[SCM] libav/experimental: pgssubdec: Check RLE size before copying

[siretart at users.alioth.debian.org]

The following commit has been merged in the experimental branch:
commit d98e6c5d5d80c1dfe0c30f2e73d41a3aea0b920d
Author: Michael Niedermayer <michaelni at gmx.at>
Date:   Wed Jul 30 21:31:19 2014 -0400

    pgssubdec: Check RLE size before copying
    
    Make sure the buffer size does not exceed the expected
    RLE size.
    
    Prevent an out of array bound write.
    
    Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
    Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
    Bug-Id: CVE-2013-0852
    
    Signed-off-by: Luca Barbato <lu_zero at gentoo.org>

diff --git a/libavcodec/pgssubdec.c b/libavcodec/pgssubdec.c
index 1cafd9f..6217c40 100644
--- a/libavcodec/pgssubdec.c
+++ b/libavcodec/pgssubdec.c
@@ -275,6 +275,13 @@ static int parse_object_segment(AVCodecContext *avctx,
     /* Decode rle bitmap length, stored size includes width/height data */
     rle_bitmap_len = bytestream_get_be24(&buf) - 2*2;
 
+    if (buf_size > rle_bitmap_len) {
+        av_log(avctx, AV_LOG_ERROR,
+               "Buffer dimension %d larger than the expected RLE data %d\n",
+               buf_size, rle_bitmap_len);
+        return AVERROR_INVALIDDATA;
+    }
+
     /* Get bitmap dimensions from data */
     width  = bytestream_get_be16(&buf);
     height = bytestream_get_be16(&buf);

-- 
Libav/FFmpeg packaging