From c517c3f4741b6897ea952d1fba199c93c5217cfe Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 14 Jun 2020 19:51:23 +0200 Subject: [PATCH] avformat/4xm: Check that a video stream was created before returning packets for it Fixes: assertion failure Fixes: 23434/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5227750851084288.fuzz Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/4xm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/libavformat/4xm.c b/libavformat/4xm.c index 5f0504b13e..6a227a0b0d 100644 --- a/libavformat/4xm.c +++ b/libavformat/4xm.c @@ -218,6 +218,7 @@ static int fourxm_read_header(AVFormatContext *s) fourxm->track_count = 0; fourxm->tracks = NULL; fourxm->fps = (AVRational){1,1}; + fourxm->video_stream_index = -1; /* skip the first 3 32-bit numbers */ avio_skip(pb, 12); @@ -326,6 +327,8 @@ static int fourxm_read_packet(AVFormatContext *s, * and size */ if (size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE - 8) return AVERROR_INVALIDDATA; + if (fourxm->video_stream_index < 0) + return AVERROR_INVALIDDATA; if ((ret = av_new_packet(pkt, size + 8)) < 0) return ret; pkt->stream_index = fourxm->video_stream_index;