[v6.1] WARNING in l2cap_chan_del (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cd9b81672742 Linux 6.1.161
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17384bfa580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0605c5af04d7603
dashboard link: https://syzkaller.appspot.com/bug?extid=a69018e3614e2733600a
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/7c7d6fd2ef9f/disk-cd9b8167.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/544b7fd5d4e0/vmlinux-cd9b8167.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3454f19d3753/bzImage-cd9b8167.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a69018...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 18764 at kernel/workqueue.c:1441 __queue_work+0xe2d/0xfb0 kernel/workqueue.c:1441
Modules linked in:
CPU: 1 PID: 18764 Comm: syz.6.3490 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__queue_work+0xe2d/0xfb0 kernel/workqueue.c:1441
Code: e9 9d fc ff ff 48 8b 0c 24 80 e1 07 80 c1 03 38 c1 0f 8c c7 fc ff ff 48 8b 3c 24 e8 0d 00 7f 00 e9 b9 fc ff ff e8 23 15 2e 00 <0f> 0b 48 83 c4 60 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 0d 15 2e 00
RSP: 0018:ffffc9000f047588 EFLAGS: 00010087
RAX: ffffffff81545d4d RBX: 0000000000010000 RCX: 0000000000080000
RDX: ffffc9000f564000 RSI: 00000000000007c8 RDI: 00000000000007c9
RBP: 0000000000000000 R08: ffff88802f1c0337 R09: 1ffff11005e38066
R10: dffffc0000000000 R11: ffffed1005e38067 R12: ffff888056bd6800
R13: ffff888056bd69c0 R14: 0000000000000008 R15: ffff88802f1c0330
FS: 00007f11d26a76c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c40f90c CR3: 0000000067bfa000 CR4: 00000000003506e0
Call Trace:
<TASK>
queue_delayed_work_on+0x12d/0x1f0 kernel/workqueue.c:1704
l2cap_chan_del+0x2d8/0x620 net/bluetooth/l2cap_core.c:697
l2cap_chan_close+0xf9/0x800 net/bluetooth/l2cap_core.c:885
l2cap_sock_shutdown+0x90b/0xf60 net/bluetooth/l2cap_sock.c:1404
l2cap_sock_release+0x8a/0x1e0 net/bluetooth/l2cap_sock.c:1451
__sock_release net/socket.c:654 [inline]
sock_close+0xd5/0x240 net/socket.c:1399
__fput+0x22c/0x920 fs/file_table.c:320
task_work_run+0x1d0/0x260 kernel/task_work.c:203
get_signal+0x11a6/0x1350 kernel/signal.c:2648
arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f11d179acb9
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:00007f11d26a7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffffc RBX: 00007f11d1a15fa0 RCX: 00007f11d179acb9
RDX: 000000000000000e RSI: 0000200000000040 RDI: 0000000000000004
RBP: 00007f11d1808bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f11d1a16038 R14: 00007f11d1a15fa0 R15: 00007ffea1f13f28
</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