I'm traveling from JED Saudi Arabia to Singapore by Saudi airlines. My last name doesn't match the passport. But all other details are same, e.g. passport no., DOB, etc.
AFAIK, to book for international flights you have to match the name in the booking with the name in the passport. How did you manage to get a different name? Anyway, the airline check-in agent will check the passport before printing the boarding pass. If the name does not match the agent might refuse you. There is a strict rules regarding this. Also, the passport control officers in Saudi Arabia will check the name in the boarding pass and make sure it matches the one in the passport.
Anyway, if the difference is just some letters then there will be no problem (or if the name is reversed). One thing to mention here, Arabs use three parts name or four parts name
first, middle, [middle 2], last, if the name shown in the ticket is
last+middle then most likely it will be ok.
If the name is totally different than the one in passport then that is a problem, just visit any ticketing office to fix it.