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From: Ted Ts'o <tytso@mit.edu>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dan Rosenberg <drosenberg@vsecurity.com>,
	"chas@cmf.nrl.navy.mil" <chas@cmf.nrl.navy.mil>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"kuznet@ms2.inr.ac.ru" <kuznet@ms2.inr.ac.ru>,
	"pekkas@netcore.fi" <pekkas@netcore.fi>,
	"jmorris@namei.org" <jmorris@namei.org>,
	"yoshfuji@linux-ipv6.org" <yoshfuji@linux-ipv6.org>,
	"kaber@trash.net" <kaber@trash.net>,
	"remi.denis-courmont@nokia.com" <remi.denis-courmont@nokia.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"security@kernel.org" <security@kernel.org>
Subject: Re: [Security] [SECURITY] Fix leaking of kernel heap addresses via /proc
Date: Sat, 6 Nov 2010 19:48:40 -0400	[thread overview]
Message-ID: <20101106234840.GD2935@thunk.org> (raw)
In-Reply-To: <AANLkTimC01SViEOObgf2N2VcLTYO59rOAbHaKf2RM54w@mail.gmail.com>

On Sat, Nov 06, 2010 at 01:50:32PM -0700, Linus Torvalds wrote:
> On Saturday, November 6, 2010, Dan Rosenberg <drosenberg@vsecurity.com> wrote:
> > Clearly, in most cases we cannot just remove the field from the /proc
> > output, as this would break a number of userspace programs that rely on
> > consistency.  However, I propose that we replace the address with a "0"
> > rather than leaking this information.
> 
> I really think it would be much better to use the unidentified number
> or similar.
> 
> Just replacing with zeroes is annoying, and has the potential of
> losing actual information.

Are there any userspace programs that might be reasonably expected to
_use_ this information?  If there is, we could just pick a random
number at boot time, and then XOR the heap adddress with that random
number.

						- Ted

  reply	other threads:[~2010-11-06 23:49 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-06 20:11 [SECURITY] Fix leaking of kernel heap addresses via /proc Dan Rosenberg
2010-11-06 20:50 ` [Security] " Linus Torvalds
2010-11-06 23:48   ` Ted Ts'o [this message]
2010-11-07 21:52     ` Andi Kleen
2010-11-07 22:48       ` Chas Williams (CONTRACTOR)
2010-11-07 23:14         ` Andi Kleen
2010-11-07 23:22         ` Linus Torvalds
2010-11-07 23:29           ` Andi Kleen
2010-11-07 23:27         ` Dan Rosenberg
2010-11-07 23:56           ` Andi Kleen
2010-11-08  2:01             ` David Miller
2010-11-08  7:33               ` Eric Dumazet
2010-11-08  9:43                 ` Andi Kleen
2010-11-08 10:14                   ` Eric Dumazet
2010-11-06 23:57   ` David Miller
2010-11-07 10:28     ` Oliver Hartkopp
2010-11-07 17:11       ` Ben Hutchings
2010-11-08  1:00     ` Willy Tarreau

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