[PATCH] drm/tegra: vic: add NULL check on of_match_device() return value

[PATCH] drm/tegra: vic: add NULL check on of_match_device() return value

[Gustavo A. R. Silva]

Check return value from call to of_match_device()
in order to prevent a NULL pointer dereference.

In case of NULL print error message and return.

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
 drivers/gpu/drm/tegra/vic.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
index 47cb1aa..7e11825 100644
--- a/drivers/gpu/drm/tegra/vic.c
+++ b/drivers/gpu/drm/tegra/vic.c
@@ -283,6 +283,11 @@ static int vic_probe(struct platform_device *pdev)
 	int err;
 
 	match = of_match_device(vic_match, dev);
+	if (!match) {
+		dev_err(&pdev->dev, "failed to match device\n");
+		return -ENODEV;
+	}
+
 	vic_config = (struct vic_config *)match->data;
 
 	vic = devm_kzalloc(dev, sizeof(*vic), GFP_KERNEL);
-- 
2.5.0

Re: [PATCH] drm/tegra: vic: add NULL check on of_match_device() return value

[Thierry Reding]

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On Fri, Jul 07, 2017 at 01:16:26AM -0500, Gustavo A. R. Silva wrote:
> Check return value from call to of_match_device()
> in order to prevent a NULL pointer dereference.
> 
> In case of NULL print error message and return.
> 
> Signed-off-by: Gustavo A. R. Silva <garsilva-L1vi/lXTdts+Va1GwOuvDg@public.gmane.org>
> ---
>  drivers/gpu/drm/tegra/vic.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
> index 47cb1aa..7e11825 100644
> --- a/drivers/gpu/drm/tegra/vic.c
> +++ b/drivers/gpu/drm/tegra/vic.c
> @@ -283,6 +283,11 @@ static int vic_probe(struct platform_device *pdev)
>  	int err;
>  
>  	match = of_match_device(vic_match, dev);
> +	if (!match) {
> +		dev_err(&pdev->dev, "failed to match device\n");
> +		return -ENODEV;
> +	}

Someone would have to go to great lengths to trigger this condition,
might as well let it crash as a warning that they've done something
wrong.

Thierry

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Re: [PATCH] drm/tegra: vic: add NULL check on of_match_device() return value

[Gustavo A. R. Silva]

Hi Thierry,

Quoting Thierry Reding <thierry.reding@gmail.com>:

> On Fri, Jul 07, 2017 at 01:16:26AM -0500, Gustavo A. R. Silva wrote:
>> Check return value from call to of_match_device()
>> in order to prevent a NULL pointer dereference.
>>
>> In case of NULL print error message and return.
>>
>> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
>> ---
>>  drivers/gpu/drm/tegra/vic.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
>> index 47cb1aa..7e11825 100644
>> --- a/drivers/gpu/drm/tegra/vic.c
>> +++ b/drivers/gpu/drm/tegra/vic.c
>> @@ -283,6 +283,11 @@ static int vic_probe(struct platform_device *pdev)
>>  	int err;
>>
>>  	match = of_match_device(vic_match, dev);
>> +	if (!match) {
>> +		dev_err(&pdev->dev, "failed to match device\n");
>> +		return -ENODEV;
>> +	}
>
> Someone would have to go to great lengths to trigger this condition,
> might as well let it crash as a warning that they've done something
> wrong.
>

Thanks for clarifying.
--
Gustavo A. R. Silva