From: Miaohe Lin <linmiaohe@huawei.com> To: <hannes@cmpxchg.org>, <mhocko@kernel.org>, <vdavydov.dev@gmail.com>, <akpm@linux-foundation.org> Cc: <shakeelb@google.com>, <guro@fb.com>, <willy@infradead.org>, <alexs@kernel.org>, <richard.weiyang@gmail.com>, <songmuchun@bytedance.com>, <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>, <cgroups@vger.kernel.org>, <linmiaohe@huawei.com> Subject: [PATCH 4/5] mm, memcg: avoid possible NULL pointer dereferencing in mem_cgroup_init() Date: Thu, 29 Jul 2021 20:57:54 +0800 [thread overview] Message-ID: <20210729125755.16871-5-linmiaohe@huawei.com> (raw) In-Reply-To: <20210729125755.16871-1-linmiaohe@huawei.com> rtpn might be NULL in very rare case. We have better to check it before dereferencing it. Since memcg can live with NULL rb_tree_per_node in soft_limit_tree, warn this case and continue. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- mm/memcontrol.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5b4592d1e0f2..70a32174e7c4 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -7109,6 +7109,8 @@ static int __init mem_cgroup_init(void) rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, node_online(node) ? node : NUMA_NO_NODE); + if (WARN_ON_ONCE(!rtpn)) + continue; rtpn->rb_root = RB_ROOT; rtpn->rb_rightmost = NULL; spin_lock_init(&rtpn->lock); -- 2.23.0
WARNING: multiple messages have this Message-ID (diff)
From: Miaohe Lin <linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> To: hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org Cc: shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, guro-b10kYP2dOMg@public.gmane.org, willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, alexs-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org Subject: [PATCH 4/5] mm, memcg: avoid possible NULL pointer dereferencing in mem_cgroup_init() Date: Thu, 29 Jul 2021 20:57:54 +0800 [thread overview] Message-ID: <20210729125755.16871-5-linmiaohe@huawei.com> (raw) In-Reply-To: <20210729125755.16871-1-linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> rtpn might be NULL in very rare case. We have better to check it before dereferencing it. Since memcg can live with NULL rb_tree_per_node in soft_limit_tree, warn this case and continue. Signed-off-by: Miaohe Lin <linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> --- mm/memcontrol.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5b4592d1e0f2..70a32174e7c4 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -7109,6 +7109,8 @@ static int __init mem_cgroup_init(void) rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, node_online(node) ? node : NUMA_NO_NODE); + if (WARN_ON_ONCE(!rtpn)) + continue; rtpn->rb_root = RB_ROOT; rtpn->rb_rightmost = NULL; spin_lock_init(&rtpn->lock); -- 2.23.0
