[FFmpeg-cvslog] avformat/asfdec_f: Check name_len for overflow

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Oct 15 22:04:56 2020 +0200| [0d088a47ca0243576078f109fff20617d1fac382] | committer: Michael Niedermayer

avformat/asfdec_f: Check name_len for overflow

Fixes: signed integer overflow: -1172299744 * 2 cannot be represented in type 'int'
Fixes: 26258/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5672758488596480

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0d088a47ca0243576078f109fff20617d1fac382
---

 libavformat/asfdec_f.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavformat/asfdec_f.c b/libavformat/asfdec_f.c
index 103155e9e7..ff9107d73f 100644
--- a/libavformat/asfdec_f.c
+++ b/libavformat/asfdec_f.c
@@ -769,6 +769,8 @@ static int asf_read_marker(AVFormatContext *s, int64_t size)
         avio_rl32(pb);             // send time
         avio_rl32(pb);             // flags
         name_len = avio_rl32(pb);  // name length
+        if ((unsigned)name_len > INT_MAX / 2)
+            return AVERROR_INVALIDDATA;
         if ((ret = avio_get_str16le(pb, name_len * 2, name,
                                     sizeof(name))) < name_len)
             avio_skip(pb, name_len - ret);