Re: [syzbot] WARNING in call_timer_fn

[Thomas Gleixner]

On Thu, Nov 17 2022 at 20:55, Hillf Danton wrote:
> On 17 Nov 2022 12:54:28 +0100 Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> 
>> The work has been canceled already before in the same function and there
>> are some more delayed works which can trigger this.
>> 
>> So no, this whole close_sync() function is prone to teardown races and
>> just slapping a single cancel here without deeper analysis does not cut
>> it.
>
> Agree.
>
> A set of sync cancelations can do the job, given what is defined in struct
> hci_dev wrt workqueue.

It's only part of the solution because you also have to prevent that
work is queued from other parts of the code....