Files
nix-config/hardening/apparmor/default.nix
T
Ryan Yin a7f7cb68f0 fix(apparmor): use inherit exec modifier in sudo complain profile
The broad 'file /** rwlkUx' rule conflicts with rix exec rules pulled in
via nested abstractions (xdg-open): AppArmor 5.0 rejects merged rules
with differing exec modifiers, failing apparmor.service on first load.
2026-08-30 12:57:09 +08:00

62 lines
2.2 KiB
Nix

{
config,
pkgs,
...
}:
{
# AppArmor: activate the LSM + load policies. Roll out in complain mode first
# (log violations, never block) so nothing can break; promote profiles to
# "enforce" individually once stable.
services.dbus.apparmor = "enabled";
security.apparmor = {
enable = true;
# Do not SIGTERM running unconfined-but-confinable processes yet.
# Safe to flip to true later now that no global default-deny profile is active.
killUnconfinedConfinables = false;
# Packages contributing to AppArmor's include path (abstractions).
# NOTE: these abstractions are FHS-oriented and reference FHS paths. nixpkgs does NOT
# provide a broad FHS->store alias layer (only /run/current-system, /usr/bin/env and
# /bin/sh are created), so some referenced paths do not resolve on NixOS and the
# resulting profiles are incomplete. They are safe only because they run in complain
# mode (log-only, no blocking); see hardening/README.md.
packages = [ pkgs.apparmor-profiles ];
policies = {
# Global default-deny scaffold. DANGEROUS to enable: `/**` matches every binary and
# the empty block allows nothing. Keep disabled until per-app profiles exist.
"default_deny" = {
state = "disable";
profile = "profile default_deny /** { }";
};
# Confine sudo; complain mode so a missing rule logs instead of blocking.
"sudo" = {
state = "complain";
profile = ''
abi <abi/4.0>,
include <tunables/global>
# NOTE: exec must use the `ix` (inherit) modifier here: abstractions/base
# pulls in nested rules like `rix` on specific binaries (via xdg-open etc.),
# and AppArmor 5.0's parser rejects merged rules with conflicting exec
# modifiers ("profile has merged rule with conflicting x modifiers") when a
# broad rule uses Ux over those paths.
profile ${pkgs.sudo}/bin/sudo {
include <abstractions/base>
file /** rwlkix,
}
'';
};
# nix runs unconfined (no restriction); inert, kept disabled.
"nix" = {
state = "disable";
profile = "profile ${config.nix.package}/bin/nix { unconfined, }";
};
};
};
}