From: Pavel Machek <pavel@ucw.cz>
To: Yu Chen <yu.c.chen@intel.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Eric Biggers <ebiggers@google.com>,
"Lee, Chun-Yi" <jlee@suse.com>, Theodore Ts o <tytso@mit.edu>,
Stephan Mueller <smueller@chronox.de>,
Denis Kenzior <denkenz@gmail.com>,
linux-pm@vger.kernel.org, linux-crypto@vger.kernel.org,
linux-kernel@vger.kernel.org, "Gu, Kookoo" <kookoo.gu@intel.com>,
"Zhang, Rui" <rui.zhang@intel.com>
Subject: Re: [PATCH 0/4][RFC v2] Introduce the in-kernel hibernation encryption
Date: Fri, 20 Jul 2018 12:25:32 +0200 [thread overview]
Message-ID: <20180720102532.GA20284@amd> (raw)
In-Reply-To: <20180719132003.GA30981@sandybridge-desktop>
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Hi!
> > > > > As security becomes more and more important, we add the in-kernel
> > > > > encryption support for hibernation.
> > > >
> > > > Sorry, this does not really explain what security benefit it is
> > > > supposed have to against what attack scenarios.
> > > >
> > > > Which unfortunately means it can not reviewed.
> > > >
> > > > Note that uswsusp already provides encryption. If this is supposed to
> > > > have advantages over it, please say so.
> > > >
> > > The advantages are described in detail in
> > > [PATCH 1/4]'s log, please refer to that.
> >
> > Are you refering to this?
> >
> Not this one. I've sent v2 of this patch set which
> explain more on this:
> https://patchwork.kernel.org/patch/10532935/
Aha, sorry about that.
> Let me paste the log here:
>
> 1. (This is not to compare with uswsusp but other
> tools) One advantage is: Users do not have to
> encrypt the whole swap partition as other tools.
Well.. encrypting the partition seems like good idea anyway.
> 2. Ideally kernel memory should be encrypted by the
> kernel itself. We have uswsusp to support user
> space hibernation, however doing the encryption
> in kernel space has more advantages:
> 2.1 Not having to transfer plain text kernel memory to
> user space. Per Lee, Chun-Yi, uswsusp is disabled
> when the kernel is locked down:
> https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/
> linux-fs.git/commit/?h=lockdown-20180410&
> id=8732c1663d7c0305ae01ba5a1ee4d2299b7b4612
> due to:
> "There have some functions be locked-down because
> there have no appropriate mechanisms to check the
> integrity of writing data."
> https://patchwork.kernel.org/patch/10476751/
So your goal is to make hibernation compatible with kernel
lockdown? Do your patches provide sufficient security that hibernation
can be enabled with kernel lockdown?
> 2.2 Not having to copy each page to user space
> one by one not in parallel, which might introduce
> significant amount of copy_to_user() and it might
> not be efficient on servers having large amount of DRAM.
So how big speedup can be attributed by not doing copy_to_user?
> 2.3 Distribution has requirement to do snapshot
> signature for verification, which can be built
> by leveraging this patch set.
Signatures can be done by uswsusp, too, right?
> 2.4 The encryption is in the kernel, so it doesn't
> have to worry too much about bugs in user space
> utilities and similar, for example.
Answer to bugs in userspace is _not_ to move code from userspace to kernel.
> > Also note that joeyli <jlee@suse.com> has patch series which encrypts
> > both in-kernel and uswsusp hibernation methods. His motivation is
> > secure boot. How does this compare to his work?
> >
> Joey Lee and I had a discussion on his previous work at
> https://patchwork.kernel.org/patch/10476751
> We collaborate on this task and his snapshot signature
> feature can be based on this patch set.
Well, his work can also work without your patchset, right?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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next prev parent reply other threads:[~2018-07-20 10:25 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 16:38 [PATCH 0/4][RFC v2] Introduce the in-kernel hibernation encryption Chen Yu
2018-07-18 16:39 ` [PATCH 1/4][RFC v2] PM / Hibernate: Add helper functions for " Chen Yu
2018-07-18 16:39 ` [PATCH 2/4][RFC v2] PM / hibernate: Install crypto hooks " Chen Yu
2018-07-18 16:40 ` [PATCH 4/4][RFC v2] tools: create power/crypto utility Chen Yu
2018-07-18 20:22 ` [PATCH 0/4][RFC v2] Introduce the in-kernel hibernation encryption Pavel Machek
2018-07-18 23:58 ` Yu Chen
2018-07-19 11:01 ` Pavel Machek
2018-07-19 13:20 ` Yu Chen
2018-07-20 10:25 ` Pavel Machek [this message]
2018-07-23 11:42 ` Oliver Neukum
2018-07-23 12:22 ` Pavel Machek
2018-07-23 16:38 ` Yu Chen
2018-07-24 12:05 ` Pavel Machek
2018-07-24 11:49 ` Oliver Neukum
2018-07-24 13:04 ` Pavel Machek
2018-07-23 16:23 ` Yu Chen
2018-07-24 11:40 ` Oliver Neukum
2018-07-24 12:01 ` Pavel Machek
2018-07-24 12:47 ` Oliver Neukum
2018-07-24 13:03 ` Pavel Machek
2018-07-24 13:01 ` Oliver Neukum
2018-07-26 7:30 ` Oliver Neukum
2018-07-26 8:14 ` joeyli
2018-07-30 17:04 ` joeyli
2018-08-03 3:37 ` Yu Chen
2018-08-03 5:34 ` joeyli
2018-08-03 13:14 ` Ryan Chen
2018-08-03 14:05 ` joeyli
2018-08-03 16:09 ` Ryan Chen
2018-08-03 18:06 ` joeyli
2018-08-05 10:02 ` Pavel Machek
2018-08-06 8:45 ` Yu Chen
2018-08-06 10:39 ` joeyli
2018-08-07 7:43 ` Yu Chen
2018-08-07 16:27 ` joeyli
2018-08-08 17:58 ` Pavel Machek
2018-08-09 3:43 ` Yu Chen
2018-08-09 8:12 ` joeyli
2018-08-08 17:50 ` Pavel Machek
2018-08-09 3:01 ` Yu Chen
2018-08-09 6:53 ` Pavel Machek
2018-08-09 9:03 ` Oliver Neukum
2018-08-09 15:55 ` joeyli
2018-08-06 7:57 ` Yu Chen
2018-08-06 9:48 ` joeyli
2018-08-06 10:07 ` Yu Chen
2018-08-06 10:20 ` Oliver Neukum
2018-08-07 7:38 ` Yu Chen
2018-08-07 7:49 ` Ryan Chen
2018-08-07 10:04 ` Oliver Neukum
2018-07-24 14:47 ` joeyli
2018-07-19 14:58 ` joeyli
[not found] ` <edf92acf665b928f02104bb1835fd50723ab9980.1531924968.git.yu.c.chen@intel.com>
2018-07-19 5:32 ` [PATCH 3/4][RFC v2] PM / Hibernate: Encrypt the snapshot pages before submitted to the block device Yu Chen
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