ANSWER:
Cartoon movies that are educational and don’t teach things against Islam are permissible to watch.
As for Cinderella, I remember that it has a love story between Cinderella and the prince and there is a dance and mixing between the genders which goes against Islamic teachings that we try to teach our children.
I don’t know about Kung Fu Panda and I don’t know about Shirk, though I think it also has a love story between an ogre and a princess.
Therefore, it is best not to bring up our children on watching movies that goes against what Islam teaches.