Luis Chamberlain sent out the modules changes today for the Linux 6.6 merge window. Most notable with the modules update is a change that better builds up the defenses against NVIDIA’s proprietary kernel driver from using GPL-only symbols. Or in other words, bits that only true open-source drivers should be utilizing and not proprietary kernel drivers like NVIDIA’s default Linux driver in respecting the original kernel code author’s intent.
Back in 2020 when the original defense was added, NVIDIA recommended avoiding the Linux 5.9 for the time being. They ended up having a supported driver several weeks later. It will be interesting to see this time how long Linux 6.6+ thwarts their kernel driver.
Open source software is given with specific licenses. The Linux kernel is made of many smaller open-source components that each can have their own license. Some of the licenses used disallow the partial or full usage of the licensed software or components in proprietary settings, or in general given usage for specific cases only (in this case, the Nvidia driver using components they are not licensed to use.).