+ ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
+ if (ef->zero_cluster == NULL)
+ {
+ exfat_close(ef->dev);
+ free(ef->sb);
+ exfat_error("failed to allocate zero sector");
+ return -ENOMEM;
+ }
+ /* use zero_cluster as a temporary buffer for VBR checksum verification */
+ if (!verify_vbr_checksum(ef->dev, ef->zero_cluster, SECTOR_SIZE(*ef->sb)))
+ {
+ free(ef->zero_cluster);
+ exfat_close(ef->dev);
+ free(ef->sb);
+ return -EIO;
+ }
+ memset(ef->zero_cluster, 0, CLUSTER_SIZE(*ef->sb));