Living in US on L2Visa / Australian Passport -heading to New Zealand transiting in Shanghai

Hello

Could you please advise, Living in the US on an Australian passport with an L2 entry permit, Heading to a wedding in New Zealand in January going New York-Shanghai -Auckland. The transit in Shanghai is 4 hours. Do we need a entry permit? Or if there was some sort of delay - would we require a visa ? Thank you.