From 460bcdcd8447f0de870ed482f5efdca4c191b422 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 (cherry picked from commit c517c3f4741b6897ea952d1fba199c93c5217cfe) 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 8756df66a9..d94298a66e 100644 --- a/libavformat/4xm.c +++ b/libavformat/4xm.c @@ -209,6 +209,7 @@ 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); @@ -314,6 +315,8 @@ static int fourxm_read_packet(AVFormatContext *s, case cfr2_TAG: /* allocate 8 more bytes than 'size' to account for fourcc * and size */ + if (fourxm->video_stream_index < 0) + return AVERROR_INVALIDDATA; if (size + 8 < size || av_new_packet(pkt, size + 8)) return AVERROR(EIO); pkt->stream_index = fourxm->video_stream_index;