115 lines
3.5 KiB
Nix
115 lines
3.5 KiB
Nix
# A profile with most (vanilla) hardening options enabled by default,
|
|
# potentially at the cost of features and performance.
|
|
|
|
{ config, lib, pkgs, ... }:
|
|
|
|
with lib;
|
|
|
|
{
|
|
meta = {
|
|
maintainers = [ maintainers.joachifm maintainers.emily ];
|
|
};
|
|
|
|
boot.kernelPackages = mkDefault pkgs.linuxPackages_hardened;
|
|
|
|
nix.allowedUsers = mkDefault [ "@users" ];
|
|
|
|
environment.memoryAllocator.provider = mkDefault "scudo";
|
|
environment.variables.SCUDO_OPTIONS = mkDefault "ZeroContents=1";
|
|
|
|
security.hideProcessInformation = mkDefault true;
|
|
|
|
security.lockKernelModules = mkDefault true;
|
|
|
|
security.protectKernelImage = mkDefault true;
|
|
|
|
security.allowSimultaneousMultithreading = mkDefault false;
|
|
|
|
security.forcePageTableIsolation = mkDefault true;
|
|
|
|
# This is required by podman to run containers in rootless mode.
|
|
security.unprivilegedUsernsClone = mkDefault config.virtualisation.containers.enable;
|
|
|
|
security.virtualisation.flushL1DataCache = mkDefault "always";
|
|
|
|
security.apparmor.enable = mkDefault true;
|
|
|
|
boot.kernelParams = [
|
|
# Slab/slub sanity checks, redzoning, and poisoning
|
|
"slub_debug=FZP"
|
|
|
|
# Overwrite free'd memory
|
|
"page_poison=1"
|
|
|
|
# Enable page allocator randomization
|
|
"page_alloc.shuffle=1"
|
|
];
|
|
|
|
boot.blacklistedKernelModules = [
|
|
# Obscure network protocols
|
|
"ax25"
|
|
"netrom"
|
|
"rose"
|
|
|
|
# Old or rare or insufficiently audited filesystems
|
|
"adfs"
|
|
"affs"
|
|
"bfs"
|
|
"befs"
|
|
"cramfs"
|
|
"efs"
|
|
"erofs"
|
|
"exofs"
|
|
"freevxfs"
|
|
"f2fs"
|
|
"hfs"
|
|
"hpfs"
|
|
"jfs"
|
|
"minix"
|
|
"nilfs2"
|
|
"ntfs"
|
|
"omfs"
|
|
"qnx4"
|
|
"qnx6"
|
|
"sysv"
|
|
"ufs"
|
|
];
|
|
|
|
# Restrict ptrace() usage to processes with a pre-defined relationship
|
|
# (e.g., parent/child)
|
|
boot.kernel.sysctl."kernel.yama.ptrace_scope" = mkOverride 500 1;
|
|
|
|
# Hide kptrs even for processes with CAP_SYSLOG
|
|
boot.kernel.sysctl."kernel.kptr_restrict" = mkOverride 500 2;
|
|
|
|
# Disable bpf() JIT (to eliminate spray attacks)
|
|
boot.kernel.sysctl."net.core.bpf_jit_enable" = mkDefault false;
|
|
|
|
# Disable ftrace debugging
|
|
boot.kernel.sysctl."kernel.ftrace_enabled" = mkDefault false;
|
|
|
|
# Enable strict reverse path filtering (that is, do not attempt to route
|
|
# packets that "obviously" do not belong to the iface's network; dropped
|
|
# packets are logged as martians).
|
|
boot.kernel.sysctl."net.ipv4.conf.all.log_martians" = mkDefault true;
|
|
boot.kernel.sysctl."net.ipv4.conf.all.rp_filter" = mkDefault "1";
|
|
boot.kernel.sysctl."net.ipv4.conf.default.log_martians" = mkDefault true;
|
|
boot.kernel.sysctl."net.ipv4.conf.default.rp_filter" = mkDefault "1";
|
|
|
|
# Ignore broadcast ICMP (mitigate SMURF)
|
|
boot.kernel.sysctl."net.ipv4.icmp_echo_ignore_broadcasts" = mkDefault true;
|
|
|
|
# Ignore incoming ICMP redirects (note: default is needed to ensure that the
|
|
# setting is applied to interfaces added after the sysctls are set)
|
|
boot.kernel.sysctl."net.ipv4.conf.all.accept_redirects" = mkDefault false;
|
|
boot.kernel.sysctl."net.ipv4.conf.all.secure_redirects" = mkDefault false;
|
|
boot.kernel.sysctl."net.ipv4.conf.default.accept_redirects" = mkDefault false;
|
|
boot.kernel.sysctl."net.ipv4.conf.default.secure_redirects" = mkDefault false;
|
|
boot.kernel.sysctl."net.ipv6.conf.all.accept_redirects" = mkDefault false;
|
|
boot.kernel.sysctl."net.ipv6.conf.default.accept_redirects" = mkDefault false;
|
|
|
|
# Ignore outgoing ICMP redirects (this is ipv4 only)
|
|
boot.kernel.sysctl."net.ipv4.conf.all.send_redirects" = mkDefault false;
|
|
boot.kernel.sysctl."net.ipv4.conf.default.send_redirects" = mkDefault false;
|
|
}
|