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* [PATCH] drm/msm: Fix NULL deref in adreno_load_gpu
@ 2017-12-14  5:41 Archit Taneja
  2017-12-15 15:33 ` Jordan Crouse
  2017-12-22 10:11 ` [PATCH v2] " Archit Taneja
  0 siblings, 2 replies; 5+ messages in thread
From: Archit Taneja @ 2017-12-14  5:41 UTC (permalink / raw)
  To: robdclark; +Cc: dri-devel, linux-arm-msm, Archit Taneja

The msm/kms driver should work even if there is no GPU device specified
in DT. Currently, we get a NULL dereference crash in adreno_load_gpu
since the driver assumes that priv->gpu_pdev is non-NULL.

Perform an additional check on priv->gpu_pdev before trying to retrieve
the msm_gpu pointer from it.

Fixes: eec874ce5ff1 (drm/msm/adreno: load gpu at probe/bind time)

Signed-off-by: Archit Taneja <architt@codeaurora.org>
---
 drivers/gpu/drm/msm/adreno/adreno_device.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
index 05022ea2a007..ac60cf3c794e 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_device.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
@@ -124,10 +124,17 @@ const struct adreno_info *adreno_info(struct adreno_rev rev)
 struct msm_gpu *adreno_load_gpu(struct drm_device *dev)
 {
 	struct msm_drm_private *priv = dev->dev_private;
-	struct platform_device *pdev = priv->gpu_pdev;
-	struct msm_gpu *gpu = platform_get_drvdata(priv->gpu_pdev);
+	struct platform_device *pdev;
+	struct msm_gpu *gpu;
 	int ret;
 
+	pdev = priv->gpu_pdev;
+	if (!pdev) {
+		dev_dbg(dev->dev, "no adreno platform device found\n");
+		return NULL;
+	}
+
+	gpu = platform_get_drvdata(pdev);
 	if (!gpu) {
 		dev_err(dev->dev, "no adreno device\n");
 		return NULL;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH] drm/msm: Fix NULL deref in adreno_load_gpu
  2017-12-14  5:41 [PATCH] drm/msm: Fix NULL deref in adreno_load_gpu Archit Taneja
@ 2017-12-15 15:33 ` Jordan Crouse
  2017-12-20  6:48   ` Archit Taneja
  2017-12-22 10:11 ` [PATCH v2] " Archit Taneja
  1 sibling, 1 reply; 5+ messages in thread
From: Jordan Crouse @ 2017-12-15 15:33 UTC (permalink / raw)
  To: Archit Taneja; +Cc: robdclark, linux-arm-msm, dri-devel

On Thu, Dec 14, 2017 at 11:11:50AM +0530, Archit Taneja wrote:
> The msm/kms driver should work even if there is no GPU device specified
> in DT. Currently, we get a NULL dereference crash in adreno_load_gpu
> since the driver assumes that priv->gpu_pdev is non-NULL.
> 
> Perform an additional check on priv->gpu_pdev before trying to retrieve
> the msm_gpu pointer from it.
> 
> Fixes: eec874ce5ff1 (drm/msm/adreno: load gpu at probe/bind time)
> 
> Signed-off-by: Archit Taneja <architt@codeaurora.org>
> ---
>  drivers/gpu/drm/msm/adreno/adreno_device.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
> index 05022ea2a007..ac60cf3c794e 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_device.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
> @@ -124,10 +124,17 @@ const struct adreno_info *adreno_info(struct adreno_rev rev)
>  struct msm_gpu *adreno_load_gpu(struct drm_device *dev)
>  {
>  	struct msm_drm_private *priv = dev->dev_private;
> -	struct platform_device *pdev = priv->gpu_pdev;
> -	struct msm_gpu *gpu = platform_get_drvdata(priv->gpu_pdev);
> +	struct platform_device *pdev;
> +	struct msm_gpu *gpu;
>  	int ret;
>  
> +	pdev = priv->gpu_pdev;
> +	if (!pdev) {
> +		dev_dbg(dev->dev, "no adreno platform device found\n");
> +		return NULL;
> +	}
> +
> +	gpu = platform_get_drvdata(pdev);
>  	if (!gpu) {
>  		dev_err(dev->dev, "no adreno device\n");
>  		return NULL;

Obviously correct fix but I can't help but think that we should share the same
error message, so something like:

struct msm_gpu *gpu = NULL;

.. 

if (priv->gpu_pdev)
   gpu = platform_get_drvdata(priv->gpu_pdev);

if (!gpu) {
	dev_err(dev->dev, "No GPU device was was found\n");
 	return NULL;
}

(also, I can't help but think maybe that dev_err should be a ONCE so you don't
get a nasty message every time you open the file descriptor).

