As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB THE CREW REPORTED SMOKE IN THE CABIN. CREW DID NOT DECLARE EMERGENCY FLIGHT LANDED WITHOUT INCIDENT. PASSENGERS DEPLANED THROUGH NORMAL DOOR. MAINTENANCE PERSONNEL CLEANED AND RECONECTED THE LAV SMOKE DETECTOR CANNON PLUG. IT WAS DETERMINED SMOKE WAS CAUSED BY RESIDUAL OIL FROM PREVIOUS APU OIL LEAK. A SATISFACTORY OPERATIONAL CHECK WAS PERFORMED AND AIRCRAFT WAS RELEASED FOR CONTINUED SERVICE.