Re: [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@xxxxxxxxxx>
>> ---
>>  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) {
>>
>>
>> _______________________________________________
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>>
> Thanks,
> 
> Acked-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> 

Applied to drm-misc-next