[FFmpeg-cvslog] avformat/sbgdec: Check that end is not before start

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Nov 10 00:04:50 2020 +0100| [9ef60a66f1f155605049402415bd901c8baf1a24] | committer: Michael Niedermayer

avformat/sbgdec: Check that end is not before start

Fixes: signed integer overflow: -9223372036854775808 + -5279949906739200 cannot be represented in type 'long'
Fixes: 26908/clusterfuzz-testcase-minimized-ffmpeg_dem_SBG_fuzzer-6329610851319808

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=9ef60a66f1f155605049402415bd901c8baf1a24
---

 libavformat/sbgdec.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavformat/sbgdec.c b/libavformat/sbgdec.c
index 4d6ae7abc5..f56eb9ff59 100644
--- a/libavformat/sbgdec.c
+++ b/libavformat/sbgdec.c
@@ -1416,6 +1416,11 @@ static av_cold int sbg_read_header(AVFormatContext *avf)
     if (r < 0)
         goto fail;
 
+    if (script.end_ts != AV_NOPTS_VALUE && script.end_ts < script.start_ts) {
+        r = AVERROR_INVALIDDATA;
+        goto fail;
+    }
+
     st = avformat_new_stream(avf, NULL);
     if (!st)
         return AVERROR(ENOMEM);