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Date:   Mon, 14 Sep 2020 11:18:44 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     Muchun Song <songmuchun@bytedance.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Cgroups <cgroups@vger.kernel.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [External] Re: [PATCH] mm: memcontrol: Fix out-of-bounds on the
 buf returned by memory_stat_format
Message-ID: <20200914091844.GE16999@dhcp22.suse.cz>
References: <20200912155100.25578-1-songmuchun@bytedance.com>
 <20200912174241.eeaa771755915f27babf9322@linux-foundation.org>
 <CAMZfGtXNg31+8QLbUMj7f61Yg1Jgt0rPB7VTDE7qoopGCANGjA@mail.gmail.com>
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On Mon 14-09-20 12:02:33, Muchun Song wrote:
> On Sun, Sep 13, 2020 at 8:42 AM Andrew Morton <akpm@linux-foundation.org> wrote:
> >
> > On Sat, 12 Sep 2020 23:51:00 +0800 Muchun Song <songmuchun@bytedance.com> wrote:
> >
> > > The memory_stat_format() returns a format string, but the return buf
> > > may not including the trailing '\0'. So the users may read the buf
> > > out of bounds.
> >
> > That sounds serious.  Is a cc:stable appropriate?
> >
> 
> Yeah, I think we should cc:stable.

Is this a real problem? The buffer should contain 36 lines which makes
it more than 100B per line. I strongly suspect we are not able to use
that storage up.
-- 
Michal Hocko
SUSE Labs