Banana bread question: How long can you keep frozen bananas?

I was always told that when you have over-ripe bananas, you can just toss them in the freezer and use them for banana bread.

Today I had the urge to make banana bread and pulled the bananas out of the freezer to thaw. One they were defrosted, I unpeeled them and put them in a bowl where they lay like little brown slimy slugs.

Are they supposed to smell fermented and be that colour? I’m guessing age may have something to do with it, two of them were lighter then the rest and don’t smell so strong. No idea how long I’ve had them in there.

Should I still use them? Will I kill my friends at the potluck this weekend with toxic banana bread? Or will it be the best kick-ass banana bread in town?