[SCM] libav/master: h264: check buffer size before accessing it

[siretart at users.alioth.debian.org]

The following commit has been merged in the master branch:
commit af40847681b978441fdd25276685414f9e17820a
Author: Anton Khirnov <anton at khirnov.net>
Date:   Fri Nov 15 10:15:24 2013 +0100

    h264: check buffer size before accessing it
    
    Fixes invalid reads.
    Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
    CC:libav-stable at libav.org

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index d6d3d42..20fa82c 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -3941,7 +3941,7 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
                 s->workaround_bugs |= FF_BUG_TRUNCATED;
 
             if (!(s->workaround_bugs & FF_BUG_TRUNCATED))
-                while (ptr[dst_length - 1] == 0 && dst_length > 0)
+                while (dst_length > 0 && ptr[dst_length - 1] == 0)
                     dst_length--;
             bit_length = !dst_length ? 0
                                      : (8 * dst_length -

-- 
Libav/FFmpeg packaging