From: Vasiliy Kulikov <redacted>
Date: Sun, 27 Feb 2011 14:44:38 +0300

Then the things are still broken - a user has to update modprobe
together with the kernel, otherwise the updated kernel would call
"modprobe" with unsupported argument and even "sit0" wouldn't work.

The capability bits get passed on the modprobe command line.

The module loading system call in the kernel inspects the command
line looking for the argument, and uses it to validate the module
load by comparing the mask with the special ELF section.