[PATCH -next] drm/meson: Fix potential NULL dereference in meson_drv_bind_master()

[PATCH -next] drm/meson: Fix potential NULL dereference in meson_drv_bind_master()

[Wei Yongjun]

platform_get_resource_byname() may fail and return NULL, so we should
better check it's return value to avoid a NULL pointer dereference
a bit later in the code.

This is detected by Coccinelle semantic patch.

@@
expression pdev, res, n, t, e, e1, e2;
@@

res = platform_get_resource_byname(pdev, t, n);
+ if (!res)
+   return -EINVAL;
... when != res == NULL
e = devm_ioremap(e1, res->start, e2);

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
---
 drivers/gpu/drm/meson/meson_drv.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
index 3baceb7..32b1a6c 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -197,6 +197,8 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
 	priv->io_base = regs;
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hhi");
+	if (!res)
+		return -EINVAL;
 	/* Simply ioremap since it may be a shared register zone */
 	regs = devm_ioremap(dev, res->start, resource_size(res));
 	if (!regs) {
@@ -213,6 +215,8 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
 	}
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dmc");
+	if (!res)
+		return -EINVAL;
 	/* Simply ioremap since it may be a shared register zone */
 	regs = devm_ioremap(dev, res->start, resource_size(res));
 	if (!regs) {

[PATCH -next] drm/meson: Fix potential NULL dereference in meson_drv_bind_master()

[Neil Armstrong]

On 20/03/2018 15:20, Wei Yongjun wrote:
> platform_get_resource_byname() may fail and return NULL, so we should
> better check it's return value to avoid a NULL pointer dereference
> a bit later in the code.
> 
> This is detected by Coccinelle semantic patch.
> 
> @@
> expression pdev, res, n, t, e, e1, e2;
> @@
> 
> res = platform_get_resource_byname(pdev, t, n);
> + if (!res)
> +   return -EINVAL;
> ... when != res == NULL
> e = devm_ioremap(e1, res->start, e2);
> 
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> ---
>  drivers/gpu/drm/meson/meson_drv.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
> index 3baceb7..32b1a6c 100644
> --- a/drivers/gpu/drm/meson/meson_drv.c
> +++ b/drivers/gpu/drm/meson/meson_drv.c
> @@ -197,6 +197,8 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>  	priv->io_base = regs;
>  
>  	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hhi");
> +	if (!res)
> +		return -EINVAL;
>  	/* Simply ioremap since it may be a shared register zone */
>  	regs = devm_ioremap(dev, res->start, resource_size(res));
>  	if (!regs) {
> @@ -213,6 +215,8 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>  	}
>  
>  	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dmc");
> +	if (!res)
> +		return -EINVAL;
>  	/* Simply ioremap since it may be a shared register zone */
>  	regs = devm_ioremap(dev, res->start, resource_size(res));
>  	if (!regs) {
> 
> 
> _______________________________________________
> linux-amlogic mailing list
> linux-amlogic at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-amlogic
> 
Thanks,

Acked-by: Neil Armstrong <narmstrong@baylibre.com>

[PATCH -next] drm/meson: Fix potential NULL dereference in meson_drv_bind_master()

[Neil Armstrong]

On 20/03/2018 16:04, Neil Armstrong wrote:
> On 20/03/2018 15:20, Wei Yongjun wrote:
>> platform_get_resource_byname() may fail and return NULL, so we should
>> better check it's return value to avoid a NULL pointer dereference
>> a bit later in the code.
>>
>> This is detected by Coccinelle semantic patch.
>>
>> @@
>> expression pdev, res, n, t, e, e1, e2;
>> @@
>>
>> res = platform_get_resource_byname(pdev, t, n);
>> + if (!res)
>> +   return -EINVAL;
>> ... when != res == NULL
>> e = devm_ioremap(e1, res->start, e2);
>>
>> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
>> ---
>>  drivers/gpu/drm/meson/meson_drv.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
>> index 3baceb7..32b1a6c 100644
>> --- a/drivers/gpu/drm/meson/meson_drv.c
>> +++ b/drivers/gpu/drm/meson/meson_drv.c
>> @@ -197,6 +197,8 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>>  	priv->io_base = regs;
>>  
>>  	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hhi");
>> +	if (!res)
>> +		return -EINVAL;
>>  	/* Simply ioremap since it may be a shared register zone */
>>  	regs = devm_ioremap(dev, res->start, resource_size(res));
>>  	if (!regs) {
>> @@ -213,6 +215,8 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>>  	}
>>  
>>  	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dmc");
>> +	if (!res)
>> +		return -EINVAL;
>>  	/* Simply ioremap since it may be a shared register zone */
>>  	regs = devm_ioremap(dev, res->start, resource_size(res));
>>  	if (!regs) {
>>
>>
>> _______________________________________________
>> linux-amlogic mailing list
>> linux-amlogic at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-amlogic
>>
> Thanks,
> 
> Acked-by: Neil Armstrong <narmstrong@baylibre.com>
> 

Applied to drm-misc-next