[FFmpeg-cvslog] rpza: limit the number of blocks to the total remaining blocks in the frame

[Anton Khirnov]

ffmpeg | branch: release/1.1 | Anton Khirnov <anton at khirnov.net> | Thu Nov 28 10:54:35 2013 +0100| [d2a065437a96b5ab73f15362fe3d5cde3c61f160] | committer: Luca Barbato

rpza: limit the number of blocks to the total remaining blocks in the frame

Fixes invalid writes.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable at libav.org
(cherry picked from commit 77bb0004bbe18f1498cfecdc68db5f10808b6599)
Signed-off-by: Luca Barbato <lu_zero at gentoo.org>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d2a065437a96b5ab73f15362fe3d5cde3c61f160
---

 libavcodec/rpza.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/rpza.c b/libavcodec/rpza.c
index 59b15c6..63ea706 100644
--- a/libavcodec/rpza.c
+++ b/libavcodec/rpza.c
@@ -38,6 +38,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "libavutil/common.h"
 #include "libavutil/internal.h"
 #include "libavutil/intreadwrite.h"
 #include "avcodec.h"
@@ -126,6 +127,8 @@ static void rpza_decode_stream(RpzaContext *s)
             }
         }
 
+        n_blocks = FFMIN(n_blocks, total_blocks);
+
         switch (opcode & 0xe0) {
 
         /* Skip blocks */