Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Muchun Song <songmuchun@bytedance.com>,
        Roman Gushchin <guro@fb.com>, Michal Hocko <mhocko@suse.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Qian Cai <cai@lca.pw>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH 5.7 236/265] mm/memcontrol.c: add missed css_put()
Date:   Mon, 29 Jun 2020 11:17:49 -0400
Message-Id: <20200629151818.2493727-237-sashal@kernel.org>
In-Reply-To: <20200629151818.2493727-1-sashal@kernel.org>
References: <20200629151818.2493727-1-sashal@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Muchun Song <songmuchun@bytedance.com>

commit 3a98990ae2150277ed34d3b248c60e68bf2244b2 upstream.

We should put the css reference when memory allocation failed.

Link: http://lkml.kernel.org/r/20200614122653.98829-1-songmuchun@bytedance.com
Fixes: f0a3a24b532d ("mm: memcg/slab: rework non-root kmem_cache lifecycle management")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 mm/memcontrol.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1b05e25d8aef2..ef0e291a8cf46 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2790,8 +2790,10 @@ static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
 		return;
 
 	cw = kmalloc(sizeof(*cw), GFP_NOWAIT | __GFP_NOWARN);
-	if (!cw)
+	if (!cw) {
+		css_put(&memcg->css);
 		return;
+	}
 
 	cw->memcg = memcg;
 	cw->cachep = cachep;
-- 
2.25.1