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

[Wei Chen]

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
- 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;
 		for (i = 0; i < *nplanes; i++)
 			if (sizes[i] < q_data->sizeimage[i])
 				return -EINVAL;
-- 
2.25.1