Commit 8fa3b8d6 authored May 26, 2016 by Tejun Heo

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 <tj@kernel.org>
Cc: Wenwei Tao <ww.tao0320@gmail.com>
Fixes: 01e58659 ("cgroup: release css->id after css_free")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Tejun Heo <tj@kernel.org>

parent b00c52da

kernel/cgroup.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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++;

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