From 4c0dda2b3f45471faa233c62205e712fb072a76b Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Tue, 22 Sep 2009 22:44:56 +0000
Subject: [PATCH] Check codec_id and codec_type in avcodec_open(), based on
 43_codec_type_mismatch.patch from chrome This is said to be able to lead to a
 stack based buffer overflow.

Originally committed as revision 19973 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/utils.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 1ec039e5e9..c31608df99 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -481,7 +481,10 @@ int attribute_align_arg avcodec_open(AVCodecContext *avctx, AVCodec *codec)
     }
 
     avctx->codec = codec;
-    avctx->codec_id = codec->id;
+    if(avctx->codec_id != codec->id || avctx->codec_type != codec->type){
+        av_log(avctx, AV_LOG_ERROR, "codec type or id mismatches\n");
+        goto end;
+    }
     avctx->frame_number = 0;
     if(avctx->codec->init){
         ret = avctx->codec->init(avctx);