"The Linux kernel" makes sense. Real language, particularly names, do not have to follow strict grammatical rules.
Although, now that I think about it, there probably is a name for this sort of thing, because we do it often, particularly with brands. Marlboro cigarettes. Pepsi soda.
Brand names are sometimes called "proper adjectives". I seem to remember reading that food brands in particular must modify a noun that describes the food.
Although, now that I think about it, there probably is a name for this sort of thing, because we do it often, particularly with brands. Marlboro cigarettes. Pepsi soda.