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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
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
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  parent reply index

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-09 21:11 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

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