[FFmpeg-cvslog] avformat/utils: Check start/ end before computing duration in update_stream_timings()

[Michael Niedermayer]

ffmpeg | branch: release/3.0 | Michael Niedermayer <michael at niedermayer.cc> | Sat Dec  3 03:02:41 2016 +0100| [66e8f87ebc7897d0b7a92ff748c53481e990a670] | committer: Michael Niedermayer

avformat/utils: Check start/end before computing duration in update_stream_timings()

Fixes undefined behavior
Fixes: 637428.ogg

Found-by: Matt Wolenetz <wolenetz at google.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 90da187f1d334422477886a19eca3c1da29c59a7)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=66e8f87ebc7897d0b7a92ff748c53481e990a670
---

 libavformat/utils.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index 47e76ec..d368f0a 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -2402,11 +2402,14 @@ static void update_stream_timings(AVFormatContext *ic)
             if (ic->nb_programs) {
                 for (i = 0; i < ic->nb_programs; i++) {
                     p = ic->programs[i];
-                    if (p->start_time != AV_NOPTS_VALUE && p->end_time > p->start_time)
+                    if (p->start_time != AV_NOPTS_VALUE &&
+                        p->end_time > p->start_time &&
+                        p->end_time - (uint64_t)p->start_time <= INT64_MAX)
                         duration = FFMAX(duration, p->end_time - p->start_time);
                 }
-            } else
+            } else if (end_time >= start_time && end_time - (uint64_t)start_time <= INT64_MAX) {
                 duration = FFMAX(duration, end_time - start_time);
+            }
         }
     }
     if (duration != INT64_MIN && duration > 0 && ic->duration == AV_NOPTS_VALUE) {