Re: [PATCH iwl-net 2/2] idpf: fix idpf_vc_core_init error path

["Linga, Pavan Kumar" <pavan.kumar.linga@intel.com>]

On 10/24/2024 7:39 AM, Simon Horman wrote:
> On Tue, Oct 22, 2024 at 10:35:27AM -0700, Pavan Kumar Linga wrote:
>> In an event where the platform running the device control plane
>> is rebooted, reset is detected on the driver. It releases
>> all the resources and waits for the reset to complete. Once the
>> reset is done, it tries to build the resources back. At this
>> time if the device control plane is not yet started, then
>> the driver timeouts on the virtchnl message and retries to
>> establish the mailbox again.
>>
>> In the retry flow, mailbox is deinitialized but the mailbox
>> workqueue is still alive and polling for the mailbox message.
>> This results in accessing the released control queue leading to
>> null-ptr-deref. Fix it by unrolling the work queue cancellation
>> and mailbox deinitialization in the order which they got
>> initialized.
>>
>> Also remove the redundant scheduling of the mailbox task in
>> idpf_vc_core_init.
> 
> I think it might be better to move this last change into a separate patch
> targeted at iwl rather than iwl-net. It isn't a fix, right?
> 

If we do not make that change in this patch, it results in calling 
cancel_delayed_work_sync twice in case of an error in idpf_vc_core_init 
(err_intr_req). Looks like there aren't any side effects of calling 
cancel_delayed_work_sync twice. I will remove the said changes from this 
patch.

Thanks,
Pavan

>>
>> Fixes: 4930fbf419a7 ("idpf: add core init and interrupt request")
>> Fixes: 34c21fa894a1 ("idpf: implement virtchnl transaction manager")
>> Cc: stable@vger.kernel.org # 6.9+
>> Reviewed-by: Tarun K Singh <tarun.k.singh@intel.com>
>> Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
> 
> ...