:46 android16-6.12 3b54985e1263 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 06:08 android16-6.12 3b54985e1263 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 04:37 android16-6.12 3b54985e1263 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 03:27 android16-6.12 3b54985e1263 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 02:24 android16-6.12 3b54985e1263 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 01:16 android16-6.12 3b54985e1263 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/10 00:26 android16-6.12 3b54985e1263 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 23:15 android16-6.12 3b54985e1263 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 22:03 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 20:36 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 19:14 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 18:06 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 17:02 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 15:46 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 14:51 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 13:46 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 12:44 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 11:42 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 10:54 android16-6.12 3b54985e1263 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
2026/02/09 09:33 android16-6.12 6aeca23b5dee 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in xfrm6_tunnel_net_exit
* Struck through repros no longer work on HEAD.