Commit 2e5383d7 authored Feb 19, 2020 by Tycho Andersen Committed by Tejun Heo Mar 04, 2020

cgroup1: don't call release_agent when it is ""



Older (and maybe current) versions of systemd set release_agent to "" when
shutting down, but do not set notify_on_release to 0.

Since 64e90a8a ("Introduce STATIC_USERMODEHELPER to mediate
call_usermodehelper()"), we filter out such calls when the user mode helper
path is "". However, when used in conjunction with an actual (i.e. non "")
STATIC_USERMODEHELPER, the path is never "", so the real usermode helper
will be called with argv[0] == "".

Let's avoid this by not invoking the release_agent when it is "".

Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: Tejun Heo <tj@kernel.org>

parent 190ecb19

kernel/cgroup/cgroup-v1.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -783,7 +783,7 @@ void cgroup1_release_agent(struct work_struct *work)

		pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
		agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);
		if (!pathbuf \|\| !agentbuf)
		if (!pathbuf \|\| !agentbuf \|\| !strlen(agentbuf))
		goto out;

		spin_lock_irq(&css_set_lock);

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