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@gmail.com Cc: stable@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,

Hi,

Le jeudi 10 août 2023 à 08:23 +0000, Wei Chen a écrit :

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@gmail.com Cc: stable@vger.kernel.org

---

Changes in v2:

• Add Fixes tag and CC stable email address
• Change the title to be more expressive

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;
  

I don't think the claim really exists. For this driver, when *nplane is set, it will be:

case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE: requested_planes = f->fmt.pix_mp.num_planes; if (requested_planes == 0 || requested_planes > VIDEO_MAX_PLANES) return -EINVAL; for (i = 0; i < requested_planes; i++) requested_sizes[i] = f->fmt.pix_mp.plane_fmt[i].sizeimage; break;

Or the value the driver have set it in the previous call with *nplane == 0. So unless there is a bug, this should not happen, and more importantly, the core should not let that happen, meaning it should not be driver jobs to validate this.

my 2 cents, Nicolas

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