As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AIRCRAFT NOT GROUNDED) FLIGHT ATTENDANTS AND PAX REPORTED DIRTY SOCK SMELL AS WE STARTED TO DESCEND / DURING T/C 21-000-002 AFTER CLEANING APU & RUNNING FOUND OIL ON APU AIR INLET PLENUM FLANG AND INLET SCREEN. PERFORMED TASK CARD 21-000-003 FOUND APU TO BE CLEAN AND NO SMELL OPS CHECK GOOD AT THIS TIME.