From 5bd5c3108786bf69f108c55c375f1956f67ca7a4 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 31 May 2020 14:30:43 +0200 Subject: avformat/mlvdec: fail reading a packet with 0 streams Fixes: NULL pointer dereference Fixes: 22604/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5667739074297856.fuzz Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/mlvdec.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/libavformat/mlvdec.c b/libavformat/mlvdec.c index dae13cae53..03aed71024 100644 --- a/libavformat/mlvdec.c +++ b/libavformat/mlvdec.c @@ -393,10 +393,14 @@ static int read_packet(AVFormatContext *avctx, AVPacket *pkt) { MlvContext *mlv = avctx->priv_data; AVIOContext *pb; - AVStream *st = avctx->streams[mlv->stream_index]; + AVStream *st; int index, ret; unsigned int size, space; + if (!avctx->nb_streams) + return AVERROR_EOF; + + st = avctx->streams[mlv->stream_index]; if (mlv->pts >= st->duration) return AVERROR_EOF; -- cgit v1.2.3