Visa exemption?

We are Canadian and US travellers living in Canada flying from Siem Reap into the PRC via Guangzhou...we have a connecting flight to Beijing Capital Airport from where we will fly into the US. This all occurs from May 17th arrival at 2315 into Guangzhou to departure on May 18th at 1600 hours from Bejing. Are we required to have an entry permit...we have confirmed booked flights with seats and a reservation confirmed at the Pullman Baiyun hotel in Guangzhou since we arrive at 2315 and our connecting flight is in the morning to Beijing at 1200 noon and departing from Beijing for US at 1600 hours.
Do we need an entry permit?