As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB, FLIGHT ATTENDANTS REPORTED SMOKE IN CABIN. FORWARD LAV DETECTOR SOUNDED. FLIGHT CREW RETURNED TO DEPARTURE AIRPORT. SMOKE BEGAN TO DISSIPATE DURING RETURN TO DEPARTURE AIRPORT. AN UNEVENTFUL LANDING WAS PERFORMED. MAINTENANCE FOUND APU OIL OVERSERVICED AND OIL IN THE PNEUMATIC DUCTS. PACK BURNOUT PROCEDURES WERE PERFORMED AND WATER SEPARATORS WERE REPLACED.