validate uv block size when reading partition

Change-Id: I74fc5f1a7bab3128cdd49441b83ec3a25aee65ca

vp9/decoder/vp9_decodeframe.c

@@ -410,13 +410,17 @@ static void decode_partition(VP9_COMMON *const cm, MACROBLOCKD *const xd,
                              vp9_reader* r, BLOCK_SIZE bsize) {
   const int hbs = num_8x8_blocks_wide_lookup[bsize] / 2;
   PARTITION_TYPE partition;
-  BLOCK_SIZE subsize;
+  BLOCK_SIZE subsize, uv_subsize;
 
   if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols)
     return;
 
   partition = read_partition(cm, xd, hbs, mi_row, mi_col, bsize, r);
   subsize = get_subsize(bsize, partition);
+  uv_subsize = ss_size_lookup[subsize][cm->subsampling_x][cm->subsampling_y];
+  if (subsize >= BLOCK_8X8 && uv_subsize == BLOCK_INVALID)
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Invalid block size.");
   if (subsize < BLOCK_8X8) {
     decode_block(cm, xd, tile, mi_row, mi_col, r, subsize);
   } else {