[v6.6] WARNING in __dev_queue_xmit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d27334b2888c Linux 6.6.151
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1794ba79580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0bc3d90c30838b5
dashboard link: https://syzkaller.appspot.com/bug?extid=701b41e82543d8d51a3c
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/695139abd971/disk-d27334b2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b11fc121442a/vmlinux-d27334b2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e226f54f9286/bzImage-d27334b2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+701b41...@syzkaller.appspotmail.com

------------[ cut here ]------------
skb_assert_len
WARNING: CPU: 0 PID: 17448 at include/linux/skbuff.h:2597 skb_assert_len include/linux/skbuff.h:2597 [inline]
WARNING: CPU: 0 PID: 17448 at include/linux/skbuff.h:2597 __dev_queue_xmit+0x1ec3/0x3630 net/core/dev.c:4367
Modules linked in:
CPU: 0 PID: 17448 Comm: syz.5.3642 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:ffffc9000c5b7640 EFLAGS: 00010246
RAX: 36337dc0f4368700 RBX: ffff888069a74570 RCX: 0000000000080000
RDX: ffffc9001a195000 RSI: 0000000000005b3d RDI: 0000000000005b3e
RBP: ffffc9000c5b7890 R08: ffffc9000c5b7247 R09: 1ffff920018b6e48
R10: dffffc0000000000 R11: fffff520018b6e49 R12: 1ffff1100d34e8a2
R13: 1ffff920018b6ee8 R14: 0000000000000000 R15: dffffc0000000000
FS: 00007f40273f76c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f52f6627dac CR3: 0000000069256000 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: 0033:0x7f402659e0d9
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:00007f40273f7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4026825fa0 RCX: 00007f402659e0d9
RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007f4026635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4026826038 R14: 00007f4026825fa0 R15: 00007ffd1f8000c8
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: d27334b2888c Linux 6.6.151
git tree: linux-6.6.y

console output: https://syzkaller.appspot.com/x/log.txt?x=10e7b6c6580000

kernel config: https://syzkaller.appspot.com/x/.config?x=f0bc3d90c30838b5
dashboard link: https://syzkaller.appspot.com/bug?extid=701b41e82543d8d51a3c
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11496679580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=127fe679580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/695139abd971/disk-d27334b2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b11fc121442a/vmlinux-d27334b2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e226f54f9286/bzImage-d27334b2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+701b41...@syzkaller.appspotmail.com

------------[ 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>


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.