From 69fb605ad5e0f1384ca4d06d38ce0f1b6c8c286d Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 24 Jan 2013 02:51:12 +0100 Subject: [PATCH] mpc8: check stream count before accessing stream 1. Fixes null pointer dereference Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer --- libavformat/mpc8.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/libavformat/mpc8.c b/libavformat/mpc8.c index 011c7c8e64..73f805711d 100644 --- a/libavformat/mpc8.c +++ b/libavformat/mpc8.c @@ -139,6 +139,11 @@ static void mpc8_parse_seektable(AVFormatContext *s, int64_t off) int i, t, seekd; GetBitContext gb; + if (s->nb_streams<=0) { + av_log(s, AV_LOG_ERROR, "cannot parse stream table before stream header\n"); + return; + } + avio_seek(s->pb, off, SEEK_SET); mpc8_get_chunk_header(s->pb, &tag, &size); if(tag != TAG_SEEKTABLE){