[FFmpeg-cvslog] mpeg12: do not decode extradata more than once.

Anton Khirnov git at videolan.org
Wed Feb 13 13:38:52 CET 2013


ffmpeg | branch: release/0.5 | Anton Khirnov <anton at khirnov.net> | Thu Dec 13 17:53:31 2012 +0100| [0b25c3b67cef73ab1370db99da906ebc215a3c72] | committer: Reinhard Tartler

mpeg12: do not decode extradata more than once.

Fixes CVE-2012-2803.

(cherry picked from commit 582368626188c070d4300913c6da5efa4c24cfb2)
(cherry picked from commit 301761792a693a1f3303a2af34a0fb066a03c10c)

Conflicts:

	libavcodec/mpeg12.c

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0b25c3b67cef73ab1370db99da906ebc215a3c72
---

 libavcodec/mpeg12.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index 9e67ee5..95d1282 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -1163,6 +1163,7 @@ typedef struct Mpeg1Context {
     int save_width, save_height;
     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
 
+    int extradata_decoded;
 } Mpeg1Context;
 
 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
@@ -2299,8 +2300,10 @@ static int mpeg_decode_frame(AVCodecContext *avctx,
 
     s->slice_count= 0;
 
-    if(avctx->extradata && !avctx->frame_number)
+    if (avctx->extradata && !s->extradata_decoded) {
         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
+        s->extradata_decoded = 1;
+    }
 
     return decode_chunks(avctx, picture, data_size, buf, buf_size);
 }



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