I turned my child safety lock on and now both back doors won't open from the inside or outside on my 2008 malibu

SOURCE: outside door handle broke and child lock on

get a locksmith he or she should be able to open the door through the window.

SOURCE: Passenger Door won't open from inside - not child safety lock

as leegallacher said its more than likely the interior door cable stretched or ends worn.

Testimonial: "That was the problem."

SOURCE: my back doors do not

It is probably due to bent rods that attach to the handle and run to the latching mechanism inside the door panel. If you remove the door panel with the window up you should be able to reach in and straighten the rods.This was a recurring problem on mine.

SOURCE: 1997 Geo Metro rear door won't open!

I have the same car, same problem. I've still not been able to fix it, despite taking the inside panels off the rear doors, checking the rods were seated, applying WD-40 to the lock mechanisms, and manually working the mechanism. Child locks are not engaged, but I tried putting them on and off too. Just won't open.

SOURCE: Driver's door won't open inside

Hey, You need to remove the panel otherwise u can't reattach the metal sticks that move the locks, but i think it's hard to remove it in a closed posision when u don't brake it