I'm on a UA award HNL-AKL-WLG-SYD-BKK-SIN-PVG-NRT-HNL. I have a 3 hour and 40 minute layover in PVG. Since I'm not leaving the airport I'm assuming I don't need a transit visa.

However, if my connecting flight to NRT gets cancelled for whatever reason and I need to overnight in Shanghai, I should be OK for 72 hours without a visa right?