[FFmpeg-devel] [PATCH 5/6] avformat/asfdec: Fix DoS due to lack of eof check

Michael Niedermayer michael at niedermayer.cc
Fri Aug 25 02:15:31 EEST 2017


From: 孙浩 and 张洪亮(望初) <tony.sh and wangchu.zhl at alibaba-inc.com>

Fixes: loop.asf

Found-by: Xiaohei and Wangchu from Alibaba Security Team
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavformat/asfdec_f.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/libavformat/asfdec_f.c b/libavformat/asfdec_f.c
index be09a92bd1..00dd5ec41d 100644
--- a/libavformat/asfdec_f.c
+++ b/libavformat/asfdec_f.c
@@ -749,13 +749,20 @@ 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++)
+    for (i = 0; i < name_len; i++) {
+        if (avio_feof(pb))
+            return AVERROR_INVALIDDATA;
         avio_r8(pb); // skip the name
+    }
+
 
     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;
-- 
2.14.1



More information about the ffmpeg-devel mailing list