[FFmpeg-devel] [PATCH] avformat/utils: Ignore negative duration in codec_info_duration computation

Michael Niedermayer michael at niedermayer.cc
Sun Jul 4 00:02:16 EEST 2021


Fixes: signed integer overflow: -5994697211974418462 + -3255307777713450286 cannot be represented in type 'long'
Fixes: 35332/clusterfuzz-testcase-minimized-ffmpeg_dem_MATROSKA_fuzzer-5868035117285376

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavformat/utils.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index 0df14682a4..2974f3739e 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -3842,7 +3842,7 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
                     av_packet_unref(pkt1);
                 break;
             }
-            if (pkt->duration) {
+            if (pkt->duration > 0) {
                 if (avctx->codec_type == AVMEDIA_TYPE_SUBTITLE && pkt->pts != AV_NOPTS_VALUE && st->start_time != AV_NOPTS_VALUE && pkt->pts >= st->start_time
                     && (uint64_t)pkt->pts - st->start_time < INT64_MAX
                 ) {
-- 
2.17.1



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