From 20be3ea442abafbdc4d8288a549c302a306bc63c Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Wed, 4 Feb 2015 20:13:18 +0100
Subject: [PATCH] avcodec/mjpegdec: Check escape sequence validity

Fixes assertion failure
Fixes: asan_heap-oob_1c1a4ea_1242_cov_2274415971_TESTcmyk.jpg

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
 libavcodec/mjpegdec.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index a2a93c1266..f04b603437 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -1631,6 +1631,10 @@ int ff_mjpeg_find_marker(MJpegDecodeContext *s,
             put_bits(&pb, 8, x);
             if (x == 0xFF) {
                 x = src[b++];
+                if (x & 0x80) {
+                    av_log(s->avctx, AV_LOG_WARNING, "Invalid escape sequence\n");
+                    x &= 0x7f;
+                }
                 put_bits(&pb, 7, x);
                 bit_count--;
             }