A Lufthansa Boeing 747-400, registration D-ABVU performing flight LH-732 from Frankfurt/Main (Germany) to Shanghai Pudong (China) with 370 people on board, was climbing out of Frankfurt's runway 25C when the crew stopped the climb at FL080 reporting they had a #3 engine (CF6, right inboard) stall. The crew subsequently reported they needed to dump fuel and return to Frankfurt. The aircraft climbed to FL180, dumped fuel and returned to Frankfurt for a safe landing on runway 25C about 90 minutes after departure.