Free Entry Visa?

Hi - I am holding a Canadian Passport and will be arriving at the ShangHai Cruise Port from a Cruise Ship at 3am and then immediately will take a taxi to the PuDong Airport to go from ShangHai back to Canada. I am wondering if we need a Chinese Visa for this temporary transit situation? I have found on some internet sites that we don't need a visa but I am not sure how reliable it is... Please advise. Thank you for your help!