matroskadec: Verify realaudio codec parameters

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/matroskadec.c

@@ -1622,6 +1622,10 @@ static int matroska_read_header(AVFormatContext *s)
             track->audio.sub_packet_h    = avio_rb16(&b);
             track->audio.frame_size      = avio_rb16(&b);
             track->audio.sub_packet_size = avio_rb16(&b);
+            if (flavor <= 0 || track->audio.coded_framesize <= 0 ||
+                track->audio.sub_packet_h <= 0 || track->audio.frame_size <= 0 ||
+                track->audio.sub_packet_size <= 0)
+                return AVERROR_INVALIDDATA;
             track->audio.buf = av_malloc(track->audio.frame_size * track->audio.sub_packet_h);
             if (codec_id == AV_CODEC_ID_RA_288) {
                 st->codec->block_align = track->audio.coded_framesize;