[PATCH v2] media: vcodec: Fix potential array out-of-bounds in encoder queue_setup

[Eugen Hristev]

Hi Wei,

On 8/10/23 11:23, Wei Chen wrote:
> variable *nplanes is provided by user via system call argument. The
> possible value of q_data->fmt->num_planes is 1-3, while the value
> of *nplanes can be 1-8. The array access by index i can cause array
> out-of-bounds.
> 
> Fix this bug by checking *nplanes against the array size.
> 
> Fixes: 4e855a6efa54 ("[media] vcodec: mediatek: Add Mediatek V4L2 Video Encoder Driver")
> Signed-off-by: Wei Chen <harperchen1110 at gmail.com>
> Cc: stable at vger.kernel.org
> ---
> Changes in v2:
> - Add Fixes tag and CC stable email address
I guess stable needs to be added by the maintainer, not by the submitter

> - Change the title to be more expressive

Subject message should include mediatek I believe, as `media: vcodec:` 
does not reference the mediatek vcodec.

> 
>   drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c
> index 9ff439a50f53..9e8817863cb8 100644
> --- a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c
> +++ b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c
> @@ -821,6 +821,8 @@ static int vb2ops_venc_queue_setup(struct vb2_queue *vq,
>   		return -EINVAL;
>   
>   	if (*nplanes) {
> +		if (*nplanes != q_data->fmt->num_planes)
> +			return -EINVAL;

Have you run v4l2-compliance on the device to make sure nothing is broken ?

>   		for (i = 0; i < *nplanes; i++)
>   			if (sizes[i] < q_data->sizeimage[i])
>   				return -EINVAL;


Greetings,