I'm the fool who didn't wash the snow off his bike - it's a rusty mess.

I've just taken apart the front disc brake as it was rubbing. I think that was more to do with the disc being bent, but as I was doing it, I found the disc brake pads (?) are pretty rusty. This is what they look like:

![Rusty disc brakes](https://i.stack.imgur.com/k507C.jpg)

Should this concern me at all? Can I clean them up, or should I replace them? Or are they fine just to be left?