Brownfields Reauthorization Act of 2017 (Sec. 2) This bill modifies the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) to specify if a state or local government takes title to a brownfield site as a result of law enforcement activity, that government is not an owner or operator for the purposes of CERCLA. (Brownfields are certain commercial properties that are hindered from reuse or redevelopment due to the presence of a hazardous substance, pollutant, or contaminant.) (Sec. 3) The bill modifies brownfield program eligibility with respect to petroleum sites where no viable responsible party exists. Specifically, it eliminates the requirement that sites be of relatively low risk. (Sec. 4) The bill revises leaseholder status regarding bona fide prospective purchasers. (Sec. 5) The bill expands CERCLA eligibility for nonprofit organizations and qualified community development entities. (Sec. 6) The brownfield site characterization and assessment grant program and the brownfield remediation grant and loan program are revised by authorizing eligible governmental entities to receive grants and loans for property that was acquired before January 11, 2002, even if the entities do not qualify as bona fide prospective purchasers. (Sec. 7) The bill increases the cap on the amount that may be given in grants and loans for each site to be remediated. (Sec. 8) The Environmental Protection Agency (EPA) must establish a program to provide multipurpose grants to carry out inventory, characterization, assessment, planning, or remediation activities at brownfield sites. (Sec. 9) The bill allows grant recipients to use up to 5% of funds for administrative costs. (Sec. 10) The bill reauthorizes brownfields revitalization funding through FY2022. (Sec. 11) The bill reauthorizes state response programs through FY2022.