Jordan

-- 
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] drm/msm: Fix NULL deref in adreno_load_gpu
  2017-12-15 15:33 ` Jordan Crouse
@ 2017-12-20  6:48   ` Archit Taneja
  0 siblings, 0 replies; 5+ messages in thread
From: Archit Taneja @ 2017-12-20  6:48 UTC (permalink / raw)
  To: robdclark, linux-arm-msm, dri-devel



On 12/15/2017 09:03 PM, Jordan Crouse wrote:
> On Thu, Dec 14, 2017 at 11:11:50AM +0530, Archit Taneja wrote:
>> The msm/kms driver should work even if there is no GPU device specified
>> in DT. Currently, we get a NULL dereference crash in adreno_load_gpu
>> since the driver assumes that priv->gpu_pdev is non-NULL.
>>
>> Perform an additional check on priv->gpu_pdev before trying to retrieve
>> the msm_gpu pointer from it.
>>
>> Fixes: eec874ce5ff1 (drm/msm/adreno: load gpu at probe/bind time)
>>
>> Signed-off-by: Archit Taneja <architt@codeaurora.org>
>> ---
>>   drivers/gpu/drm/msm/adreno/adreno_device.c | 11 +++++++++--
>>   1 file changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
>> index 05022ea2a007..ac60cf3c794e 100644
>> --- a/drivers/gpu/drm/msm/adreno/adreno_device.c
>> +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
>> @@ -124,10 +124,17 @@ const struct adreno_info *adreno_info(struct adreno_rev rev)
>>   struct msm_gpu *adreno_load_gpu(struct drm_device *dev)
>>   {
>>   	struct msm_drm_private *priv = dev->dev_private;
>> -	struct platform_device *pdev = priv->gpu_pdev;
>> -	struct msm_gpu *gpu = platform_get_drvdata(priv->gpu_pdev);
>> +	struct platform_device *pdev;
>> +	struct msm_gpu *gpu;
>>   	int ret;
>>   
>> +	pdev = priv->gpu_pdev;
>> +	if (!pdev) {
>> +		dev_dbg(dev->dev, "no adreno platform device found\n");
>> +		return NULL;
>> +	}
>> +
>> +	gpu = platform_get_drvdata(pdev);
>>   	if (!gpu) {
>>   		dev_err(dev->dev, "no adreno device\n");
>>   		return NULL;
> 
> Obviously correct fix but I can't help but think that we should share the same
> error message, so something like:
> 
> struct msm_gpu *gpu = NULL;
> 
> ..
> 
> if (priv->gpu_pdev)
>     gpu = platform_get_drvdata(priv->gpu_pdev);
> 
> if (!gpu) {
> 	dev_err(dev->dev, "No GPU device was was found\n");
>   	return NULL;
> }
> 
> (also, I can't help but think maybe that dev_err should be a ONCE so you don't
> get a nasty message every time you open the file descriptor).

This approach looks better. I'll re-spin.

Thanks,
Archit

> 
> Jordan
> 

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH v2] drm/msm: Fix NULL deref in adreno_load_gpu
  2017-12-14  5:41 [PATCH] drm/msm: Fix NULL deref in adreno_load_gpu Archit Taneja
  2017-12-15 15:33 ` Jordan Crouse
@ 2017-12-22 10:11 ` Archit Taneja
  2018-01-02 18:32   ` Jordan Crouse
  1 sibling, 1 reply; 5+ messages in thread
From: Archit Taneja @ 2017-12-22 10:11 UTC (permalink / raw)
  To: robdclark, jcrouse; +Cc: linux-arm-msm, dri-devel

The msm/kms driver should work even if there is no GPU device specified
in DT. Currently, we get a NULL dereference crash in adreno_load_gpu
since the driver assumes that priv->gpu_pdev is non-NULL.

