[PATCH 07/10] staging: media: cedrus: validate VP8 frame size

[Jernej Skrabec <jernej.skrabec@gmail.com>]

A VP8 key frame can change the frame size. If userspace doesn't
reallocate the capture buffers, the hardware writes and reads past the
buffers, which shows up as IOMMU page faults and decode timeouts.

Check the frame size in try_ctrl, like for the H.264 and HEVC SPS.

Fixes: 3c39a16d30d8 ("media: cedrus: Add support for VP8 decoding")
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
 drivers/staging/media/sunxi/cedrus/cedrus.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c b/drivers/staging/media/sunxi/cedrus/cedrus.c
index 45deebddb630..756243795de8 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus.c
@@ -77,6 +77,11 @@ static int cedrus_try_ctrl(struct v4l2_ctrl *ctrl)
 					  (sps->pic_width_in_mbs_minus1 + 1) * 16,
 					  height))
 			return -EINVAL;
+	} else if (ctrl->id == V4L2_CID_STATELESS_VP8_FRAME) {
+		const struct v4l2_ctrl_vp8_frame *frame = ctrl->p_new.p_vp8_frame;
+
+		if (cedrus_check_pic_size(ctx, frame->width, frame->height))
+			return -EINVAL;
 	} else if (ctrl->id == V4L2_CID_STATELESS_HEVC_SPS) {
 		const struct v4l2_ctrl_hevc_sps *sps = ctrl->p_new.p_hevc_sps;
 		unsigned int bit_depth, max_depth;
@@ -270,6 +275,7 @@ static const struct cedrus_control cedrus_controls[] = {
 	{
 		.cfg = {
 			.id	= V4L2_CID_STATELESS_VP8_FRAME,
+			.ops	= &cedrus_ctrl_ops,
 		},
 		.capabilities	= CEDRUS_CAPABILITY_VP8_DEC,
 	},
-- 
2.43.0