do i still need 6 month validity on my passport if I am directly transiting through Guangzhou

Hello,
I will be traveling to Australia from the UK on october 28th 2016 and returning to the UK from Australia on November 13th 2016.

My flights stop in Guangzhou on the way to Australia and on the return journey too.
I am aware that I can enter China free under a 72 hour visa waiver, or even for 24 hours direct transit, however I am unsure as to whether my passport still needs to have 6 months validity if I do not intend to leave the airport whilst in Guangzhou?

My passport expires 26/April/2017.
My flights stop in Guangzhou on 29/october/2016 for 4-hours and 5-mins, then on the return my flight stops in Guangzhou on 13/November/2016 for 6-hours and 25-mins.

Do I need to get a new passport for my journey to Australia?
Thanks for your help. Rachel Fox