media: qcom: camss: Fix potential crash in cleanup in camss_configure_pd()

[PATCH] media: qcom: camss: Fix potential crash in cleanup in camss_configure_pd()

Posted by Dan Carpenter 2 months, 2 weeks ago

This function calls dev_pm_domain_detach(camss->genpd, true) in the
cleanup path.  But calling detach is only necessary if the attach
succeeded.  If it didn't succeed then "camss->genpd" is either an error
pointer or NULL and it leads to a crash.

Fixes: 23aa4f0cd327 ("media: qcom: camss: Move VFE power-domain specifics into vfe.c")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/media/platform/qcom/camss/camss.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
index 1923615f0eea..f4531e7341d4 100644
--- a/drivers/media/platform/qcom/camss/camss.c
+++ b/drivers/media/platform/qcom/camss/camss.c
@@ -2130,10 +2130,8 @@ static int camss_configure_pd(struct camss *camss)
 	if (camss->res->pd_name) {
 		camss->genpd = dev_pm_domain_attach_by_name(camss->dev,
 							    camss->res->pd_name);
-		if (IS_ERR(camss->genpd)) {
-			ret = PTR_ERR(camss->genpd);
-			goto fail_pm;
-		}
+		if (IS_ERR(camss->genpd))
+			return PTR_ERR(camss->genpd);
 	}
 
 	if (!camss->genpd) {
@@ -2141,13 +2141,10 @@ static int camss_configure_pd(struct camss *camss)
 		 */
 		camss->genpd = dev_pm_domain_attach_by_id(camss->dev,
 							  camss->genpd_num - 1);
-	}
-	if (IS_ERR_OR_NULL(camss->genpd)) {
+		if (IS_ERR(camss->genpd))
+			return PTR_ERR(camss->genpd);
 		if (!camss->genpd)
-			ret = -ENODEV;
-		else
-			ret = PTR_ERR(camss->genpd);
-		goto fail_pm;
+			return -ENODEV;
 	}
 	camss->genpd_link = device_link_add(camss->dev, camss->genpd,
 					    DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME |
-- 
2.43.0

Re: [PATCH] media: qcom: camss: Fix potential crash in cleanup in camss_configure_pd()

Posted by Vladimir Zapolskiy 2 months, 2 weeks ago

Hello Dan,

On 9/10/24 22:55, Dan Carpenter wrote:
> This function calls dev_pm_domain_detach(camss->genpd, true) in the
> cleanup path.  But calling detach is only necessary if the attach
> succeeded.  If it didn't succeed then "camss->genpd" is either an error
> pointer or NULL and it leads to a crash.
> 
> Fixes: 23aa4f0cd327 ("media: qcom: camss: Move VFE power-domain specifics into vfe.c")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
>   drivers/media/platform/qcom/camss/camss.c | 15 +++++----------
>   1 file changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
> index 1923615f0eea..f4531e7341d4 100644
> --- a/drivers/media/platform/qcom/camss/camss.c
> +++ b/drivers/media/platform/qcom/camss/camss.c
> @@ -2130,10 +2130,8 @@ static int camss_configure_pd(struct camss *camss)
>   	if (camss->res->pd_name) {
>   		camss->genpd = dev_pm_domain_attach_by_name(camss->dev,
>   							    camss->res->pd_name);
> -		if (IS_ERR(camss->genpd)) {
> -			ret = PTR_ERR(camss->genpd);
> -			goto fail_pm;
> -		}
> +		if (IS_ERR(camss->genpd))
> +			return PTR_ERR(camss->genpd);
>   	}
>   
>   	if (!camss->genpd) {
> @@ -2141,13 +2141,10 @@ static int camss_configure_pd(struct camss *camss)
>   		 */
>   		camss->genpd = dev_pm_domain_attach_by_id(camss->dev,
>   							  camss->genpd_num - 1);
> -	}
> -	if (IS_ERR_OR_NULL(camss->genpd)) {
> +		if (IS_ERR(camss->genpd))
> +			return PTR_ERR(camss->genpd);
>   		if (!camss->genpd)
> -			ret = -ENODEV;
> -		else
> -			ret = PTR_ERR(camss->genpd);
> -		goto fail_pm;
> +			return -ENODEV;
>   	}
>   	camss->genpd_link = device_link_add(camss->dev, camss->genpd,
>   					    DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME |

the problem has been already addressed, it is a real crash, not just
a potential one.

Please see https://lore.kernel.org/all/20240813210342.1765944-1-vladimir.zapolskiy@linaro.org/

--
Best wishes,
Vladimir