All of lore.kernel.org
 help / color / mirror / Atom feed
From: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
To: David Gens <david.gens@cs.tu-darmstadt.de>,
	Thomas Garnier <thgarnie@google.com>
Cc: kernel list <linux-kernel@vger.kernel.org>,
	Kernel Hardening <kernel-hardening@lists.openwall.com>,
	<clementine.maurice@iaik.tugraz.at>, <moritz.lipp@iaik.tugraz.at>,
	Michael Schwarz <michael.schwarz@iaik.tugraz.at>,
	Richard Fellner <richard.fellner@student.tugraz.at>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Ingo Molnar <mingo@kernel.org>, <anders.fogh@gdata-adan.de>
Subject: Re: [kernel-hardening] [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode
Date: Mon, 8 May 2017 15:53:20 +0200	[thread overview]
Message-ID: <62c69fb5-03a8-4f30-cbc1-4955e9efbb18@iaik.tugraz.at> (raw)
In-Reply-To: <a7cc85fd-b261-0c83-8636-eb57c9ba71f9@iaik.tugraz.at>

On 06.05.2017 10:38, Daniel Gruss wrote:
> On 2017-05-06 06:02, David Gens wrote:
>> Assuming that their patch indeed leaks per-cpu addresses.. it might not
>> necessarily
>> be required to change it.
>
> I think we're not leaking them (unless we still have some bug in our code).

Just to correct my answer here as well: Although we experimented with fixed mappings for per-cpu addresses, the current 
patch does not incorporate this yet, so it indeed still leaks. However, it is not a severe problem. The mapping of the 
required (per-cpu) variables would be at a fixed location in the user CR3, instead of the ones that are used in the kernel.

WARNING: multiple messages have this Message-ID (diff)
From: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
To: David Gens <david.gens@cs.tu-darmstadt.de>,
	Thomas Garnier <thgarnie@google.com>
Cc: kernel list <linux-kernel@vger.kernel.org>,
	Kernel Hardening <kernel-hardening@lists.openwall.com>,
	clementine.maurice@iaik.tugraz.at, moritz.lipp@iaik.tugraz.at,
	Michael Schwarz <michael.schwarz@iaik.tugraz.at>,
	Richard Fellner <richard.fellner@student.tugraz.at>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Ingo Molnar <mingo@kernel.org>,
	anders.fogh@gdata-adan.de
Subject: Re: [kernel-hardening] [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode
Date: Mon, 8 May 2017 15:53:20 +0200	[thread overview]
Message-ID: <62c69fb5-03a8-4f30-cbc1-4955e9efbb18@iaik.tugraz.at> (raw)
In-Reply-To: <a7cc85fd-b261-0c83-8636-eb57c9ba71f9@iaik.tugraz.at>

On 06.05.2017 10:38, Daniel Gruss wrote:
> On 2017-05-06 06:02, David Gens wrote:
>> Assuming that their patch indeed leaks per-cpu addresses.. it might not
>> necessarily
>> be required to change it.
>
> I think we're not leaking them (unless we still have some bug in our code).

Just to correct my answer here as well: Although we experimented with fixed mappings for per-cpu addresses, the current 
patch does not incorporate this yet, so it indeed still leaks. However, it is not a severe problem. The mapping of the 
required (per-cpu) variables would be at a fixed location in the user CR3, instead of the ones that are used in the kernel.

  parent reply	other threads:[~2017-05-08 13:53 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-04 10:02 [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode Daniel Gruss
2017-05-04 10:02 ` [kernel-hardening] " Daniel Gruss
2017-05-04 12:26 ` Daniel Gruss
2017-05-04 12:26   ` [kernel-hardening] " Daniel Gruss
2017-05-04 15:28 ` [kernel-hardening] " Thomas Garnier
2017-05-04 15:28   ` Thomas Garnier
2017-05-05  8:23   ` Daniel Gruss
2017-05-05  8:23     ` Daniel Gruss
2017-05-05 15:47     ` Thomas Garnier
2017-05-05 15:47       ` Thomas Garnier
2017-05-06  4:02       ` David Gens
2017-05-06  8:38         ` Daniel Gruss
2017-05-06  8:38           ` Daniel Gruss
2017-05-08 10:21           ` Mark Rutland
2017-05-08 10:51             ` Daniel Gruss
2017-05-08 10:51               ` Daniel Gruss
2017-05-08 13:22               ` Mark Rutland
2017-05-08 13:43                 ` Daniel Gruss
2017-05-08 13:43                   ` Daniel Gruss
2017-05-08 13:53           ` Daniel Gruss [this message]
2017-05-08 13:53             ` Daniel Gruss
2017-05-08 14:09             ` Thomas Garnier
2017-05-08 14:19               ` Daniel Gruss
2017-05-08 14:19                 ` Daniel Gruss
2017-05-08 13:23     ` Daniel Gruss
2017-05-08 13:23       ` Daniel Gruss
2017-05-04 15:47 ` Christoph Hellwig
2017-05-04 15:47   ` [kernel-hardening] " Christoph Hellwig
2017-05-05  7:40   ` Daniel Gruss
2017-05-05  7:40     ` [kernel-hardening] " Daniel Gruss
2017-05-07 20:20     ` Richard Weinberger
2017-05-07 20:20       ` Richard Weinberger
2017-05-07 21:45       ` Daniel Gruss
2017-05-07 21:45         ` Daniel Gruss
2017-05-07 22:02         ` Richard Weinberger
2017-05-07 22:02           ` Richard Weinberger
2017-05-07 22:18           ` Daniel Gruss
2017-05-07 22:18             ` Daniel Gruss
2017-05-09 14:44             ` [kernel-hardening] Re: [RFC, PATCH] x86_64: KAISER - do not mapkernel " Fogh, Anders
2017-05-09 14:44               ` Fogh, Anders
2017-05-09 14:57               ` Richard Weinberger
2017-05-09 14:57                 ` Richard Weinberger
2017-05-09 15:30                 ` Rik van Riel
2017-05-09 15:30                   ` Rik van Riel
2017-10-31 23:28                   ` Dave Hansen
2017-10-31 23:28                     ` Dave Hansen
2017-05-05 15:49 ` [kernel-hardening] [RFC, PATCH] x86_64: KAISER - do not map kernel " Jann Horn
2017-05-05 15:49   ` Jann Horn
2017-05-05 15:53   ` Jann Horn
2017-05-05 15:53     ` Jann Horn
2017-05-06  8:28     ` Daniel Gruss
2017-05-06  8:28       ` Daniel Gruss

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=62c69fb5-03a8-4f30-cbc1-4955e9efbb18@iaik.tugraz.at \
    --to=daniel.gruss@iaik.tugraz.at \
    --cc=anders.fogh@gdata-adan.de \
    --cc=clementine.maurice@iaik.tugraz.at \
    --cc=david.gens@cs.tu-darmstadt.de \
    --cc=kernel-hardening@lists.openwall.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=michael.schwarz@iaik.tugraz.at \
    --cc=mingo@kernel.org \
    --cc=moritz.lipp@iaik.tugraz.at \
    --cc=richard.fellner@student.tugraz.at \
    --cc=thgarnie@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.