Re: [PATCH v2 1/2] firmware: qcom: scm: fix a NULL-pointer dereference

[Stephan Gerhold]

On Wed, Sep 11, 2024 at 11:07:03AM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> 
> Some SCM calls can be invoked with __scm being NULL (the driver may not
> have been and will not be probed as there's no SCM entry in device-tree).
> Make sure we don't dereference a NULL pointer.
> 
> Fixes: 449d0d84bcd8 ("firmware: qcom: scm: smc: switch to using the SCM allocator")
> Reported-by: Rudraksha Gupta <guptarud@xxxxxxxxx>
> Closes: https://lore.kernel.org/lkml/692cfe9a-8c05-4ce4-813e-82b3f310019a@xxxxxxxxx/
> Reviewed-by: Konrad Dybcio <konradybcio@xxxxxxxxxx>
> Tested-by: Rudraksha Gupta <guptarud@xxxxxxxxx>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Reviewed-by: Stephan Gerhold <stephan.gerhold@xxxxxxxxxx>

> ---
>  drivers/firmware/qcom/qcom_scm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
> index 10986cb11ec0..8bac4915c211 100644
> --- a/drivers/firmware/qcom/qcom_scm.c
> +++ b/drivers/firmware/qcom/qcom_scm.c
> @@ -216,7 +216,7 @@ static DEFINE_SPINLOCK(scm_query_lock);
>  
>  struct qcom_tzmem_pool *qcom_scm_get_tzmem_pool(void)
>  {
> -	return __scm->mempool;
> +	return __scm ? __scm->mempool : NULL;
>  }
>  
>  static enum qcom_scm_convention __get_convention(void)
> 
> -- 
> 2.43.0
>