@ml I hate to break it to you, but the kernel Linux is neither free software, nor "open source" - it's proprietary software.

It contains many proprietary programs, disguised as arrays of numbers, without source code.

Of course you're now allowed to contribute to proprietary software if you were born in the wrong country.

If you want a free version of Linux, you need GNU Linux-libre; https://www.fsfla.org/ikiwiki/selibre/linux-libre/