Merge pull request #48439 from joachifm/hardened-misc

nixos/security/misc: init

nixos/modules/profiles/hardened.nix

@@ -16,6 +16,8 @@ with lib;
 
   security.lockKernelModules = mkDefault true;
 
+  security.allowUserNamespaces = mkDefault false;
+
   security.apparmor.enable = mkDefault true;
 
   boot.kernelParams = [
@@ -59,18 +61,6 @@ with lib;
   # ... or at least apply some hardening to it
   boot.kernel.sysctl."net.core.bpf_jit_harden" = mkDefault true;
 
-  # A recurring problem with user namespaces is that there are
-  # still code paths where the kernel's permission checking logic
-  # fails to account for namespacing, instead permitting a
-  # namespaced process to act outside the namespace with the
-  # same privileges as it would have inside it.  This is particularly
-  # bad in the common case of running as root within the namespace.
-  #
-  # Setting the number of allowed user namespaces to 0 effectively disables
-  # the feature at runtime.  Attempting to create a user namespace
-  # with unshare will then fail with "no space left on device".
-  boot.kernel.sysctl."user.max_user_namespaces" = mkDefault 0;
-
   # Raise ASLR entropy for 64bit & 32bit, respectively.
   #
   # Note: mmap_rnd_compat_bits may not exist on 64bit.