[FFmpeg-devel] [PATCH 7/8] Reject block size changes in the shorten decoder.

[fenrir at elivagar.org]

From: Laurent Aimar <fenrir at videolan.org>

---
 libavcodec/shorten.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/libavcodec/shorten.c b/libavcodec/shorten.c
index b39fcbd..966584d 100644
--- a/libavcodec/shorten.c
+++ b/libavcodec/shorten.c
@@ -482,9 +482,14 @@ static int shorten_decode_frame(AVCodecContext *avctx,
             case FN_BITSHIFT:
                 s->bitshift = get_ur_golomb_shorten(&s->gb, BITSHIFTSIZE);
                 break;
-            case FN_BLOCKSIZE:
-                s->blocksize = get_uint(s, av_log2(s->blocksize));
+            case FN_BLOCKSIZE: {
+                int blocksize = get_uint(s, av_log2(s->blocksize));
+                if (blocksize != s->blocksize) {
+                    av_log(avctx, AV_LOG_ERROR, "block size changes are not supported\n");
+                    return AVERROR_PATCHWELCOME;
+                }
                 break;
+            }
             case FN_QUIT:
                 *data_size = 0;
                 return buf_size;
-- 
1.7.2.5