From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: [PATCH] memcg: avoid accessing memcg after releasing reference Date: Mon, 1 Apr 2013 10:39:00 +0800 Message-ID: <5158F344.9020509@huawei.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Glauber Costa Cc: Michal Hocko , KAMEZAWA Hiroyuki , Johannes Weiner , LKML , Cgroups , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Andrew Morton This might cause use-after-free bug. Signed-off-by: Li Zefan --- found when reading the code. --- mm/memcontrol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8ec501c..6391046 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3186,12 +3186,12 @@ void memcg_release_cache(struct kmem_cache *s) root = s->memcg_params->root_cache; root->memcg_params->memcg_caches[id] = NULL; - mem_cgroup_put(memcg); mutex_lock(&memcg->slab_caches_mutex); list_del(&s->memcg_params->list); mutex_unlock(&memcg->slab_caches_mutex); + mem_cgroup_put(memcg); out: kfree(s->memcg_params); } -- 1.8.0.2