[FFmpeg-cvslog] avformat/matroskadec: Use rounded down duration in get_cue_desc() check

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Mar 10 23:24:49 2022 +0100| [bd3a03db9aef72ee36a7cc964171e9f52967f4bc] | committer: Michael Niedermayer

avformat/matroskadec: Use rounded down duration in get_cue_desc() check

Floating point is evil, it would be better if duration was not a double

Fixes: Infinite loop
Fixes: 45123/clusterfuzz-testcase-minimized-ffmpeg_dem_WEBM_DASH_MANIFEST_fuzzer-6725052291219456

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=bd3a03db9aef72ee36a7cc964171e9f52967f4bc
---

 libavformat/matroskadec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 1a6606aa91..c6709a267b 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -4013,7 +4013,8 @@ static CueDesc get_cue_desc(AVFormatContext *s, int64_t ts, int64_t cues_start)
     CueDesc cue_desc;
     int i;
 
-    if (ts >= matroska->duration * matroska->time_scale) return (CueDesc) {-1, -1, -1, -1};
+    if (ts >= (int64_t)(matroska->duration * matroska->time_scale))
+        return (CueDesc) {-1, -1, -1, -1};
     for (i = 1; i < nb_index_entries; i++) {
         if (index_entries[i - 1].timestamp * matroska->time_scale <= ts &&
             index_entries[i].timestamp * matroska->time_scale > ts) {