Perform an additional check on priv->gpu_pdev before trying to retrieve
the msm_gpu pointer from it.

v2: Incorporate Jordan's comments:
- Simplify the check to share the same error message.
- Use dev_err_once() to avoid an error message every time we open the
  drm device fd.

Fixes: eec874ce5ff1 (drm/msm/adreno: load gpu at probe/bind time)

Signed-off-by: Archit Taneja <architt@codeaurora.org>
---
 drivers/gpu/drm/msm/adreno/adreno_device.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
index 05022ea2a007..bfb3d689f47d 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_device.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
@@ -125,11 +125,14 @@ struct msm_gpu *adreno_load_gpu(struct drm_device *dev)
 {
 	struct msm_drm_private *priv = dev->dev_private;
 	struct platform_device *pdev = priv->gpu_pdev;
-	struct msm_gpu *gpu = platform_get_drvdata(priv->gpu_pdev);
+	struct msm_gpu *gpu = NULL;
 	int ret;
 
+	if (pdev)
+		gpu = platform_get_drvdata(pdev);
+
 	if (!gpu) {
-		dev_err(dev->dev, "no adreno device\n");
+		dev_err_once(dev->dev, "no GPU device was found\n");
 		return NULL;
 	}
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH v2] drm/msm: Fix NULL deref in adreno_load_gpu
  2017-12-22 10:11 ` [PATCH v2] " Archit Taneja
@ 2018-01-02 18:32   ` Jordan Crouse
  0 siblings, 0 replies; 5+ messages in thread
From: Jordan Crouse @ 2018-01-02 18:32 UTC (permalink / raw)
  To: Archit Taneja; +Cc: linux-arm-msm, dri-devel

On Fri, Dec 22, 2017 at 03:41:13PM +0530, Archit Taneja wrote:
> The msm/kms driver should work even if there is no GPU device specified
> in DT. Currently, we get a NULL dereference crash in adreno_load_gpu
> since the driver assumes that priv->gpu_pdev is non-NULL.
> 
> Perform an additional check on priv->gpu_pdev before trying to retrieve
> the msm_gpu pointer from it.
> 
> v2: Incorporate Jordan's comments:
> - Simplify the check to share the same error message.
> - Use dev_err_once() to avoid an error message every time we open the
>   drm device fd.
> 
> Fixes: eec874ce5ff1 (drm/msm/adreno: load gpu at probe/bind time)
> 
> Signed-off-by: Archit Taneja <architt@codeaurora.org>

Acked-by: Jordan Crouse <jcrouse@codeaurora.org>

> ---
>  drivers/gpu/drm/msm/adreno/adreno_device.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
> index 05022ea2a007..bfb3d689f47d 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_device.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
> @@ -125,11 +125,14 @@ struct msm_gpu *adreno_load_gpu(struct drm_device *dev)
>  {
>  	struct msm_drm_private *priv = dev->dev_private;
>  	struct platform_device *pdev = priv->gpu_pdev;
> -	struct msm_gpu *gpu = platform_get_drvdata(priv->gpu_pdev);
> +	struct msm_gpu *gpu = NULL;
>  	int ret;
>  
> +	if (pdev)
> +		gpu = platform_get_drvdata(pdev);
> +
>  	if (!gpu) {
> -		dev_err(dev->dev, "no adreno device\n");
> +		dev_err_once(dev->dev, "no GPU device was found\n");
>  		return NULL;
>  	}

-- 
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2018-01-02 18:32 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-12-14  5:41 [PATCH] drm/msm: Fix NULL deref in adreno_load_gpu Archit Taneja
2017-12-15 15:33 ` Jordan Crouse
2017-12-20  6:48   ` Archit Taneja
2017-12-22 10:11 ` [PATCH v2] " Archit Taneja
2018-01-02 18:32   ` Jordan Crouse

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