1 files changed, 36 insertions, 0 deletions
diff --git a/nixos/modules/security/lock-kernel-modules.nix b/nixos/modules/security/lock-kernel-modules.nix
new file mode 100644
index 00000000000..51994ee76c1
--- /dev/null
+++ b/nixos/modules/security/lock-kernel-modules.nix
@@ -0,0 +1,36 @@
+{ config, lib, ... }:
+
+with lib;
+
+{
+  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 {
+    systemd.services.disable-kernel-module-loading = rec {
+      description = "Disable kernel module loading";
+
+      wantedBy = [ config.systemd.defaultUnit ];
+      after = [ "systemd-udev-settle.service" "firewall.service" "systemd-modules-load.service" ] ++ wantedBy;
+
+      script = "echo -n 1 > /proc/sys/kernel/modules_disabled";
+
+      unitConfig.ConditionPathIsWritable = "/proc/sys/kernel";
+
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+      };
+    };
+  };
+}