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;
Date:   Mon, 5 Oct 2020 10:22:52 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     Topi Miettinen <toiwoton@gmail.com>
Cc:     David Hildenbrand <david@redhat.com>, akpm@linux-foundation.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: optionally disable brk()
Message-ID: <20201005082239.GQ4555@dhcp22.suse.cz>
References: <20201002171921.3053-1-toiwoton@gmail.com>
 <653873ef-2a57-37e0-1ac3-fba763652b35@redhat.com>
 <2a0f5ade-d770-c36e-50bc-ff0c8e9dacbf@gmail.com>
 <20201005061248.GN4555@dhcp22.suse.cz>
 <7d7b1ac5-d6a7-5e43-8fb8-12b844d7f501@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <7d7b1ac5-d6a7-5e43-8fb8-12b844d7f501@gmail.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk

On Mon 05-10-20 11:11:35, Topi Miettinen wrote:
[...]
> I think hardened, security oriented systems should disable brk() completely
> because it will increase the randomization of the process address space
> (ASLR). This wouldn't be a good option to enable for systems where maximum
> compatibility with legacy software is more important than any hardening.

I believe we already do have means to filter syscalls from userspace for
security hardened environements. Or is there any reason to duplicate
that and control during the configuration time?
-- 
Michal Hocko
SUSE Labs