[FFmpeg-cvslog] avformat/utils: Check dts in update_initial_timestamps() more

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Jan 16 22:05:53 2021 +0100| [29851cb840c176d514573914799ca6c95f3f4e8e] | committer: Michael Niedermayer

avformat/utils: Check dts in update_initial_timestamps() more

Fixes: signed integer overflow: -9223372036853488158 - 90000000 cannot be represented in type 'long long'
Fixes: 26910/clusterfuzz-testcase-minimized-ffmpeg_dem_MPSUB_fuzzer-6696625298866176

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=29851cb840c176d514573914799ca6c95f3f4e8e
---

 libavformat/utils.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index 6f100294a1..1ec71691e5 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1106,6 +1106,7 @@ static void update_initial_timestamps(AVFormatContext *s, int stream_index,
         dts           == AV_NOPTS_VALUE ||
         st->cur_dts   == AV_NOPTS_VALUE ||
         st->cur_dts < INT_MIN + RELATIVE_TS_BASE ||
+        dts  < INT_MIN + (st->cur_dts - RELATIVE_TS_BASE) ||
         is_relative(dts))
         return;