[belorn]

What qualify as a derivative is always a complicated issue. FSF and Linus Torvalds have both given their opinions about it, but it really is up to the court to decide if a kernel module relies on the kernel. They would ask if a kernel is module based on the functionality of the kernel, to the point where it expands on what the kernel do.

Words like based, expand, and relies on is keywords that the judge or jury would look at in identifying if something is a derivative work. A kernel module would likely have to pass each to not be declared as derivative.

The word "linking" or "loadable modules" however is not part of copyright, and would only come into question regarding the intent of the author. One could argue that thanks to linus posts, it shows that his intention is to allow such actions under non-gpl terms even if the module would be a derivative work under copyright law. That would however be limited to code that linus himself has written.