From 96cf80609af6372d4e0d150b8a5ca517c072e897 Mon Sep 17 00:00:00 2001
From: Anton Khirnov <anton@khirnov.net>
Date: Wed, 27 Mar 2013 18:18:38 +0100
Subject: [PATCH] dfa: check for invalid access in decode_wdlt().

This can happen when the number of skipped lines is not consistent with
the number of coded lines.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
(cherry picked from commit 3623589edc7b1257bb45aa9e52c9631e133f22b6)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
---
 libavcodec/dfa.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/dfa.c b/libavcodec/dfa.c
index 9c80b3c4e8..563d7d5a1d 100644
--- a/libavcodec/dfa.c
+++ b/libavcodec/dfa.c
@@ -263,6 +263,8 @@ static int decode_wdlt(uint8_t *frame, int width, int height,
             segments = bytestream_get_le16(&src);
         }
         line_ptr = frame;
+        if (frame_end - frame < width)
+            return AVERROR_INVALIDDATA;
         frame += width;
         y++;
         while (segments--) {