From 02699490c14e86105104940c009953081f69432c Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 8 Feb 2022 20:00:53 +0100 Subject: [PATCH] avformat/demux: Make read_frame_internal() return AVERREOR(EAGAIN) on stuck empty input parser Fixes: read_frame_internal() which does not return even though both demuxer and parser do return Fixes: 43717/clusterfuzz-testcase-minimized-ffmpeg_IO_DEMUXER_fuzzer-5206008287330304 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/demux.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/libavformat/demux.c b/libavformat/demux.c index 1620716716..57720f4311 100644 --- a/libavformat/demux.c +++ b/libavformat/demux.c @@ -1235,11 +1235,15 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt) FFFormatContext *const si = ffformatcontext(s); int ret, got_packet = 0; AVDictionary *metadata = NULL; + int empty = 0; while (!got_packet && !si->parse_queue.head) { AVStream *st; FFStream *sti; + if (empty > 1) + return AVERROR(EAGAIN); + /* read next packet */ ret = ff_read_packet(s, pkt); if (ret < 0) { @@ -1330,6 +1334,8 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt) } got_packet = 1; } else if (st->discard < AVDISCARD_ALL) { + if (pkt->size == 0) + empty ++; if ((ret = parse_packet(s, pkt, pkt->stream_index, 0)) < 0) return ret; st->codecpar->sample_rate = sti->avctx->sample_rate;