As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF AT 25,000FT AFT LAV SMOKE MASTER WARNING ILLUMINATED. FLIGHT ATTENDENT INVESTIGATION REVEALED NO SMOKE OR FIRE BUT ABNORMAL ODOR WAS DETECTED. FLIGHT CREW ELECTED TO RETURN TO DEPARTURE AIRPORT. MAINTENANCE FOUND THE APU INLET SOAKED WITH OIL AND OIL LEAK AT APU OIL COOLER. APU PLACED ON MEL.