rv10/20: Fix a buffer overread caused by losing track of the remaining buffer size.

Message ID 20120302173305.0A4685E07E@aruru.libav.org
State New
Headers show

Commit Message

Janne Grunau March 2, 2012, 5:33 p.m.
Module: libav
Branch: master
Commit: 2f6528537fdd88820f3a4683d5e595d7b3a62689

Author:    Alex Converse <alex.converse@gmail.com>
Committer: Alex Converse <alex.converse@gmail.com>
Date:      Thu Mar  1 14:07:22 2012 -0800

rv10/20: Fix a buffer overread caused by losing track of the remaining buffer size.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

---

 libavcodec/rv10.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

Patch

diff --git a/libavcodec/rv10.c b/libavcodec/rv10.c
index 6e6516f..5dd08e9 100644
--- a/libavcodec/rv10.c
+++ b/libavcodec/rv10.c
@@ -642,8 +642,12 @@  static int rv10_decode_frame(AVCodecContext *avctx,
 
     if(!avctx->slice_count){
         slice_count = (*buf++) + 1;
+        buf_size--;
         slices_hdr = buf + 4;
         buf += 8 * slice_count;
+        buf_size -= 8 * slice_count;
+        if (buf_size <= 0)
+            return AVERROR_INVALIDDATA;
     }else
         slice_count = avctx->slice_count;
 
@@ -689,7 +693,7 @@  static int rv10_decode_frame(AVCodecContext *avctx,
         s->current_picture_ptr= NULL; //so we can detect if frame_end wasnt called (find some nicer solution...)
     }
 
-    return buf_size;
+    return avpkt->size;
 }
 
 AVCodec ff_rv10_decoder = {