From 618a9bea65112a27a106e02ada3ae475cc8ac1ac Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 23 Feb 2020 09:27:27 +0100 Subject: [PATCH] avformat/mvdec: Check stream numbers Fixes: null pointer dereference Fixes: 20768/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5638648978735104.fuzz Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Reviewed-by: Andreas Rheinhardt Signed-off-by: Michael Niedermayer --- libavformat/mvdec.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c index f9f7e38137..64166a84b1 100644 --- a/libavformat/mvdec.c +++ b/libavformat/mvdec.c @@ -363,6 +363,12 @@ static int mv_read_header(AVFormatContext *avctx) if ((ret = read_table(avctx, NULL, parse_global_var)) < 0) return ret; + if (mv->nb_audio_tracks < 0 || mv->nb_video_tracks < 0 || + (mv->nb_audio_tracks == 0 && mv->nb_video_tracks == 0)) { + av_log(avctx, AV_LOG_ERROR, "Stream count is invalid.\n"); + return AVERROR_INVALIDDATA; + } + if (mv->nb_audio_tracks > 1) { avpriv_request_sample(avctx, "Multiple audio streams support"); return AVERROR_PATCHWELCOME;