Can I freeze soup in a pot?
There are no health safety risks with storing food in a stainless steel, or most other cooking pot metals for that mater

The pot should be fine, but there is always a risk with metal in a freezer in that bare skin contact may freeze to it. Also other products in freezer bags may even freeze to it

In general it's easier not to use metal containers in the freezer, unless enamelled or plastic coated