As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RDM- ON FLIGHT 2055 AT 20,000 FEET, DURING DESCENT UNKNOWN SOURCE OF SMOKE FILLED CABIN AND COCKPIT TO A "HAZE" LEVEL WITH ASSOCIATED BURINING SMELL OF POSSIBLY OIL. THIS DECREASED AS THE FLIGHT CONTINUED. INSPECTED BOTH ENGINE OIL LEVELS. GROUND RAN EACH ENGINE. NO PARTS REPLACED. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.