5cb2cee954
Conditioning `sysctl.kptr_restrict` on `features.grsecurity` supports any grsecurity enabled kernel without having to enable the grsecurity module.
70 lines
2.1 KiB
Nix
70 lines
2.1 KiB
Nix
{ config, lib, pkgs, ... }:
|
|
|
|
with lib;
|
|
|
|
let
|
|
|
|
sysctlOption = mkOptionType {
|
|
name = "sysctl option value";
|
|
check = val:
|
|
let
|
|
checkType = x: isBool x || isString x || isInt x || isNull x;
|
|
in
|
|
checkType val || (val._type or "" == "override" && checkType val.content);
|
|
merge = loc: defs: mergeOneOption loc (filterOverrides defs);
|
|
};
|
|
|
|
in
|
|
|
|
{
|
|
|
|
options = {
|
|
|
|
boot.kernel.sysctl = mkOption {
|
|
default = {};
|
|
example = {
|
|
"net.ipv4.tcp_syncookies" = false;
|
|
"vm.swappiness" = 60;
|
|
};
|
|
type = types.attrsOf sysctlOption;
|
|
description = ''
|
|
Runtime parameters of the Linux kernel, as set by
|
|
<citerefentry><refentrytitle>sysctl</refentrytitle>
|
|
<manvolnum>8</manvolnum></citerefentry>. Note that sysctl
|
|
parameters names must be enclosed in quotes
|
|
(e.g. <literal>"vm.swappiness"</literal> instead of
|
|
<literal>vm.swappiness</literal>). The value of each
|
|
parameter may be a string, integer, boolean, or null
|
|
(signifying the option will not appear at all).
|
|
'';
|
|
};
|
|
|
|
};
|
|
|
|
config = {
|
|
|
|
environment.etc."sysctl.d/nixos.conf".text =
|
|
concatStrings (mapAttrsToList (n: v:
|
|
optionalString (v != null) "${n}=${if v == false then "0" else toString v}\n"
|
|
) config.boot.kernel.sysctl);
|
|
|
|
systemd.services.systemd-sysctl =
|
|
{ wantedBy = [ "multi-user.target" ];
|
|
restartTriggers = [ config.environment.etc."sysctl.d/nixos.conf".source ];
|
|
};
|
|
|
|
# Enable hardlink and symlink restrictions. See
|
|
# https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=800179c9b8a1e796e441674776d11cd4c05d61d7
|
|
# for details.
|
|
boot.kernel.sysctl."fs.protected_hardlinks" = true;
|
|
boot.kernel.sysctl."fs.protected_symlinks" = true;
|
|
|
|
# Hide kernel pointers (e.g. in /proc/modules) for unprivileged
|
|
# users as these make it easier to exploit kernel vulnerabilities.
|
|
#
|
|
# Removed under grsecurity.
|
|
boot.kernel.sysctl."kernel.kptr_restrict" =
|
|
if (config.boot.kernelPackages.kernel.features.grsecurity or false) then null else 1;
|
|
};
|
|
}
|