Re: [Patch 02/16] media: ti-vpe: vpe: Add missing null pointer checks

Austin Kim
2019-09-29T00:08:51Z

2019년 9월 28일 (토) 오전 3:37, Benoit Parrot <bparrot@ti.com>님이 작성:
>
> A few NULL pointer checks were missing.
> Add check with appropriate return code.
>
> Signed-off-by: Benoit Parrot <bparrot@ti.com>
> ---
> drivers/media/platform/ti-vpe/vpe.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/ti-vpe/vpe.c b/drivers/media/platform/ti-vpe/vpe.c
> index 5ba72445584d..56f60dbea15c 100644
> --- a/drivers/media/platform/ti-vpe/vpe.c
> +++ b/drivers/media/platform/ti-vpe/vpe.c
> @@ -1537,6 +1537,8 @@ static int vpe_g_fmt(struct file *file, void *priv, struct v4l2_format *f)
> return -EINVAL;
>
> q_data = get_q_data(ctx, f->type);
> + if (!q_data)
> + return -EINVAL;

With this commit, it seems that 'Null Pointer Dereference' could be
avoidable even though 'get_q_data(ctx, f->type);' returns NULL.

* Original Code:
q_data = get_q_data(ctx, f->type);
// q_data = NULL;

pix->width = q_data->width;
// pix->width = (NULL)->width;
// In this case, data abort would be raised.

>
> pix->width = q_data->width;
> pix->height = q_data->height;
> @@ -2001,6 +2003,8 @@ static int vpe_queue_setup(struct vb2_queue *vq,
> struct vpe_q_data *q_data;
>
> q_data = get_q_data(ctx, vq->type);
> + if (!q_data)
> + return -EINVAL;
>
> *nplanes = q_data->nplanes;
>
> @@ -2025,6 +2029,8 @@ static int vpe_buf_prepare(struct vb2_buffer *vb)
> vpe_dbg(ctx->dev, "type: %d\n", vb->vb2_queue->type);
>
> q_data = get_q_data(ctx, vb->vb2_queue->type);
> + if (!q_data)
> + return -EINVAL;
> num_planes = q_data->nplanes;
>
> if (vb->vb2_queue->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
> @@ -2481,7 +2487,12 @@ static int vpe_probe(struct platform_device *pdev)
> mutex_init(&dev->dev_mutex);
>
> dev->res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> - "vpe_top");
> + "vpe_top");
> + if (!dev->res) {
> + dev_err(&pdev->dev, "missing 'vpe_top' resources data\n");
> + return -ENODEV;
> + }
> +
> /*
> * HACK: we get resource info from device tree in the form of a list of
> * VPE sub blocks, the driver currently uses only the base of vpe_top
> --
> 2.17.1
>