h264: check for luma and chroma bit depth being equal

The decoder assumes a single bit depth for all the planes while
the specification allows different bit depths for luma and chroma.

Avoid the possible problems described in CVE-2013-2277

Conflicts:
	libavcodec/h264.c

1 files changed, 6 insertions, 0 deletions

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 739b9d2e51..ae2cf23a64 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -3867,6 +3867,12 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size){
             if(avctx->has_b_frames < 2)
                 avctx->has_b_frames= !s->low_delay;
 
+            if (h->sps.bit_depth_luma != h->sps.bit_depth_chroma) {
+                av_log_missing_feature(s->avctx,
+                    "Different bit depth between chroma and luma", 1);
+                return AVERROR_PATCHWELCOME;
+            }
+
             if (avctx->bits_per_raw_sample != h->sps.bit_depth_luma) {
                 if (h->sps.bit_depth_luma >= 8 && h->sps.bit_depth_luma <= 10) {
                     avctx->bits_per_raw_sample = h->sps.bit_depth_luma;