They can forbid you to work on opensource stuff while being in free time? I mean, I understand that you are not allowed to generate open code that utilises private know how of the company you work for. But not working on Linux in free time seems very strange to me 😮
Edit: deleted wrong “Edit:”
Thats just dual booting. That wont work with the law if the contract says anything created using company hardware is theirs.
And yes, some companies need to give you a green light to work on projects in your free time, because they might have a team doing similar things somewhere, it might compete in something they would like to do in the future or like you said, might use company know how which is a huge nono.
Its bs imo, but those clauses and rules are found in some employment agreements.
Remember, always read your employment agreements!