Re: [PATCH] [media] VPU: mediatek: fix null pointer dereference on pdev

From: andrew-ct chen
Date: Thu Sep 08 2016 - 21:25:23 EST


On Wed, 2016-09-07 at 18:10 +0100, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> pdev is being null checked, however, prior to that it is being
> dereferenced by platform_get_drvdata. Move the assignments of
> vpu and run to after the pdev null check to avoid a potential
> null pointer dereference.
>

Reviewed-by:Andrew-CT Chen <andrew-ct.chen@xxxxxxxxxxxx>

> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
> drivers/media/platform/mtk-vpu/mtk_vpu.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/platform/mtk-vpu/mtk_vpu.c b/drivers/media/platform/mtk-vpu/mtk_vpu.c
> index c9bf58c..43907a3 100644
> --- a/drivers/media/platform/mtk-vpu/mtk_vpu.c
> +++ b/drivers/media/platform/mtk-vpu/mtk_vpu.c
> @@ -523,9 +523,9 @@ static int load_requested_vpu(struct mtk_vpu *vpu,
>
> int vpu_load_firmware(struct platform_device *pdev)
> {
> - struct mtk_vpu *vpu = platform_get_drvdata(pdev);
> + struct mtk_vpu *vpu;
> struct device *dev = &pdev->dev;
> - struct vpu_run *run = &vpu->run;
> + struct vpu_run *run;
> const struct firmware *vpu_fw = NULL;
> int ret;
>
> @@ -534,6 +534,9 @@ int vpu_load_firmware(struct platform_device *pdev)
> return -EINVAL;
> }
>
> + vpu = platform_get_drvdata(pdev);
> + run = &vpu->run;
> +
> mutex_lock(&vpu->vpu_mutex);
> if (vpu->fw_loaded) {
> mutex_unlock(&vpu->vpu_mutex);