2017-07-07 06:16:31

by Gustavo A. R. Silva

[permalink] [raw]

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

---

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 <[email protected]>
---
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

2017-07-07 09:25:57

by Thierry Reding

[permalink] [raw]

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

---

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 <[email protected]>
> ---
> 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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2017-07-10 19:29:38

by Gustavo A. R. Silva

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

---

Hi Thierry,

Quoting Thierry Reding <[email protected]>:

> 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 <[email protected]>
>> ---
>> 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