matroskadec: move lace_size check up so it catches all code pathes

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/matroskadec.c

@@ -1975,6 +1975,11 @@ static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
 
     if (res == 0) {
         for (n = 0; n < laces; n++) {
+            if (lace_size[n] > size) {
+                av_log(matroska->ctx, AV_LOG_ERROR, "Invalid packet size\n");
+                break;
+            }
+
             if ((st->codec->codec_id == CODEC_ID_RA_288 ||
                  st->codec->codec_id == CODEC_ID_COOK ||
                  st->codec->codec_id == CODEC_ID_SIPR ||
@@ -2044,11 +2049,6 @@ static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
                 uint32_t pkt_size = lace_size[n];
                 uint8_t *pkt_data = data;
 
-                if (pkt_size > size) {
-                    av_log(matroska->ctx, AV_LOG_ERROR, "Invalid packet size\n");
-                    break;
-                }
-
                 if (encodings && encodings->scope & 1) {
                     offset = matroska_decode_buffer(&pkt_data,&pkt_size, track);
                     if (offset < 0)