From 8fa3b8d689a54d6d04ff7803c724fb7aca6ce98e Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 26 May 2016 15:42:13 -0400 Subject: [PATCH] cgroup: set css->id to -1 during init If percpu_ref initialization fails during css_create(), the free path can end up trying to free css->id of zero. As ID 0 is unused, it doesn't cause a critical breakage but it does trigger a warning message. Fix it by setting css->id to -1 from init_and_link_css(). Signed-off-by: Tejun Heo Cc: Wenwei Tao Fixes: 01e586598b22 ("cgroup: release css->id after css_free") Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Tejun Heo --- kernel/cgroup.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 789b84f973c9..688eb0cd1851 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -5063,6 +5063,7 @@ static void init_and_link_css(struct cgroup_subsys_state *css, memset(css, 0, sizeof(*css)); css->cgroup = cgrp; css->ss = ss; + css->id = -1; INIT_LIST_HEAD(&css->sibling); INIT_LIST_HEAD(&css->children); css->serial_nr = css_serial_nr_next++;