Adds an option `security.lockKernelModules` that, when enabled, disables
kernel module loading once the system reaches its normal operating state.
The rationale for this over simply setting the sysctl knob is to allow
some legitmate kernel module loading to occur; the naive solution breaks
too much to be useful.
The benefit to the user is to help ensure the integrity of the kernel
runtime: only code loaded as part of normal system initialization will be
available in the kernel for the duration of the boot session. This helps
prevent injection of malicious code or unexpected loading of legitimate
but normally unused modules that have exploitable bugs (e.g., DCCP use
after free CVE-2017-6074, n_hldc CVE-2017-2636, XFRM framework
CVE-2017-7184, L2TPv3 CVE-2016-10200).
From an aestethic point of view, enabling this option helps make the
configuration more "declarative".
Closes https://github.com/NixOS/nixpkgs/pull/24681
Upstream has decided to make -testing patches private, effectively ceasing
free support for grsecurity/PaX [1]. Consequently, we can no longer
responsibly support grsecurity on NixOS.
This patch turns the kernel and patch expressions into build errors and
adds a warning to the manual, but retains most of the infrastructure, in
an effort to make the transition smoother. For 17.09 all of it should
probably be pruned.
[1]: https://grsecurity.net/passing_the_baton.php
This reduces the time window during which IP addresses are gone during
switch-to-configuration. A complication is that with stopIfChanged =
true, preStop would try to delete the *new* IP addresses rather than
the old one (since the preStop script now runs after the switch to the
new configuration). So we now record the actually configured addresses
in /run/nixos/network/addresses/<interface>. This is more robust in
any case.
Issue https://github.com/NixOS/nixops/issues/640.
Commit 75f131da02 added
`chown 'nginx:nginx' '/var/lib/acme'` to the pre-start script,
but since it doesn't use `chown -R`, it is possible that there
are older existing subdirs (like `acme-challenge`)
that are owned to `root` from before that commit went it.
* The source attribute is mandatory, not optional
* The program attribute is optional
* Move the info about the mandatory attribute first (most important,
IMHO)
