linux-kernel - Re: [PATCH 0/3] dm-crypt: Adds support for wiping key when doing suspend/hibernation

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: <20150423170211.GI7646@pali>
Date:	Thu, 23 Apr 2015 19:02:11 +0200
From:	Pali Rohár <pali.rohar@...il.com>
To:	Pavel Machek <pavel@....cz>
Cc:	Mike Snitzer <snitzer@...hat.com>,
	Alasdair Kergon <agk@...hat.com>, Neil Brown <neilb@...e.de>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Len Brown <len.brown@...el.com>, dm-devel@...hat.com,
	linux-raid@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org
Subject: Re: [PATCH 0/3] dm-crypt: Adds support for wiping key when doing
 suspend/hibernation

On Tuesday 14 April 2015 08:50:16 Pavel Machek wrote:
> Hi!
> 
> > > > > > So proper way is to wipe luks crypto keys *after* userspace processes
> > > > > > are freezed.
> > > > > 
> > > > > I know you believe that I'm just not accepting that at face value.
> > > > 
> > > > If disks are synced before any DM suspend operation then we have higher
> > > > chance of preventing data corruption.
> > > 
> > > disks are already synced as part of the DM suspend operation!
> > > 
> > 
> > Yes, but part of hibernate operation is also sync call.
> 
> Yes. Maybe that was a mistake.
> 

I think not. I do not see any reason why system should not sync disks...

> > > > I still think that correct order is only:
> > > > 
> > > > * freeze processes (which doing continous I/O)
> > > > * fs & disk sync
> > > > * DM suspend
> > > > * wipe crypto keys
> > > > * enter hibernate
> > > 
> > > I just don't think that extreme is _required_ to have a hibernate/resume
> > > that incorporates dm-crypt key wiping.
> > 
> > Ok, and what other developers think?
> 
> If someone can fix freezer to work with LUKS stopped, that would be a 
> good thing. Can you do it, Mike? Then we can look if it works well
> enough for Pali.
> 

Its not only LUKS devices. Its for all dm devices when are suspended.

> But that might be too hard / impossible. And at that point, I think
> Pali's patch is right thing to do.
> 									Pavel

Yes I think it is hard too...

-- 
Pali Rohár
pali.rohar@...il.com
--
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/