[FFmpeg-cvslog] avformat/r3d: Check samples before computing duration

[Michael Niedermayer]

ffmpeg | branch: release/4.3 | Michael Niedermayer <michael at niedermayer.cc> | Wed Feb 10 23:21:53 2021 +0100| [32454c40fa657b431010d35a282276cea2389a2b] | committer: Michael Niedermayer

avformat/r3d: Check samples before computing duration

Fixes: signed integer overflow: -4611686024827895807 + -4611686016279904256 cannot be represented in type 'long'
Fixes: 30161/clusterfuzz-testcase-minimized-ffmpeg_dem_R3D_fuzzer-5694406713802752

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 7a2aa5dc2af6c4fc66aaedd341b0886fbc746f0d)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=32454c40fa657b431010d35a282276cea2389a2b
---

 libavformat/r3d.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavformat/r3d.c b/libavformat/r3d.c
index 7aa0c5a2c3..edd80ab4fa 100644
--- a/libavformat/r3d.c
+++ b/libavformat/r3d.c
@@ -322,7 +322,8 @@ static int r3d_read_reda(AVFormatContext *s, AVPacket *pkt, Atom *atom)
 
     pkt->stream_index = 1;
     pkt->dts = dts;
-    if (st->codecpar->sample_rate)
+
+    if (st->codecpar->sample_rate && samples > 0)
         pkt->duration = av_rescale(samples, st->time_base.den, st->codecpar->sample_rate);
     av_log(s, AV_LOG_TRACE, "pkt dts %"PRId64" duration %"PRId64" samples %d sample rate %d\n",
             pkt->dts, pkt->duration, samples, st->codecpar->sample_rate);