jool: Unbreak with linux kernel >= 6.18 (#472559)

pkgs/os-specific/linux/jool/default.nix

@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  fetchpatch,
   kernel,
   kernelModuleMakeFlags,
   nixosTests,
@@ -16,6 +17,13 @@ stdenv.mkDerivation {
 
   src = sourceAttrs.src;
 
+  patches = lib.optionals (lib.versionAtLeast kernel.version "6.18.0") [
+    (fetchpatch {
+      url = "https://gitlab.alpinelinux.org/alpine/aports/-/raw/3.23-stable/community/jool-modules-lts/kernel-6.18.patch";
+      hash = "sha256-EtV95YaOzPU3e/8NQvUtAH/RWiV16djeKrnvSgYybCQ=";
+    })
+  ];
+
   nativeBuildInputs = kernel.moduleBuildDependencies;
   hardeningDisable = [ "pic" ];