Re: [PATCH] drm/msm/hdmi: check return value after calling platform_get_resource_byname()

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

On 4/21/2022 8:22 PM, Yang Yingliang wrote:
> It will cause null-ptr-deref if platform_get_resource_byname() returns NULL,
> we need check the return value.
>
> Fixes: c6a57a50ad56 ("drm/msm/hdmi: add hdmi hdcp support (V3)")
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> ---
>   drivers/gpu/drm/msm/hdmi/hdmi.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.c b/drivers/gpu/drm/msm/hdmi/hdmi.c
> index ec324352e862..07e2ad527af9 100644
> --- a/drivers/gpu/drm/msm/hdmi/hdmi.c
> +++ b/drivers/gpu/drm/msm/hdmi/hdmi.c
> @@ -142,6 +142,10 @@ static struct hdmi *msm_hdmi_init(struct platform_device *pdev)
>   	/* HDCP needs physical address of hdmi register */
>   	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>   		config->mmio_name);
> +	if (!res) {
> +		ret = -EINVAL;
> +		goto fail;
> +	}
>   	hdmi->mmio_phy_addr = res->start;
>   
>   	hdmi->qfprom_mmio = msm_ioremap(pdev, config->qfprom_mmio_name);