From 8739f8cd7b2ca4cd87ffb4fa924a390db281c39c Mon Sep 17 00:00:00 2001
From: Martin Weinelt <hexa@darmstadt.ccc.de>
Date: Sun, 20 Jun 2021 13:52:03 +0200
Subject: [PATCH] nixos/babeld: update hardening

---
 nixos/modules/services/networking/babeld.nix | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/services/networking/babeld.nix b/nixos/modules/services/networking/babeld.nix
index 5e14283179ac..aae6f1498a42 100644
--- a/nixos/modules/services/networking/babeld.nix
+++ b/nixos/modules/services/networking/babeld.nix
@@ -104,6 +104,7 @@ in
         ExecStart = "${pkgs.babeld}/bin/babeld -c ${configFile} -I /run/babeld/babeld.pid -S /var/lib/babeld/state";
         AmbientCapabilities = [ "CAP_NET_ADMIN" ];
         CapabilityBoundingSet = [ "CAP_NET_ADMIN" ];
+        DevicePolicy = "closed";
         DynamicUser = true;
         IPAddressAllow = [ "fe80::/64" "ff00::/8" "::1/128" "127.0.0.0/8" ];
         IPAddressDeny = "any";
@@ -123,12 +124,17 @@ in
         RemoveIPC = true;
         ProtectHome = true;
         ProtectHostname = true;
+        ProtectProc = "invisible";
         PrivateMounts = true;
         PrivateTmp = true;
         PrivateDevices = true;
         PrivateUsers = false; # kernel_route(ADD): Operation not permitted
+        ProcSubset = "pid";
         SystemCallArchitectures = "native";
-        SystemCallFilter = [ "@system-service" ];
+        SystemCallFilter = [
+          "@system-service"
+          "~@privileged @resources"
+        ];
         UMask = "0177";
         RuntimeDirectory = "babeld";
         StateDirectory = "babeld";