postgresql: CREATE INDEX race condition possibly leading to privilege escalation

Race condition in the 1 CREATE INDEX and 2 unspecified ALTER TABLE commands in PostgreSQL before 8.4.20, 9.0.x before 9.0.16, 9.1.x before 9.1.12, 9.2.x before 9.2.7, and 9.3.x before 9.3.3 allows remote authenticated users to create an unauthorized index or read portions of unauthorized tables b...