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authorTycho Andersen <tycho@tycho.ws>2020-02-19 12:01:29 -0700
committerTejun Heo <tj@kernel.org>2020-03-04 11:53:33 -0500
commit2e5383d7904e60529136727e49629a82058a5607 (patch)
tree97142f1aa020ab593f1860a0f8521a243c98cdf6 /kernel/cgroup
parent190ecb190a9cd8c0599d8499b901e3c32e87966a (diff)
downloadlinux-2e5383d7904e60529136727e49629a82058a5607.tar.gz
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 64e90a8acb85 ("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>
Diffstat (limited to 'kernel/cgroup')
-rw-r--r--kernel/cgroup/cgroup-v1.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 9a6f060cbf51..f2d7cea86ffe 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -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);