WARNING in ipip_tunnel_xmit

Status: closed as invalid on 2026/10/06 01:41
Subsystems: net
Labels: prio:low
[Documentation on labels]
First crash: 51d, last: 3d20h
Cause bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
a993dd8f assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ WARNING in ipip_tunnel_xmit 2026/08/19 02:09 2026/08/19 02:09 2026/08/19 02:59 1e72964b
▶ ▼ Last patch testing requests (3)
Created Duration User Patch Repo Result
2026/10/04 15:12 22m retest repro net report job log log
2026/09/10 00:27 13m retest repro upstream report job log log
2026/09/10 00:27 13m retest repro upstream report job log log
▶ ▼ Cause bisection attempts (2)
Created Duration User Patch Repo Result
2026/09/29 23:33 12h04m bisect net error job log
2026/09/20 16:39 0m bisect net error

Sample crash report:
------------[ cut here ]------------
len > ((int)(~0U >> 1))
WARNING: ./include/linux/skbuff.h:2864 at pskb_may_pull_reason include/linux/skbuff.h:2864 [inline], CPU#0: syz-executor218/5667
WARNING: ./include/linux/skbuff.h:2864 at pskb_network_may_pull_reason include/linux/skbuff.h:3294 [inline], CPU#0: syz-executor218/5667
WARNING: ./include/linux/skbuff.h:2864 at pskb_inet_may_pull_reason include/net/ip_tunnels.h:480 [inline], CPU#0: syz-executor218/5667
WARNING: ./include/linux/skbuff.h:2864 at pskb_inet_may_pull include/net/ip_tunnels.h:485 [inline], CPU#0: syz-executor218/5667
WARNING: ./include/linux/skbuff.h:2864 at ipip_tunnel_xmit+0x330/0x4c0 net/ipv4/ipip.c:289, CPU#0: syz-executor218/5667
Modules linked in:
CPU: 0 UID: 0 PID: 5667 Comm: syz-executor218 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:pskb_may_pull_reason include/linux/skbuff.h:2864 [inline]
RIP: 0010:pskb_network_may_pull_reason include/linux/skbuff.h:3294 [inline]
RIP: 0010:pskb_inet_may_pull_reason include/net/ip_tunnels.h:480 [inline]
RIP: 0010:pskb_inet_may_pull include/net/ip_tunnels.h:485 [inline]
RIP: 0010:ipip_tunnel_xmit+0x330/0x4c0 net/ipv4/ipip.c:289
Code: ff ff ff 4d 8d bd 4c 0f 00 00 e8 0b b8 5b f7 4c 89 f7 4c 89 ee 4c 89 fa 89 e9 e8 fb b5 fc ff e9 28 ff ff ff e8 f1 b7 5b f7 90 <0f> 0b 90 e9 cc fd ff ff 44 89 e7 44 89 fe e8 ed b9 5b f7 45 39 fc
RSP: 0018:ffffc90003d17298 EFLAGS: 00010293
RAX: ffffffff8a6c1a8f RBX: dffffc0000000000 RCX: ffff88807e749f40
RDX: 0000000000000000 RSI: 00000000ffffff40 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88807e749f40 R09: 0000000000000002
R10: 0000000000004888 R11: ffffffff8a6c1760 R12: 00000000ffffff40
R13: ffff888023708498 R14: ffff8880237083c0 R15: 0000000000000000
FS:  00007f132ab386c0(0000) GS:ffff888124cce000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000000c0 CR3: 0000000072606000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __netdev_start_xmit include/linux/netdevice.h:5429 [inline]
 netdev_start_xmit include/linux/netdevice.h:5438 [inline]
 __dev_direct_xmit+0x4b6/0x730 net/core/dev.c:4990
 __xsk_generic_xmit net/xdp/xsk.c:1280 [inline]
 xsk_generic_xmit+0x272b/0x4730 net/xdp/xsk.c:1336
 xsk_poll+0x326/0x670 net/xdp/xsk.c:1464
 sock_poll+0x338/0x3f0 net/socket.c:1514
 vfs_poll include/linux/poll.h:82 [inline]
 select_poll_one fs/select.c:480 [inline]
 do_select+0x1067/0x17f0 fs/select.c:536
 core_sys_select+0x86d/0xb40 fs/select.c:677
 do_pselect fs/select.c:770 [inline]
 __do_sys_pselect6 fs/select.c:809 [inline]
 __se_sys_pselect6+0x267/0x320 fs/select.c:800
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f132ab64069
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 d0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f132ab381c8 EFLAGS: 00000246 ORIG_RAX: 000000000000010e
RAX: ffffffffffffffda RBX: 00007f132ac15b88 RCX: 00007f132ab64069
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000040
RBP: 00007f132ac15b80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000040 R11: 0000000000000246 R12: 00007f132abe0028
R13: 0000200000000000 R14: 0000200000000450 R15: 0000200000000440
 </TASK>

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/20 14:11 net c82b797abe66 853b104b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ipip_tunnel_xmit
2026/08/18 18:25 upstream 0f23d56f17fd 1e72964b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in ipip_tunnel_xmit
2026/08/18 18:00 upstream 0f23d56f17fd 1e72964b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in ipip_tunnel_xmit
2026/08/27 00:03 upstream 818bebeb63dd a2b77b9e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in ipip_tunnel_xmit
2026/08/18 17:34 upstream 0f23d56f17fd 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in ipip_tunnel_xmit
2026/09/20 12:32 net c82b797abe66 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in ipip_tunnel_xmit
2026/10/05 16:51 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe98fb51bf62 1995e6c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in ipip_tunnel_xmit
* Struck through repros no longer work on HEAD.