From: Tycho Andersen <tycho@docker.com>
To: Rik van Riel <riel@redhat.com>
Cc: Kees Cook <keescook@chromium.org>,
Christoph Lameter <cl@linux.com>,
Andrew Morton <akpm@linux-foundation.org>,
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: Thu, 29 Jun 2017 11:56:47 -0600 [thread overview]
Message-ID: <20170629175647.pufnks75fqy627jv@smitten> (raw)
In-Reply-To: <1498758853.6130.2.camel@redhat.com>
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.
Cheers,
Tycho
next prev parent reply other threads:[~2017-06-29 17:56 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-23 1:50 [PATCH v2] mm: Add SLUB free list pointer obfuscation 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 ` Tycho Andersen [this message]
2017-07-05 23:30 ` [kernel-hardening] " Kees Cook
2017-07-05 23:39 ` Andrew Morton
2017-07-05 23:56 ` Kees Cook
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