# Re: WARNING in \_\_queue\_work

- From: Lai Jiangshan \<jiangshanlai@gmail.com\>
- Date: 2021-09-20 16:09:58 
- List: linux-bluetooth
- Page: https://ratatoskr.run/linux-bluetooth/2021/09/1514847

```text
On Mon, Sep 20, 2021 at 9:13 PM Hao Sun [ref] wrote:
>
> Hello,
>
> When using Healer to fuzz the latest Linux kernel, the following crash
> was triggered.
>
> HEAD commit: 4357f03d6611 Merge tag 'pm-5.15-rc2
> git tree: upstream
> console output:
> https://drive.google.com/file/d/10dFvcbiBLWmCS05daXKnBH-ZEa8M7aI9/view?usp=sharing
> kernel config: https://drive.google.com/file/d/1HKZtF_s3l6PL3OoQbNq_ei9CdBus-Tz0/view?usp=sharing
>
> Sorry, I don't have a reproducer for this crash, hope the symbolized
> report can help.
> If you fix this issue, please add the following tag to the commit:
> Reported-by: Hao Sun <redacted>
>
> Bluetooth: hci1: command 0x040f tx timeout
> ------------[ cut here ]------------
> WARNING: CPU: 2 PID: 10555 at kernel/workqueue.c:1440
> __queue_work+0x437/0x8d0 kernel/workqueue.c:1440
> Modules linked in:
> CPU: 2 PID: 10555 Comm: kworker/2:7 Not tainted 5.15.0-rc1+ #19
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
> Workqueue: events hci_cmd_timeout

Add CC to Bluetooth people to deal with it together since the code
is also just changed.

It seems cmd_timer or cmd_timer.work is still active or pending for
unknown reasons when hdev->workqueue is being drained.
```