Patch "cgroup: set css->id to -1 during init" has been added to the 4.6-stable tree

This is a note to let you know that I've just added the patch titled

    cgroup: set css->id to -1 during init

to the 4.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
cgroup-set-css-id-to-1-during-init.patch
and it can be found in the queue-4.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Tejun Heo <[email protected]>
Date: Thu, 26 May 2016 15:42:13 -0400
Subject: cgroup: set css->id to -1 during init

From: Tejun Heo <[email protected]>

commit 8fa3b8d689a54d6d04ff7803c724fb7aca6ce98e upstream.

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().

---
 kernel/cgroup.c |    1 +
 1 file changed, 1 insertion(+)

@@ -5063,6 +5063,7 @@ static void init_and_link_css(struct cgr
 	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++;

Patches currently in stable-queue which might be from [email protected] are

queue-4.6/memcg-css_alloc-should-return-an-err_ptr-value-on-error.patch queue-4.6/memcg-mem_cgroup_migrate-may-be-called-with-irq-disabled.patch queue-4.6/cgroup-disable-irqs-while-holding-css_set_lock.patch queue-4.6/cgroup-set-css-id-to-1-during-init.patch queue-4.6/cgroup-remove-redundant-cleanup-in-css_create.patch queue-4.6/mm-memcontrol-fix-cgroup-creation-failure-after-many-small-jobs.patch