Re: [PATCH v2] kern: perform NULL check in unregister paths (command/extcmd)

[Avnish Chouhan <avnish@linux.ibm.com>]

On 2025-09-10 18:27, grub-devel-request@gnu.org wrote:
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Tue, 9 Sep 2025 11:09:55 -0400
> From: Stefan Berger <stefanb@linux.ibm.com>
> To: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>, Srish Srinivasan
> 	<ssrish@linux.ibm.com>
> Cc: grub-devel@gnu.org, daniel.kiper@oracle.com, phcoder@gmail.com,
> 	nayna@linux.ibm.com, sridharm@linux.ibm.com
> Subject: Re: [PATCH v2] kern: perform NULL check in unregister paths
> 	(command/extcmd)
> Message-ID: <57eced6f-6b12-4d95-953c-98329bce3b82@linux.ibm.com>
> Content-Type: text/plain; charset=UTF-8; format=flowed
> 
> 
> 
> On 9/9/25 4:22 AM, Sudhakar Kuppusamy wrote:
>> 
>> 
>>> On 9 Sep 2025, at 12:25 PM, Srish Srinivasan <ssrish@linux.ibm.com> 
>>> wrote:
>>> 
>>> Many modules call grub_unregister_{command(), extcmd()} from
>>> GRUB_MOD_FINI() without checking for a failure in registration.
>>> This could lead to a NULL pointer dereference in unregistration.
>>> 
>>> Perform explicit NULL check in both the unregister helpers.
>>> 
>>> Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
>> 
>> Reviewed-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
> 

Hi Srish,
Thank you so much for the patch!

A failure in registration will anyways returns NULL. Re checking it 
might not make a sense. Do you have any specific scenario for this?
Thank you!


Regards,
Avnish Chouhan

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