From c0834113766a190fd3a042790e824c85709fc7f1 Mon Sep 17 00:00:00 2001
From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Tue, 30 Jul 2024 11:53:32 +0200
Subject: [PATCH 0812/1160] cgroup-util: Ignore kernel threads in
 cg_kill_items()

Similar to the implementation of cgroup.kill in the kernel, let's
skip kernel threads in cg_kill_items() as trying to kill kernel
threads as an unprivileged process will fail with EPERM and doesn't
do anything when running privileged.

(cherry picked from commit 0fbb569de1dcc06118dba006cf7a40caf6cd94d0)
(cherry picked from commit 3d90344e941f10b6fe7b1a315b79ca09c4451a86)
---
 src/basic/cgroup-util.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index 3b58db779e..a3648ee376 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -348,6 +348,12 @@ static int cg_kill_items(
                         if (set_get(s, PID_TO_PTR(pidref.pid)) == PID_TO_PTR(pidref.pid))
                                 continue;
 
+                        /* Ignore kernel threads to mimick the behavior of cgroup.kill. */
+                        if (pidref_is_kernel_thread(&pidref) > 0) {
+                                log_debug("Ignoring kernel thread with pid " PID_FMT " in cgroup '%s'", pidref.pid, path);
+                                continue;
+                        }
+
                         if (log_kill)
                                 ret_log_kill = log_kill(&pidref, sig, userdata);
 
-- 
2.33.0