From ffe4851e2359e17c4406ab05e2e31fc7ef68de95 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 9 Jun 2021 21:10:32 +0200 Subject: avformat/utils: Avoid overflow in codec_info_duration computation for subtitles Fixes: signed integer overflow: 9223126845747118112 - -2594073385365397472 cannot be represented in type 'long' Fixes: 34936/clusterfuzz-testcase-minimized-ffmpeg_dem_MATROSKA_fuzzer-6739888002170880 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/utils.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/libavformat/utils.c b/libavformat/utils.c index ac150406ff..0df14682a4 100644 --- a/libavformat/utils.c +++ b/libavformat/utils.c @@ -3843,7 +3843,9 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options) break; } if (pkt->duration) { - if (avctx->codec_type == AVMEDIA_TYPE_SUBTITLE && pkt->pts != AV_NOPTS_VALUE && st->start_time != AV_NOPTS_VALUE && pkt->pts >= st->start_time) { + 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 + ) { st->internal->info->codec_info_duration = FFMIN(pkt->pts - st->start_time, st->internal->info->codec_info_duration + pkt->duration); } else st->internal->info->codec_info_duration += pkt->duration; -- cgit v1.2.3