From d2e61b8dc99fdb36e0fd176e25365f69afda4ff9 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <error27@gmail.com>
Date: Thu, 11 Nov 2010 14:05:12 -0800
Subject: memcg: null dereference on allocation failure

The original code had a null dereference if alloc_percpu() failed.  This
was introduced in commit 711d3d2c9bc3 ("memcg: cpu hotplug aware percpu
count updates")

Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/memcontrol.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9a99cfaf0a19..2efa8ea07ff7 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4208,15 +4208,17 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
 
 	memset(mem, 0, size);
 	mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
-	if (!mem->stat) {
-		if (size < PAGE_SIZE)
-			kfree(mem);
-		else
-			vfree(mem);
-		mem = NULL;
-	}
+	if (!mem->stat)
+		goto out_free;
 	spin_lock_init(&mem->pcp_counter_lock);
 	return mem;
+
+out_free:
+	if (size < PAGE_SIZE)
+		kfree(mem);
+	else
+		vfree(mem);
+	return NULL;
 }
 
 /*
-- 
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