nixpkgs/nixos/modules/security/lock-kernel-modules.nix
rnhmjoj 1bd7260adb
nixos/lock-kernel-modules: reorder before/after
Moving the service before multi-user.target (so the `hardened` test
continue to work the way it did before) can result in locking the kernel
too early. It's better to lock it a bit later and changing the test to
wait specifically for the disable-kernel-module-loading.service.
2021-09-19 12:06:00 +02:00

59 lines
1.5 KiB
Nix

{ config, pkgs, lib, ... }:
with lib;
{
meta = {
maintainers = [ maintainers.joachifm ];
};
options = {
security.lockKernelModules = mkOption {
type = types.bool;
default = false;
description = ''
Disable kernel module loading once the system is fully initialised.
Module loading is disabled until the next reboot. Problems caused
by delayed module loading can be fixed by adding the module(s) in
question to <option>boot.kernelModules</option>.
'';
};
};
config = mkIf config.security.lockKernelModules {
boot.kernelModules = concatMap (x:
if x.device != null
then
if x.fsType == "vfat"
then [ "vfat" "nls-cp437" "nls-iso8859-1" ]
else [ x.fsType ]
else []) config.system.build.fileSystems;
systemd.services.disable-kernel-module-loading = {
description = "Disable kernel module loading";
wants = [ "systemd-udevd.service" ];
wantedBy = [ config.systemd.defaultUnit ];
after =
[ "firewall.service"
"systemd-modules-load.service"
config.systemd.defaultUnit
];
unitConfig.ConditionPathIsReadWrite = "/proc/sys/kernel";
serviceConfig =
{ Type = "oneshot";
RemainAfterExit = true;
TimeoutSec = 180;
};
script = ''
${pkgs.udev}/bin/udevadm settle
echo -n 1 >/proc/sys/kernel/modules_disabled
'';
};
};
}