From: Kees Cook <keescook@chromium.org>
To: Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>
Cc: Rik van Riel <riel@redhat.com>, Tycho Andersen <tycho@docker.com>,
Laura Abbott <labbott@redhat.com>,
Daniel Micay <danielmicay@gmail.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Ingo Molnar <mingo@kernel.org>,
Josh Triplett <josh@joshtriplett.org>,
Andy Lutomirski <luto@kernel.org>,
Nicolas Pitre <nicolas.pitre@linaro.org>,
Tejun Heo <tj@kernel.org>, Daniel Mack <daniel@zonque.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Helge Deller <deller@gmx.de>, LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Subject: Re: [kernel-hardening] Re: [PATCH v2] mm: Add SLUB free list pointer obfuscation
Date: Wed, 5 Jul 2017 16:30:56 -0700 [thread overview]
Message-ID: <CAGXu5j+6Bq1YW9EPWGxjbz4bWWf7PvoKi5pbp6sNz8fvkq9ncw@mail.gmail.com> (raw)
In-Reply-To: <20170629175647.pufnks75fqy627jv@smitten>
On Thu, Jun 29, 2017 at 10:56 AM, Tycho Andersen <tycho@docker.com> wrote:
> On Thu, Jun 29, 2017 at 01:54:13PM -0400, Rik van Riel wrote:
>> On Thu, 2017-06-29 at 10:47 -0700, Kees Cook wrote:
>> > On Thu, Jun 29, 2017 at 10:05 AM, Christoph Lameter <cl@linux.com>
>> > wrote:
>> > > On Sun, 25 Jun 2017, Kees Cook wrote:
>> > >
>> > > > The difference gets lost in the noise, but if the above is
>> > > > sensible,
>> > > > it's 0.07% slower. ;)
>> > >
>> > > Hmmm... These differences add up. Also in a repetative benchmark
>> > > like that
>> > > you do not see the impact that the additional cacheline use in the
>> > > cpu
>> > > cache has on larger workloads. Those may be pushed over the edge of
>> > > l1 or
>> > > l2 capacity at some point which then causes drastic regressions.
>> >
>> > Even if that is true, it may be worth it to some people to have the
>> > protection. Given that is significantly hampers a large class of heap
>> > overflow attacks[1], I think it's an important change to have. I'm
>> > not
>> > suggesting this be on by default, it's cleanly behind
>> > CONFIG-controlled macros, and is very limited in scope. If you can
>> > Ack
>> > it we can let system builders decide if they want to risk a possible
>> > performance hit. I'm pretty sure most distros would like to have this
>> > protection.
>>
>> I could certainly see it being useful for all kinds of portable
>> and network-connected systems where security is simply much
>> more important than performance.
>
> Indeed, I believe we would enable this in our kernels.
Andrew and Christoph,
What do you think about carrying this for -mm, since people are
interested in it and it's a very narrow change behind a config (with a
large impact on reducing the expoitability of freelist pointer
overwrites)?
-Kees
--
Kees Cook
Pixel Security
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next prev parent reply other threads:[~2017-07-05 23:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-23 1:50 Kees Cook
2017-06-25 19:56 ` Kees Cook
2017-06-29 17:05 ` Christoph Lameter
2017-06-29 17:47 ` Kees Cook
2017-06-29 17:54 ` Rik van Riel
2017-06-29 17:56 ` [kernel-hardening] " Tycho Andersen
2017-07-05 23:30 ` Kees Cook [this message]
2017-07-05 23:39 ` Andrew Morton
2017-07-05 23:56 ` Kees Cook
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