Upvote:0
There are no issues with your travel plans. Your passport expires well after your planned arrival in Pakistan so you do not have to worry about transit or travel issues.
I recommend using the new online service which makes the renewal process automated and very simple to use; you can only use this if you are out of Pakistan though. The only reason I mention this is because it is quicker (1-2 weeks) vs. the normal month or more it takes in person.
If your old passport contains a valid visa, make sure you carry both passports with you upon your return to Australia.
Upvote:1
When going to the country that issued the passport it does not matter how little time is left (and sometimes not even whether it has already expired). Concern about remaining validity (often three or six months) is to make it easier to ship you out of the country you are visiting (eg Australia) but in this case Pakistan is your 'home' country, so that does not matter.