Why is the hose on my g e refrigerator ice maker freezing up causing water to go into my freezer?

It could have a rough edge on tip of hose causing water to collect on the end and freeze.

The water supply valve may not be shutting off completely allowing the water to drip.

Normal operation is the icemaker calls for water to refill. Since the water line is outside the fridge the water is warm. This warm water keeps that line from freezing. If the valve allows the water to drip then the water coming in is not warm because it moves so slow that the drip freezes as it enters the freezer.

It could be that you need a new water valve.