[FFmpeg-devel] [PATCH 1/3] avformat/utils: Check rfps_duration_sum for overflow

[Michael Niedermayer]

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

diff --git a/libavformat/utils.c b/libavformat/utils.c
index 886cd6fd83..2e8b2e8a0b 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -3347,8 +3347,10 @@ 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;
-- 
2.22.0