The excellent Star Alliance Passport & Visa link is just a guideline and specifically does not address the OPs issue regarding passport validity.

Unfortunately the "six month rule" whereby some countries seem to require that a passport be valid for six months (or less) beyond the anticipated departure date is unwritten (as best as I can find) in the *A link.

There are enough references in FT to the requirement for passports to have a six month validity when entering or even transiting some countries for the OP to be concerned. The logical thing for everyone in the OPs situation to do is check with the embassy/consulate/high commission of the country(ies) in question.

Unfortunately there is no "golden bible" reference source for this info.