kdePackages.kwin: apply lowering CAP_SYS_NICE patch

From 232e480ab1303f37d37d295b57fdcbb6b6648bca Mon Sep 17 00:00:00 2001

From: Alois Wohlschlager <alois1@gmx-topmail.de>

Date: Sun, 7 Aug 2022 16:12:31 +0200

Subject: [PATCH] Lower CAP_SYS_NICE from the ambient set

The capabilities wrapper raises CAP_SYS_NICE into the ambient set so it

is inherited by the wrapped program. However, we don't want it to leak

into the entire desktop environment.

Lower the capability again at startup so that the kernel will clear it

on exec.

---

 src/main_wayland.cpp | 3 +++

 1 file changed, 3 insertions(+)

diff --git a/src/main_wayland.cpp b/src/main_wayland.cpp

index 1720e14e7..f2bb446b0 100644

--- a/src/main_wayland.cpp

+++ b/src/main_wayland.cpp

@@ -39,7 +39,9 @@

 #include <QWindow>

 #include <qplatformdefs.h>

+#include <linux/capability.h>

 #include <sched.h>

+#include <sys/prctl.h>

 #include <sys/resource.h>

 #include <iomanip>

@@ -285,6 +287,7 @@ static QString automaticBackendSelection()

 int main(int argc, char *argv[])

 {

+    prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_LOWER, CAP_SYS_NICE, 0, 0);

     KWin::Application::setupMalloc();

     KWin::Application::setupLocalizedString();

     KWin::gainRealTime();

-- 

2.37.1

    # The rest are NixOS-specific hacks

    ./0003-plugins-qpa-allow-using-nixos-wrapper.patch

    ./0001-NixOS-Unwrap-executable-name-for-.desktop-search.patch

    ./0001-Lower-CAP_SYS_NICE-from-the-ambient-set.patch

  ];

  postPatch = ''