SELinux is a security enhancement to Linux which provides users and administrators a more granular, powerful access control mechanism. It consists of a kernel component which enforces the security policy, a set of userspace tools to manage and manipulate SELinux security policies, and the SELinux security policies themselves.
The main Linux Kernel README can be found at Documentation/admin-guide/README.rst
The canonical SELinux kernel repository is hosted by kernel.org:
There is also an officially maintained GitHub mirror:
After the merge window closes upstream, a decision will be made regarding the need to rebase the next branch on top of the current Linux -rc1 release. If there have been a number of subsystem related changes outside of the subsystem‘s next branch, or if the branch’s base is too far behind linux/master, it may be necessary to rebase the next branch. If a rebase is needed, it should be done before any patches are merged, and rebasing the next branch during the remaining -rcX releases should only be done in extreme cases.
Patches will be merged into the subsystem's next branch during the development cycle which extends from merge window close up until the merge window reopens. However, it is important to note that large, complicated, or invasive patches sent late in the development cycle may be deferred until the next cycle. As a general rule, only small patches or critical fixes will be merged after -rc5/-rc6.
Any patches deemed necessary for the current Linux -rcX releases will be merged into the current stable-X.Y branch, marked with a signed tag, and a pull request sent against linux/master as soon as it is reasonable to do so.
During the development cycle Fedora Rawhide test kernels will be generated using the next and most recent stable-X.Y branches on a weekly basis, if not more often. These kernels will be tested against the SELinux test suite and audit test suite as well as being made available to everyone for additional testing.
Once the merge window opens, the next branch will be copied to a new branch, stable-X.Y, and the branch will be marked with a signed tag in the format selinux-pr-YYYYMMDD. A pull request will be sent against the linux/master branch using the signed tag.
The SELinux reference policy, userspace tools, and test suites are hosted by GitHub: