From 4b9502e63b5e2b1b5ef491919d3219b9440fe0b3 Mon Sep 17 00:00:00 2001
From: Elena Reshetova <elena.reshetova@intel.com>
Date: Wed, 8 Mar 2017 10:00:40 +0200
Subject: kernel: convert css_set.refcount from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
 include/linux/cgroup-defs.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'include/linux/cgroup-defs.h')

diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 6a3f850cabab..c74b78ecd583 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -13,6 +13,7 @@
 #include <linux/wait.h>
 #include <linux/mutex.h>
 #include <linux/rcupdate.h>
+#include <linux/refcount.h>
 #include <linux/percpu-refcount.h>
 #include <linux/percpu-rwsem.h>
 #include <linux/workqueue.h>
@@ -156,7 +157,7 @@ struct css_set {
 	struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
 
 	/* reference count */
-	atomic_t refcount;
+	refcount_t refcount;
 
 	/* the default cgroup associated with this css_set */
 	struct cgroup *dfl_cgrp;
-- 
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