From 605b047bcc48482dc8a356f56629da259fbddbf1 Mon Sep 17 00:00:00 2001
From: Anton Khirnov <anton@khirnov.net>
Date: Sun, 3 Feb 2013 08:42:02 +0100
Subject: rv10: improve buffer size check.

Check slice count and input buffer size before constructing a possibly
invalid pointer, not after.
---
 libavcodec/rv10.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

(limited to 'libavcodec')

diff --git a/libavcodec/rv10.c b/libavcodec/rv10.c
index 8cce6cf699..38abf7841a 100644
--- a/libavcodec/rv10.c
+++ b/libavcodec/rv10.c
@@ -659,11 +659,15 @@ static int rv10_decode_frame(AVCodecContext *avctx,
     if(!avctx->slice_count){
         slice_count = (*buf++) + 1;
         buf_size--;
+
+        if (!slice_count || buf_size <= 8 * slice_count) {
+            av_log(avctx, AV_LOG_ERROR, "Invalid slice count: %d.\n", slice_count);
+            return AVERROR_INVALIDDATA;
+        }
+
         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;
 
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