As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PASSENGERS IN 30AB REPORTED BURNING RUBBER SMELL. FLIGHT ATTENDANTS AND RELIEF PILOT CONFIRMED. SEARCHED AREA FOR POSSIBLE CAUSES NOTHING FOUND. AFTER APPROXIMATELY 10 MINUTES SMELL DISSIPATED. MAINTENANCE INSPECTED SEATS AND FOUND NO DAMAGES NOR SIGNS OF BURNS. REPLACED SEB AND SPM AS A PRECAUTIONARY.