[FFmpeg-cvslog] avformat/utils: Extend overflow check in dts wrap in compute_pkt_fields()

[Michael Niedermayer]

ffmpeg | branch: release/4.4 | Michael Niedermayer <michael at niedermayer.cc> | Tue Feb  2 17:29:23 2021 +0100| [9b25cf8b061136381852a85ca1bb5ec2c6fda9f4] | committer: Michael Niedermayer

avformat/utils: Extend overflow check in dts wrap in compute_pkt_fields()

Fixes: signed integer overflow: -9223372032574480351 - 4294967296 cannot be represented in type 'long long'
Fixes: 30022/clusterfuzz-testcase-minimized-ffmpeg_dem_KUX_fuzzer-5568610275819520

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit b37ff29e0e093b15585e9fb44bbd82bdf14b5230)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9b25cf8b061136381852a85ca1bb5ec2c6fda9f4
---

 libavformat/utils.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index 1066b54ffd..a65d14234a 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1275,7 +1275,7 @@ static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
         presentation_delayed = 1;
 
     if (pkt->pts != AV_NOPTS_VALUE && pkt->dts != AV_NOPTS_VALUE &&
-        st->pts_wrap_bits < 63 && pkt->dts > INT64_MIN + (1LL << (st->pts_wrap_bits - 1)) &&
+        st->pts_wrap_bits < 63 && pkt->dts > INT64_MIN + (1LL << st->pts_wrap_bits) &&
         pkt->dts - (1LL << (st->pts_wrap_bits - 1)) > pkt->pts) {
         if (is_relative(st->cur_dts) || pkt->dts - (1LL<<(st->pts_wrap_bits - 1)) > st->cur_dts) {
             pkt->dts -= 1LL << st->pts_wrap_bits;