From d423dd72be451462c6fb1cbbe313bed0194001ab Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Fri, 3 Oct 2014 22:50:45 +0200
Subject: [PATCH] smc: fix the bounds check

Fixes invalid writes when there are more blocks in a run than total
remaining blocks.

CC: libav-stable@libav.org
Bug-ID: CVE-2014-8548
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Anton Khirnov <anton@khirnov.net>
---
 libavcodec/smc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/smc.c b/libavcodec/smc.c
index 46903ab2af..c6541da843 100644
--- a/libavcodec/smc.c
+++ b/libavcodec/smc.c
@@ -70,7 +70,7 @@ typedef struct SmcContext {
         row_ptr += stride * 4; \
     } \
     total_blocks--; \
-    if (total_blocks < 0) \
+    if (total_blocks < !!n_blocks) \
     { \
         av_log(s->avctx, AV_LOG_INFO, "warning: block counter just went negative (this should not happen)\n"); \
         return; \