[syzbot] [can?] WARNING in __netif_receive_skb_core

[syzbot <syzbot+1aae11dc8d42ec1a87ec@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    704340f1cd0d Merge tag 'x86_urgent_for_7.3-rc4' of git://g..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=15a62471580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f
dashboard link: https://syzkaller.appspot.com/bug?extid=1aae11dc8d42ec1a87ec
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1580bc8e580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=169f9905580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/192c594c6096/disk-704340f1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/79d1488deb4b/vmlinux-704340f1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fd108c2b8ca0/bzImage-704340f1.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1aae11dc8d42ec1a87ec@syzkaller.appspotmail.com

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1
WARNING: ./include/linux/skbuff.h:3003 at skb_reset_mac_len include/linux/skbuff.h:3003 [inline], CPU#0: kworker/u8:1/13
WARNING: ./include/linux/skbuff.h:3003 at __netif_receive_skb_core.constprop.0+0x1706/0x3530 net/core/dev.c:6061, CPU#0: kworker/u8:1/13
Modules linked in:
CPU: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Workqueue: events_unbound flush_to_ldisc
RIP: 0010:skb_reset_mac_len include/linux/skbuff.h:3003 [inline]
RIP: 0010:__netif_receive_skb_core.constprop.0+0x1706/0x3530 net/core/dev.c:6061
Code: de 4c 8b bc 24 e8 00 00 00 e8 86 f7 6b f8 85 db 0f 88 11 f2 ff ff 31 db 4d 8d af 81 00 00 00 e9 01 ed ff ff e8 fb fc 6b f8 90 <0f> 0b 90 31 db e9 43 eb ff ff e8 eb fc 6b f8 e8 66 af 4f f8 31 ff
RSP: 0018:ffffc90000007990 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000040 RCX: 0000000000000101
RDX: ffff88801f2a0000 RSI: ffffffff89a02015 RDI: ffff88801f2a0000
RBP: 000000000000ffff R08: 0000000000000003 R09: 000000000000ffff
R10: 000000000000ffff R11: 0000000000000001 R12: ffff888075f88140
R13: ffffc90000007c10 R14: ffff888075f88140 R15: ffff888075f88140
FS:  0000000000000000(0000) GS:ffff888123b59000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd21e26870 CR3: 00000000729f5000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6262
 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6377
 process_backlog+0x487/0x1600 net/core/dev.c:6728
 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7787
 napi_poll net/core/dev.c:7850 [inline]
 net_rx_action+0xa40/0xf20 net/core/dev.c:8007
 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
 do_softirq kernel/softirq.c:546 [inline]
 do_softirq+0xaf/0xf0 kernel/softirq.c:533
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xff/0x120 kernel/softirq.c:473
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 netif_rx net/core/dev.c:5837 [inline]
 netif_rx+0x93/0xb0 net/core/dev.c:5826
 slcan_bump_err drivers/net/can/slcan/slcan-core.c:448 [inline]
 slcan_bump drivers/net/can/slcan/slcan-core.c:463 [inline]
 slcan_unesc drivers/net/can/slcan/slcan-core.c:476 [inline]
 slcan_receive_buf+0x1a66/0x1f30 drivers/net/can/slcan/slcan-core.c:807
 tty_ldisc_receive_buf+0x15a/0x1a0 drivers/tty/tty_buffer.c:398
 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:452 [inline]
 flush_to_ldisc+0x26b/0x730 drivers/tty/tty_buffer.c:502
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>


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