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From: Kees Cook <keescook@google.com>
To: Arjan van de Ven <arjan@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>,
	"dwmw@amazon.co.uk" <dwmw@amazon.co.uk>,
	"riel@redhat.com" <riel@redhat.com>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"tim.c.chen@linux.intel.com" <tim.c.chen@linux.intel.com>,
	"pjt@google.com" <pjt@google.com>,
	"jpoimboe@redhat.com" <jpoimboe@redhat.com>,
	"ak@linux.intel.com" <ak@linux.intel.com>,
	"gregkh@linux-foundation.org" <gregkh@linux-foundation.org>,
	"torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
	"dave.hansen@intel.com" <dave.hansen@intel.com>,
	"luto@amacapital.net" <luto@amacapital.net>,
	"jikos@kernel.org" <jikos@kernel.org>,
	"peterz@infradead.org" <peterz@infradead.org>,
	"mingo@kernel.org" <mingo@kernel.org>,
	"hpa@zytor.com" <hpa@zytor.com>,
	"linux-tip-commits@vger.kernel.org" 
	<linux-tip-commits@vger.kernel.org>
Subject: Re: [tip:x86/pti] x86/retpoline: Fill RSB on context switch for affected CPUs
Date: Mon, 15 Jan 2018 12:03:45 -0800	[thread overview]
Message-ID: <CAGXu5jK=-9oQPPxtjU0wKRyae2W=M2TP4zJaY3RwcrRvQ1Efnw@mail.gmail.com> (raw)
In-Reply-To: <db67ffe2-ee2b-2295-de8e-a1738c661c6e@linux.intel.com>

On Mon, Jan 15, 2018 at 6:42 AM, Arjan van de Ven <arjan@linux.intel.com> wrote:
>>
>> This would means that userspace would see return predictions based
>> on the values the kernel 'stuffed' into the RSB to fill it.
>>
>> Potentially this leaks a kernel address to userspace.
>
>
> KASLR pretty much died in May this year to be honest with the KAISER paper
> (if not before then)

KASLR was always on shaky ground for local attacks. For pure remote
attacks, it's still useful. And for driving forward research, it
appears to be quite useful. ;)

-Kees

-- 
Kees Cook
Pixel Security

  reply	other threads:[~2018-01-15 20:03 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-12 17:49 [PATCH] x86/retpoline: Fill RSB on context switch for affected CPUs David Woodhouse
2018-01-12 18:02 ` Andi Kleen
2018-01-12 18:23   ` David Woodhouse
2018-01-12 18:05 ` Andrew Cooper
2018-01-12 18:56   ` David Woodhouse
2018-01-12 23:41     ` Josh Poimboeuf
2018-01-14 11:39 ` Thomas Gleixner
2018-01-14 17:04 ` [tip:x86/pti] " tip-bot for David Woodhouse
2018-01-15 14:35   ` David Laight
2018-01-15 14:39     ` David Woodhouse
2018-01-15 14:42     ` Arjan van de Ven
2018-01-15 20:03       ` Kees Cook [this message]
2018-01-14 23:37 ` tip-bot for David Woodhouse
2018-01-15  0:05   ` Andi Kleen
2018-01-15  0:09     ` Andi Kleen
2018-01-15 10:13     ` David Woodhouse
2018-03-09 13:12 ` Maciej S. Szmigiero
2018-03-09 15:14   ` Andi Kleen
2018-03-09 15:33     ` Maciej S. Szmigiero
2018-03-09 15:38     ` Woodhouse, David

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