[FFmpeg-cvslog] avformat/concatdec: Check in/outpoint for overflow

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Sep 30 19:11:34 2023 +0200| [dedc78b4b5bdab869f3038798334639d617d2309] | committer: Michael Niedermayer

avformat/concatdec: Check in/outpoint for overflow

Fixes: signed integer overflow: 91542414454000000 - -9154241494546000000 cannot be represented in type 'long'
Fixes: 51896/clusterfuzz-testcase-minimized-ffmpeg_dem_CONCAT_fuzzer-4739147999084544

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=dedc78b4b5bdab869f3038798334639d617d2309
---

 libavformat/concatdec.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavformat/concatdec.c b/libavformat/concatdec.c
index 5d4f67d0ac..114b6c6564 100644
--- a/libavformat/concatdec.c
+++ b/libavformat/concatdec.c
@@ -667,7 +667,9 @@ static int concat_read_header(AVFormatContext *avf)
         else
             time = cat->files[i].start_time;
         if (cat->files[i].user_duration == AV_NOPTS_VALUE) {
-            if (cat->files[i].inpoint == AV_NOPTS_VALUE || cat->files[i].outpoint == AV_NOPTS_VALUE)
+            if (cat->files[i].inpoint == AV_NOPTS_VALUE || cat->files[i].outpoint == AV_NOPTS_VALUE ||
+                cat->files[i].outpoint - (uint64_t)cat->files[i].inpoint != av_sat_sub64(cat->files[i].outpoint, cat->files[i].inpoint)
+            )
                 break;
             cat->files[i].user_duration = cat->files[i].outpoint - cat->files[i].inpoint;
         }