[v5.15] WARNING in l2cap_chan_send

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9eec9a14ee10 Linux 5.15.198
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=133e8a5a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=307f5261162016128e88
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7146a7b4242e/disk-9eec9a14.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a11468b96c22/vmlinux-9eec9a14.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e7cb8f058e1c/bzImage-9eec9a14.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+307f52...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 8156 at kernel/workqueue.c:1453 __queue_work+0xc04/0xd50 kernel/workqueue.c:1453
Modules linked in:
CPU: 0 PID: 8156 Comm: kbnepd bnep0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__queue_work+0xc04/0xd50 kernel/workqueue.c:1453
Code: fc ff ff 48 8b 4c 24 08 80 e1 07 80 c1 03 38 c1 0f 8c 13 fd ff ff 48 8b 7c 24 08 e8 06 28 70 00 e9 04 fd ff ff e8 ec 23 2b 00 <0f> 0b 48 83 c4 50 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 d6 23 2b 00
RSP: 0018:ffffc9000460f7d8 EFLAGS: 00010093
RAX: ffffffff814dfbb4 RBX: 0000000000010000 RCX: ffff88804e900000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88807ce60b7f R09: 1ffff1100f9cc16f
R10: dffffc0000000000 R11: ffffed100f9cc170 R12: 0000000000000200
R13: ffff8880227341c0 R14: ffff888022734000 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f350470950 CR3: 000000006407f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559
l2cap_chan_send+0x3c5/0x25d0 net/bluetooth/l2cap_core.c:-1
l2cap_sock_sendmsg+0x1aa/0x2b0 net/bluetooth/l2cap_sock.c:1173
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
sock_sendmsg net/socket.c:741 [inline]
kernel_sendmsg+0x234/0x350 net/socket.c:765
bnep_tx_frame net/bluetooth/bnep/core.c:466 [inline]
bnep_session+0x23df/0x29e0 net/bluetooth/bnep/core.c:509
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>


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