[PATCH v2] media: imx-jpeg: Prevent decoding NV12M jpegs into single-planar buffers

[Mirela Rabulea]

If the application queues an NV12M jpeg as output buffer, but then
queues a single planar capture buffer, the kernel will crash with
"Unable to handle kernel NULL pointer dereference" in mxc_jpeg_addrs,
prevent this by finishing the job with error.

Signed-off-by: Mirela Rabulea <mirela.rabulea@xxxxxxxxxxx>
---
Changed in v2:
  Simplified and generalized the condition check for mismatching number of planes (feedback from Ming)
  Updated error message

 drivers/media/platform/imx-jpeg/mxc-jpeg.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/media/platform/imx-jpeg/mxc-jpeg.c b/drivers/media/platform/imx-jpeg/mxc-jpeg.c
index 4ca96cf9def7..b249c1bbfac8 100644
--- a/drivers/media/platform/imx-jpeg/mxc-jpeg.c
+++ b/drivers/media/platform/imx-jpeg/mxc-jpeg.c
@@ -947,6 +947,12 @@ static void mxc_jpeg_device_run(void *priv)
 	v4l2_m2m_buf_copy_metadata(src_buf, dst_buf, true);
 
 	jpeg_src_buf = vb2_to_mxc_buf(&src_buf->vb2_buf);
+	if (q_data_cap->fmt->colplanes != dst_buf->vb2_buf.num_planes) {
+		dev_err(dev, "Capture format %s has %d planes, but capture buffer has %d planes\n",
+			q_data_cap->fmt->name, q_data_cap->fmt->colplanes,
+			dst_buf->vb2_buf.num_planes);
+		jpeg_src_buf->jpeg_parse_error = true;
+	}
 	if (jpeg_src_buf->jpeg_parse_error) {
 		jpeg->slot_data[ctx->slot].used = false;
 		v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
-- 
2.25.1