[FFmpeg-cvslog] avformat/utils: Check rfps_duration_sum for overflow

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Jul  4 23:01:19 2019 +0200| [5c46fdf305caac8bf2f270e69e60ae3d614df468] | committer: Michael Niedermayer

avformat/utils: Check rfps_duration_sum for overflow

Fixes: signed integer overflow: 9151595917793558550 + 297519050751678697 cannot be represented in type 'long'
Fixes: 15496/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5722866475073536

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=5c46fdf305caac8bf2f270e69e60ae3d614df468
---

 libavformat/utils.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index 180df782f0..6c6f4e1bd1 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -3348,8 +3348,10 @@ int ff_rfps_add_frame(AVFormatContext *ic, AVStream *st, int64_t ts)
                 }
             }
         }
-        st->info->duration_count++;
-        st->info->rfps_duration_sum += duration;
+        if (st->info->rfps_duration_sum <= INT64_MAX - duration) {
+            st->info->duration_count++;
+            st->info->rfps_duration_sum += duration;
+        }
 
         if (st->info->duration_count % 10 == 0) {
             int n = st->info->duration_count;