linux-kernel - Re: Is kernel optimized with dead store removal?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Thu, 25 Feb 2010 20:58:01 -0300
From:	Henrique de Moraes Holschuh <hmh@....eng.br>
To:	Mikael Pettersson <mikpe@...uu.se>
Cc:	Roel Kluin <roel.kluin@...il.com>,
	lkml <linux-kernel@...r.kernel.org>,
	Herbert Xu <herbert@...dor.apana.org.au>,
	"David S. Miller" <davem@...emloft.net>,
	linux-crypto@...r.kernel.org
Subject: Re: Is kernel optimized with dead store removal?

On Thu, 25 Feb 2010, Mikael Pettersson wrote:
>  > In the sha1_update() case I don't know whether the stack is recycled and
>  > leaked - it may be dependent on the calling function, but isn't it
>  > vulnerable?
> 
> It's only vulnerable if the data leaks to a less trusted domain.

If it is anything you wanted to protect badly enough that you already have
code to clobber it later, this *is* a security bug.

Not only you remove one layer of security, you also widen a lot the window
of opportunity to, e.g., http://en.wikipedia.org/wiki/Cold_boot_attack

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/