As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE IN CABIN DURING CLIMB AT FL 50, SMOKE STARTED ENTERING THE CABIN. THE CREW ELECTED TO RETURN TO THE POINT OF DEPARTURE WHERE AN UNEVENTFUL LANDING WAS MADE. POST FLIGHT INSP FOUND OIL ON THE FAN AND THE CABIN BLEED PORT. TROUBLESHOOTING IS ON-GOING.