WARNING in __dev_queue_xmit

Status: upstream: reported C repro on 2026/08/17 21:29
Reported-by: syzbot+701b41e82543d8d51a3c@syzkaller.appspotmail.com
First crash: 1d08h, last: 4h44m
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 WARNING in __dev_queue_xmit origin:lts -1 syz, C 21 1d00h 11d 0/1 premoderation: reported C repro on 2026/08/08 00:18
upstream WARNING in __dev_queue_xmit (3) net -1 syz, C error inconclusive 20 1137d 1160d 0/29 auto-obsoleted due to no activity on 2023/11/09 02:33
linux-5.15 WARNING in __dev_queue_xmit -1 syz, C 107 672d 756d 0/3 auto-obsoleted due to no activity on 2024/12/25 04:54
upstream WARNING in __dev_queue_xmit (6) net prio:low -1 syz, C error 35 14h03m 8d14h 22/29 upstream: reported C repro on 2026/08/10 15:02
upstream WARNING in __dev_queue_xmit (4) net -1 syz, C 387 667d 713d 28/29 fixed on 2024/10/22 11:57
upstream WARNING in __dev_queue_xmit -1 syz, C done 16774 1271d 1485d 22/29 fixed on 2023/02/24 14:17
upstream WARNING in __dev_queue_xmit (2) net -1 syz, C 76 1199d 1271d 22/29 fixed on 2023/06/08 14:41
upstream WARNING in __dev_queue_xmit (5) net -1 syz, C 41 611d 609d 28/29 fixed on 2025/05/06 15:33
linux-6.1 WARNING in __dev_queue_xmit (2) -1 syz, C 38 1h10m 11d 0/3 upstream: reported C repro on 2026/08/08 00:39
linux-6.1 WARNING in __dev_queue_xmit -1 43 672d 772d 0/3 auto-obsoleted due to no activity on 2024/12/25 04:13

Sample crash report:
------------[ cut here ]------------
skb_assert_len
WARNING: CPU: 0 PID: 5927 at include/linux/skbuff.h:2597 skb_assert_len include/linux/skbuff.h:2597 [inline]
WARNING: CPU: 0 PID: 5927 at include/linux/skbuff.h:2597 __dev_queue_xmit+0x1ec3/0x3630 net/core/dev.c:4367
Modules linked in:
CPU: 0 PID: 5927 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:skb_assert_len include/linux/skbuff.h:2597 [inline]
RIP: 0010:__dev_queue_xmit+0x1ec3/0x3630 net/core/dev.c:4367
Code: df 4c 8b 6c 24 28 e9 10 e7 ff ff e8 47 32 04 f9 c6 05 52 be f3 05 01 48 c7 c7 a0 68 c4 8b 48 c7 c6 b4 9e 9f 8c e8 3d ff cd f8 <0f> 0b 80 3d 37 be f3 05 01 0f 84 0f e3 ff ff e8 19 32 04 f9 c6 05
RSP: 0018:ffffc900033e7640 EFLAGS: 00010246
RAX: 0838c9bc9182fd00 RBX: ffff888072e0d430 RCX: ffff888025a5da00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900033e7890 R08: ffff8880b8e28c53 R09: 1ffff110171c518a
R10: dffffc0000000000 R11: ffffed10171c518b R12: 1ffff1100e5c1a7a
R13: 1ffff9200067cee8 R14: 0000000000000000 R15: dffffc0000000000
FS:  00005555689b6500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000200 CR3: 000000007b919000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 tpacket_snd net/packet/af_packet.c:2945 [inline]
 packet_sendmsg+0x28fe/0x4c70 net/packet/af_packet.c:3172
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 sock_write_iter+0x2dc/0x420 net/socket.c:1161
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7764f9e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffbe02b8c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7765225fa0 RCX: 00007f7764f9e0d9
RDX: 0000000000000002 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007f7765035024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7765225fac R14: 00007f7765225fa0 R15: 00007f7765225fa0
 </TASK>

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/18 07:20 linux-6.6.y d27334b2888c 1e72964b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/19 00:58 linux-6.6.y d27334b2888c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/19 00:55 linux-6.6.y d27334b2888c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/18 20:42 linux-6.6.y d27334b2888c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/18 20:41 linux-6.6.y d27334b2888c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/18 20:23 linux-6.6.y d27334b2888c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/18 20:23 linux-6.6.y d27334b2888c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/18 07:25 linux-6.6.y d27334b2888c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/18 03:43 linux-6.6.y d27334b2888c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/17 21:32 linux-6.6.y d27334b2888c 905244d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/17 21:32 linux-6.6.y d27334b2888c 905244d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/17 21:29 linux-6.6.y d27334b2888c 905244d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
2026/08/17 21:29 linux-6.6.y d27334b2888c 905244d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __dev_queue_xmit
* Struck through repros no longer work on HEAD.