linux-kernel - Re: [PATCH 0/5] i387: stable kernel backport

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

Message-ID: <20120223230430.GE1306@1wt.eu>
Date:	Fri, 24 Feb 2012 00:04:30 +0100
From:	Willy Tarreau <w@....eu>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Raphael Prevost <raphael@...o.asia>,
	Suresh Siddha <suresh.b.siddha@...el.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/5] i387: stable kernel backport

On Thu, Feb 23, 2012 at 02:55:11PM -0800, H. Peter Anvin wrote:
> On 02/23/2012 02:52 PM, Willy Tarreau wrote:
> > On Thu, Feb 23, 2012 at 02:48:51PM -0800, H. Peter Anvin wrote:
> >> On 02/23/2012 02:38 PM, Linus Torvalds wrote:
> >>>
> >>> You'd still need an x86-32 machine to test on, because x86-64 was
> >>> immune to this issue.
> >>>
> >>> But yeah, the impact of this seems to be small enough that for older
> >>> kernels (which are likely used on older systems for maintenance
> >>> anyway) disabling AES-NI on x86-32 really might be the way to go.
> >>>
> >>
> >> That would really suck for users of encrypted hard disks.
> > 
> > Peter, do you really think there are that many ? I think I only saw
> > AES-NI on recent 64-bit capable chips, and it's been a while that
> > users have been installing 64-bit distros on such machines. Note that
> > I'm not advocating for breaking existing setups, just that I'm surprized
> > by this combination (aes-ni + 32-bit).
> > 
> 
> There are still people running 32-bit systems because they have some odd
> compatibility constraints but now have to deal with corporate or other
> security constraints; they may also have been using disk encryption
> since before AES-NI was in but doing it on the integer side is way slower.

Indeed the combination looks plausible :-)

> This is not AES-NI in the interrupt path, but I don't think there is a
> knob for that.

OK. So let's hope this works then !

Willy

--
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/