[syzbot] [bluetooth?] WARNING in hci_conn_drop (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2213e57a69f0 Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=12e2ff12580000
kernel config: https://syzkaller.appspot.com/x/.config?x=714d45b6135c308e
dashboard link: https://syzkaller.appspot.com/bug?extid=bf427d0e03a779974eee
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/bf4625d47a8f/disk-2213e57a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/270abffcbf3c/vmlinux-2213e57a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1f0f6eb3e385/Image-2213e57a.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bf427d...@syzkaller.appspotmail.com

------------[ cut here ]------------
workqueue: cannot queue hci_conn_timeout on wq hci4
WARNING: CPU: 1 PID: 6638 at kernel/workqueue.c:2256 __queue_work+0xe10/0x1210 kernel/workqueue.c:2254
Modules linked in:
CPU: 1 UID: 0 PID: 6638 Comm: kworker/1:6 Not tainted syzkaller #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Workqueue: events l2cap_chan_timeout
pstate: 634000c5 (nZCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : __queue_work+0xe10/0x1210 kernel/workqueue.c:2254
lr : __queue_work+0xe10/0x1210 kernel/workqueue.c:2254
sp : ffff80009d4e77e0
x29: ffff80009d4e7830 x28: 1fffe0001b418c00 x27: ffff0000d493dac0
x26: 0000000000000008 x25: dfff800000000000 x24: ffff0000c9ffa800
x23: ffff0000c9ffa9c0 x22: 0000000004208060 x21: 1fffe000193ff538
x20: ffff800092e27000 x19: ffff0000d9fe0960 x18: 00000000ffffffff
x17: ffff80009353a000 x16: ffff80008b021030 x15: 0000000000000001
x14: 1fffe000337938f2 x13: 0000000000000000 x12: 0000000000000000
x11: ffff6000337938f3 x10: 0000000000ff0100 x9 : 1a6f38d4427b3b00
x8 : 1a6f38d4427b3b00 x7 : ffff800080565b6c x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000000 x3 : ffff8000807e0688
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
__queue_work+0xe10/0x1210 kernel/workqueue.c:2254 (P)
__queue_delayed_work+0xfc/0x2c8 kernel/workqueue.c:2507
queue_delayed_work_on+0xe4/0x194 kernel/workqueue.c:2559
queue_delayed_work include/linux/workqueue.h:684 [inline]
hci_conn_drop+0x174/0x280 include/net/bluetooth/hci_core.h:1675
l2cap_chan_del+0x228/0x470 net/bluetooth/l2cap_core.c:671
l2cap_chan_close+0x424/0x684 net/bluetooth/l2cap_core.c:-1
l2cap_chan_timeout+0x120/0x280 net/bluetooth/l2cap_core.c:431
process_one_work+0x7e8/0x155c kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x958/0xed8 kernel/workqueue.c:3400
kthread+0x5fc/0x75c kernel/kthread.c:463
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844
irq event stamp: 105130
hardirqs last enabled at (105129): [<ffff800080429388>] __cancel_work+0x158/0x218 kernel/workqueue.c:4344
hardirqs last disabled at (105130): [<ffff8000804249b8>] queue_delayed_work_on+0x54/0x194 kernel/workqueue.c:2555
softirqs last enabled at (105122): [<ffff8000803da960>] softirq_handle_end kernel/softirq.c:425 [inline]
softirqs last enabled at (105122): [<ffff8000803da960>] handle_softirqs+0xaf8/0xc88 kernel/softirq.c:607
softirqs last disabled at (104025): [<ffff800080022028>] __do_softirq+0x14/0x20 kernel/softirq.c:613
---[ end trace 0000000000000000 ]---


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