Re: [PATCH net] net: wwan: iosm: fix NULL pointer dereference when removing device

["Kumar, M Chetan" <m.chetan.kumar@linux.intel.com>]

On 5/12/2023 10:35 PM, Simon Horman wrote:
> On Thu, May 11, 2023 at 03:34:44PM +0530, m.chetan.kumar@linux.intel.com wrote:
>> From: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
>>
>> In suspend and resume cycle, the removal and rescan of device ends
>> up in NULL pointer dereference.
>>
>> During driver initialization, if the ipc_imem_wwan_channel_init()
>> fails to get the valid device capabilities it returns an error and
>> further no resource (wwan struct) will be allocated. Now in this
>> situation if driver removal procedure is initiated it would result
>> in NULL pointer exception since unallocated wwan struct is dereferenced
>> inside ipc_wwan_deinit().
>>
>> ipc_imem_run_state_worker() to handle the called functions return value
>> and to release the resource in failure case. It also reports the link
>> down event in failure cases. The user space application can handle this
>> event to do a device reset for restoring the device communication.
>>
>> Fixes: 3670970dd8c6 ("net: iosm: shared memory IPC interface")
>> Reported-by: Samuel Wein PhD <sam@samwein.com>
>> Closes: https://lore.kernel.org/netdev/20230427140819.1310f4bd@kernel.org/T/
>> Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
> 

<skip>

> err_out:
> 	ipc_mux_deinit(ipc_imem->mux);
> 	ipc_uevent_send(ipc_imem->dev, UEVENT_CD_READY_LINK_DOWN);
> 
>>   }

Thank you for reviewing the patch and sharing the feedback.
I will post the v2 with the above suggested changes.