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Date:   Wed, 30 May 2018 13:52:46 +0200
From:   Michal Hocko <mhocko@kernel.org>
To:     "Eric W. Biederman" <ebiederm@xmission.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Kirill Tkhai <ktkhai@virtuozzo.com>, peterz@infradead.org,
        viro@zeniv.linux.org.uk, mingo@kernel.org,
        paulmck@linux.vnet.ibm.com, keescook@chromium.org, riel@redhat.com,
        tglx@linutronix.de, kirill.shutemov@linux.intel.com,
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        rppt@linux.vnet.ibm.com, linux-kernel@vger.kernel.org,
        Balbir Singh <balbir@linux.vnet.ibm.com>,
        Tejun Heo <tj@kernel.org>, Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH 0/2] mm->owner to mm->memcg fixes
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On Wed 23-05-18 14:46:43, Eric W. Biederman wrote:
[...]
> As two processes sharing an mm is useless and highly unlikely there is
> no need to handle this case well, it just needs to be handled well
> enough to prevent an indefinite loop.  So when css_tryget_online fails
> just treat the mm as belong to the root memory cgroup.

Does that mean that a malicious user can construct such a task and
runaway from its limits?

-- 
Michal Hocko
SUSE Labs