Temozolomide With or Without Veliparib in Treating Patients With Newly Diagnosed Glioblastoma Multiforme

Inclusion Criteria: * Histologic documentation: newly diagnosed World Health Organization (WHO) grade IV intracranial glioblastoma or gliosarcoma; GBM with oligodendroglial features are NOT PERMITTED in this study if they are 1p19q codeleted; sites submitting GBM with oligodendroglial features will be asked to provide results of 1p/19q codeletion status * Sufficient tissue available for central pathology review and MGMT methylation status evaluation * Patients who have had a local MGMT testing that is unmethylated are not allowed to participate * Tumor MGMT promoter hypermethylation determined by central testing at MD Anderson * Confirmation by central pathology review of WHO grade IV glioblastoma or gliosarcoma * Absolute neutrophil count (ANC) \>= 1500 cells/mm\^3 (within 14 days prior to study registration) * Platelets \>= 100,000 cells/mm\^3 (within 14 days prior to study registration) * Creatinine =\< 1.5 x upper limit of normal (ULN) (within 14 days prior to study registration) * Bilirubin =\< 1.5 x ULN (within 14 days prior to study registration; unless patient has Gilbert's disease) * Alanine aminotransferase (ALT) =\< 3 x ULN (within 14 days prior to study registration) * Aspartate aminotransferase (AST) =\< 3 x ULN (within 14 days prior to study registration) * Eastern Cooperative Oncology Group (ECOG) performance status =\< 2 * Measurable disease or non-measurable disease; extent of resection: patients with complete resection, partial resection, or biopsy are elig…