Strange fungus-like growth on tree
I have two trees in my back garden. I have no idea what type they are as we have only lived here since November and they haven't had leaves on them yet.
A large branch has broken off one of them. Inside the branch, the wood has a whiteish look:
On the outside of the tree, there are also fungus-like things growing on its bark:
These are hard and wood-like to touch.
Is this growth killing the tree? If so, can I stop it somehow?