From f94517934bf0ff2510f472fa2bc4cd362951109c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=AD=99=E6=B5=A9=20and=20=E5=BC=A0=E6=B4=AA=E4=BA=AE=28?=
 =?UTF-8?q?=E6=9C=9B=E5=88=9D=29?= <tony.sh and wangchu.zhl@alibaba-inc.com>
Date: Fri, 25 Aug 2017 12:37:25 +0200
Subject: [PATCH] avformat/asfdec: Fix DoS due to lack of eof check

Fixes: loop.asf

Found-by: Xiaohei and Wangchu from Alibaba Security Team
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 7f9ec5593e04827249e7aeb466da06a98a0d7329)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavformat/asfdec_f.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git libavformat/asfdec_f.c libavformat/asfdec_f.c
index b973eff96e4..2cacafe50d5 100644
--- external/FFmpeg/libavformat/asfdec_f.c
+++ external/FFmpeg/libavformat/asfdec_f.c
@@ -749,13 +749,15 @@ static int asf_read_marker(AVFormatContext *s, int64_t size)
     count = avio_rl32(pb);    // markers count
     avio_rl16(pb);            // reserved 2 bytes
     name_len = avio_rl16(pb); // name length
-    for (i = 0; i < name_len; i++)
-        avio_r8(pb); // skip the name
+    avio_skip(pb, name_len);
 
     for (i = 0; i < count; i++) {
         int64_t pres_time;
         int name_len;
 
+        if (avio_feof(pb))
+            return AVERROR_INVALIDDATA;
+
         avio_rl64(pb);             // offset, 8 bytes
         pres_time = avio_rl64(pb); // presentation time
         pres_time -= asf->hdr.preroll * 10000;
