linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Pavel Machek <pavel@ucw.cz>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Pavel Emelyanov <xemul@parallels.com>,
	Konstantin Khlebnikov <khlebnikov@openvz.org>,
	Mark Seaborn <mseaborn@chromium.org>,
	Andy Lutomirski <luto@amacapital.net>
Subject: Re: [RFC, PATCH] pagemap: do not leak physical addresses to non-privileged userspace
Date: Mon, 16 Mar 2015 22:11:22 +0100	[thread overview]
Message-ID: <20150316211122.GD11441@amd> (raw)
In-Reply-To: <1425935472-17949-1-git-send-email-kirill@shutemov.name>

On Mon 2015-03-09 23:11:12, Kirill A. Shutemov wrote:
> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
> 
> As pointed by recent post[1] on exploiting DRAM physical imperfection,
> /proc/PID/pagemap exposes sensitive information which can be used to do
> attacks.
> 
> This is RFC patch which disallow anybody without CAP_SYS_ADMIN to read
> the pagemap.
> 
> Any comments?
> 
> [1]
http://googleprojectzero.blogspot.com/2015/03/exploiting-dram-rowhammer-bug-to-gain.html

Note that this kind of attack still works without pagemap, it just
takes longer. Actually the first demo program is not using pagemap.

Can we do anything about that? Disabling cache flushes from userland
should make it no longer exploitable.
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

  parent reply	other threads:[~2015-03-16 21:11 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-09 21:11 [RFC, PATCH] pagemap: do not leak physical addresses to non-privileged userspace Kirill A. Shutemov
2015-03-09 21:20 ` Pavel Emelyanov
2015-03-09 22:09 ` Konstantin Khlebnikov
2015-03-10  0:11 ` Kees Cook
2015-03-10  0:19   ` Andy Lutomirski
2015-03-10  2:36     ` Dave Hansen
2015-03-16 21:11 ` Pavel Machek [this message]
2015-03-17  0:49   ` Mark Seaborn
2015-03-17  1:21     ` Andy Lutomirski
2015-03-17 11:16       ` rowhammer and pagemap (was Re: [RFC, PATCH] pagemap: do not leak physical addresses to non-privileged userspace) Pavel Machek
2015-03-17 17:58         ` One Thousand Gnomes
2015-03-23 21:26           ` Pavel Machek
2015-03-19 12:51       ` [RFC, PATCH] pagemap: do not leak physical addresses to non-privileged userspace Vlastimil Babka
2015-03-23 21:26         ` Pavel Machek
2015-03-23 22:36           ` Vlastimil Babka

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=20150316211122.GD11441@amd \
    --to=pavel@ucw.cz \
    --cc=akpm@linux-foundation.org \
    --cc=khlebnikov@openvz.org \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=kirill@shutemov.name \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=luto@amacapital.net \
    --cc=mseaborn@chromium.org \
    --cc=torvalds@linux-foundation.org \
    --cc=xemul@parallels.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).