[RESEND PATCH v2] firmware: qcom: scm: fix a NULL-pointer dereference

[RESEND PATCH v2] firmware: qcom: scm: fix a NULL-pointer dereference

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

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@gmail.com>
Closes: https://lore.kernel.org/lkml/692cfe9a-8c05-4ce4-813e-82b3f310019a@gmail.com/
Reviewed-by: Konrad Dybcio <konradybcio@kernel.org>
Tested-by: Rudraksha Gupta <guptarud@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
I dropped patch 2/2 and am resending this separately rebased on top of
v6.12-rc1.

 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

Re: [RESEND PATCH v2] firmware: qcom: scm: fix a NULL-pointer dereference

[Kuldeep Singh]

On 9/30/2024 2:03 PM, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> 
> 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@gmail.com>
> Closes: https://lore.kernel.org/lkml/692cfe9a-8c05-4ce4-813e-82b3f310019a@gmail.com/
> Reviewed-by: Konrad Dybcio <konradybcio@kernel.org>
> Tested-by: Rudraksha Gupta <guptarud@gmail.com>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Reviewed-by: Stephan Gerhold <stephan.gerhold@linaro.org>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Reviewed-by: Kuldeep Singh <quic_kuldsing@quicinc.com>

> ---
> I dropped patch 2/2 and am resending this separately rebased on top of
> v6.12-rc1.
> 
>  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)

-- 
Regards
Kuldeep

Re: [RESEND PATCH v2] firmware: qcom: scm: fix a NULL-pointer dereference

[Bjorn Andersson]

On Mon, 30 Sep 2024 10:33:28 +0200, Bartosz Golaszewski wrote:
> 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.
> 
> 

Applied, thanks!

[1/1] firmware: qcom: scm: fix a NULL-pointer dereference
      commit: ca61d6836e6f4442a77762e1074d2706a2a6e578

Best regards,
-- 
Bjorn Andersson <andersson@kernel.org>