From cdf76ca5729e9e88d194a67ec84d1eb93c6e1820 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 8 Nov 2020 00:17:09 +0100 Subject: [PATCH] avformat/lvfdec: Check stream_index before use Fixes: assertion failure Fixes: 26905/clusterfuzz-testcase-minimized-ffmpeg_dem_LVF_fuzzer-5724267599364096.fuzz Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Reviewed-by: Paul B Mahol Signed-off-by: Michael Niedermayer (cherry picked from commit b1d99ab14f2fd273e678dcb618dabfb38aab91b6) Signed-off-by: Michael Niedermayer --- libavformat/lvfdec.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/libavformat/lvfdec.c b/libavformat/lvfdec.c index 8b8d6f01b9..4c87728def 100644 --- a/libavformat/lvfdec.c +++ b/libavformat/lvfdec.c @@ -106,6 +106,7 @@ static int lvf_read_packet(AVFormatContext *s, AVPacket *pkt) unsigned size, flags, timestamp, id; int64_t pos; int ret, is_video = 0; + int stream_index; pos = avio_tell(s->pb); while (!avio_feof(s->pb)) { @@ -121,12 +122,15 @@ static int lvf_read_packet(AVFormatContext *s, AVPacket *pkt) case MKTAG('0', '1', 'w', 'b'): if (size < 8) return AVERROR_INVALIDDATA; + stream_index = is_video ? 0 : 1; + if (stream_index >= s->nb_streams) + return AVERROR_INVALIDDATA; timestamp = avio_rl32(s->pb); flags = avio_rl32(s->pb); ret = av_get_packet(s->pb, pkt, size - 8); if (flags & (1 << 12)) pkt->flags |= AV_PKT_FLAG_KEY; - pkt->stream_index = is_video ? 0 : 1; + pkt->stream_index = stream_index; pkt->pts = timestamp; pkt->pos = pos; return ret;