As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDIS 609 36-10 1516 22DEC21 ICN OPEN U CLIMBING THROUGH 3500 COCKPIT FILLED WITH LIGHT GRAY SMOKE. DECLARED EMERGENCY, RAN APPROPRIATE CHECKLISTS, RETURNED TO INCHEON. DID NOT DUMP FUEL. NO OTHER ISSUES NOTED ENG 1 WAS CAUSE OF SMOKE. FACT 27DEC21 09:50 MEM #1 ENGINE CHANGED REF MD-11 WIC 71T0901-GE.