next prev parent reply other threads:[~2021-07-29 12:58 UTC|newest] Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-29 12:57 [PATCH 0/5] Cleanups and fixup for memcontrol Miaohe Lin 2021-07-29 12:57 ` Miaohe Lin 2021-07-29 12:57 ` [PATCH 1/5] mm, memcg: remove unused functions Miaohe Lin 2021-07-29 12:57 ` Miaohe Lin 2021-07-29 14:07 ` Shakeel Butt 2021-07-29 14:07 ` Shakeel Butt 2021-07-29 14:07 ` Shakeel Butt 2021-07-30 2:39 ` Muchun Song 2021-07-30 2:39 ` Muchun Song 2021-07-30 2:39 ` Muchun Song 2021-07-30 2:57 ` Roman Gushchin 2021-07-30 2:57 ` Roman Gushchin 2021-07-30 6:45 ` Michal Hocko 2021-07-30 6:45 ` Michal Hocko 2021-07-29 12:57 ` [PATCH 2/5] mm, memcg: narrow the scope of percpu_charge_mutex Miaohe Lin 2021-07-29 12:57 ` Miaohe Lin 2021-07-30 2:42 ` Muchun Song 2021-07-30 2:42 ` Muchun Song 2021-07-30 2:42 ` Muchun Song 2021-07-30 3:06 ` Roman Gushchin 2021-07-30 3:06 ` Roman Gushchin 2021-07-30 6:50 ` Michal Hocko 2021-07-30 6:50 ` Michal Hocko 2021-07-31 2:29 ` Miaohe Lin 2021-07-31 2:29 ` Miaohe Lin 2021-08-02 6:49 ` Michal Hocko 2021-08-02 6:49 ` Michal Hocko 2021-08-02 9:54 ` Miaohe Lin 2021-08-02 9:54 ` Miaohe Lin 2021-08-03 3:40 ` Roman Gushchin 2021-08-03 3:40 ` Roman Gushchin 2021-08-03 6:29 ` Miaohe Lin 2021-08-03 6:29 ` Miaohe Lin 2021-08-03 7:11 ` Michal Hocko 2021-08-03 7:11 ` Michal Hocko 2021-08-03 7:13 ` Roman Gushchin 2021-08-03 7:13 ` Roman Gushchin 2021-08-03 7:27 ` Michal Hocko 2021-08-03 7:27 ` Michal Hocko 2021-08-03 9:33 ` Muchun Song 2021-08-03 9:33 ` Muchun Song 2021-08-03 9:33 ` Muchun Song 2021-08-03 10:50 ` Miaohe Lin 2021-08-03 10:50 ` Miaohe Lin 2021-08-03 14:15 ` Johannes Weiner 2021-08-03 14:15 ` Johannes Weiner 2021-08-04 8:20 ` Michal Hocko 2021-08-04 8:20 ` Michal Hocko 2021-08-05 1:44 ` Miaohe Lin 2021-08-05 1:44 ` Miaohe Lin 2021-07-30 6:46 ` Michal Hocko 2021-07-29 12:57 ` [PATCH 3/5] mm, memcg: save some atomic ops when flush is already true Miaohe Lin 2021-07-29 12:57 ` Miaohe Lin 2021-07-29 14:40 ` Shakeel Butt 2021-07-29 14:40 ` Shakeel Butt 2021-07-29 14:40 ` Shakeel Butt 2021-07-30 2:37 ` Muchun Song 2021-07-30 2:37 ` Muchun Song 2021-07-30 2:37 ` Muchun Song 2021-07-30 3:07 ` Roman Gushchin 2021-07-30 3:07 ` Roman Gushchin 2021-07-30 6:51 ` Michal Hocko 2021-07-30 6:51 ` Michal Hocko 2021-07-29 12:57 ` Miaohe Lin [this message] 2021-07-29 12:57 ` [PATCH 4/5] mm, memcg: avoid possible NULL pointer dereferencing in mem_cgroup_init() Miaohe Lin 2021-07-29 13:52 ` Matthew Wilcox 2021-07-29 13:52 ` Matthew Wilcox 2021-07-30 1:50 ` Miaohe Lin 2021-07-30 1:50 ` Miaohe Lin 2021-07-30 3:12 ` Roman Gushchin 2021-07-30 3:12 ` Roman Gushchin 2021-07-30 6:29 ` Miaohe Lin 2021-07-30 6:29 ` Miaohe Lin 2021-07-30 6:44 ` Michal Hocko 2021-07-30 6:44 ` Michal Hocko 2021-07-31 2:05 ` Miaohe Lin 2021-07-31 2:05 ` Miaohe Lin 2021-08-02 6:43 ` Michal Hocko 2021-08-02 6:43 ` Michal Hocko 2021-08-02 10:00 ` Miaohe Lin 2021-08-02 10:00 ` Miaohe Lin 2021-08-02 10:42 ` Michal Hocko 2021-08-02 10:42 ` Michal Hocko 2021-08-02 11:18 ` Miaohe Lin 2021-08-02 11:18 ` Miaohe Lin 2021-07-29 12:57 ` [PATCH 5/5] mm, memcg: always call __mod_node_page_state() with preempt disabled Miaohe Lin 2021-07-29 12:57 ` Miaohe Lin 2021-07-29 14:39 ` Shakeel Butt 2021-07-29 14:39 ` Shakeel Butt 2021-07-29 14:39 ` Shakeel Butt 2021-07-30 1:52 ` Miaohe Lin 2021-07-30 1:52 ` Miaohe Lin 2021-07-30 2:33 ` [External] " Muchun Song 2021-07-30 2:33 ` Muchun Song 2021-07-30 2:33 ` Muchun Song 2021-07-30 2:46 ` Miaohe Lin 2021-07-30 2:46 ` Miaohe Lin
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