linux-kernel - Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range

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: <20160106142237.GA16910@ares>
Date:	Wed, 6 Jan 2016 14:22:37 +0000
From:	Luis Henriques <luis.henriques@...onical.com>
To:	Matt Fleming <matt@...eblueprint.co.uk>
Cc:	Paolo Bonzini <pbonzini@...hat.com>, Jiri Slaby <jslaby@...e.cz>,
	stable@...r.kernel.org, linux-kernel@...r.kernel.org,
	Borislav Petkov <bp@...en8.de>,
	"H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...nel.org>,
	Andy Lutomirski <luto@...capital.net>,
	Kamal Mostafa <kamal@...onical.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover
 whole kernel range

[ Adding Greg and Kamal ]

On Wed, Jan 06, 2016 at 01:31:55PM +0000, Matt Fleming wrote:
> On Wed, 06 Jan, at 11:24:55AM, Luis Henriques wrote:
> > On Wed, Jan 06, 2016 at 11:00:31AM +0000, Matt Fleming wrote:
> > > On Wed, 06 Jan, at 11:47:20AM, Paolo Bonzini wrote:
> > > > 
> > > > Without testing the problematic scenario explicitly (32-bit UEFI
> > > > kernel), I think this patch and 26/91 should not be backported to
> > > > kernels that do not have 23a0d4e8fa6d.
> > > 
> > > I tend to agree.
> > 
> > I can see these 2 commits in kernels as old as 3.10 (which definitely do
> > not include 23a0d4e8fa6d).  Does this mean these should be reverted from
> > stable kernels that already include these patches?  Or would you rather
> > recommend to backport 23a0d4e8fa6d?
> 
> That depends on your appetite for risk ;-)
>

Heh, I guess stable kernels aren't really about appetite for risk :-)

> 23a0d4e8fa6d does fix a legitimate bug, albeit one that no one seems
> to have ever hit. Personally, I'd go for backporting 23a0d4e8fa6d.

This commit doesn't seem to be too bad to backport.  I'm attaching 2
backports:

 - one is for the 3.16 stable kernel,
 - the other can be applied to 3.10, 3.12 and 3.13

(For the other kernels, I believe 23a0d4e8fa6d will be a clean
cherry-pick.)

Cheers,
--
Luís

View attachment "3.10-efi-Disable-interrupts-around-EFI-calls-not-in-the-e.patch" of type "text/x-diff" (3664 bytes)

View attachment "3.16-efi-Disable-interrupts-around-EFI-calls-not-in-the-e.patch" of type "text/x-diff" (3834 bytes)