Password & SSH Key issues are only applicable to the developer users of kernel.org and the associated servers...so that's not you unless you have been keeping quiet about it

The remaining issues are:
1) Was kernel.org web script\pages spiked to put malware on your client via your web browser.
2) Was the git repository tampered with, introducing malware source\data.
1 I am sure (from your posts) you know how to check for this (quicker to do than explain every step how)
EDIT: And I am sure kernel.org would have announced it if they found tampering with the webserver.
2 Is unlikely, you can point git at github and pull Linus's tree from there instead (anything amiss in your repository will cause errors)
EDIT:
3) They stole the SSL Certificates, polluted the DNS servers, and redirected you to a clone of kernel.org to have thier wicked way with your trusting clent