So, first off. There is no reason for GPS jamming to cause a crash. Modern airliners have other ways to navigate.
Now it is possible to target a single aircraft with GPS "spoofing" potentially, but both GPS and Galileo have ways round this (Navigation Message Authentication). I would like to think aircraft navigation systems should be using this system. But, even if not, I'd bet it's still quite hard to reliably spoof a specific location to a moving aircraft.