From: Evan Green <evgreen@chromium.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>, LKML <linux-kernel@vger.kernel.org>,
Matthew Garrett <mgarrett@aurora.tech>,
Daniil Lunev <dlunev@google.com>,
zohar@linux.ibm.com, "James E.J. Bottomley" <jejb@linux.ibm.com>,
linux-integrity@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Gwendal Grignou <gwendal@chromium.org>,
Jarkko Sakkinen <jarkko@kernel.org>,
Linux PM <linux-pm@vger.kernel.org>,
David Howells <dhowells@redhat.com>, Hao Wu <hao.wu@rubrik.com>,
James Morris <jmorris@namei.org>, Jason Gunthorpe <jgg@ziepe.ca>,
Len Brown <len.brown@intel.com>,
Matthew Garrett <matthewgarrett@google.com>,
Peter Huewe <peterhuewe@gmx.de>,
"Serge E. Hallyn" <serge@hallyn.com>, axelj <axelj@axis.com>,
keyrings@vger.kernel.org,
"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
linux-security-module@vger.kernel.org
Subject: Re: [PATCH 00/10] Encrypted Hibernation
Date: Tue, 17 May 2022 10:34:05 -0700 [thread overview]
Message-ID: <CAE=gft6V6RLc-d4AOuRUVU2u1jMGghDRSrFqiCqMCLxemui8Pw@mail.gmail.com> (raw)
In-Reply-To: <CAJZ5v0gxq=EA_WWUiCR_w8o87iTHDR7OC5wi=GRBaAQS2ofd5w@mail.gmail.com>
Hi Rafael,
On Tue, May 17, 2022 at 9:06 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> On Mon, May 9, 2022 at 6:44 PM Evan Green <evgreen@chromium.org> wrote:
> >
> > On Fri, May 6, 2022 at 9:08 AM Pavel Machek <pavel@ucw.cz> wrote:
> > >
> > > Hi!
> > >
> > > > We are exploring enabling hibernation in some new scenarios. However,
> > > > our security team has a few requirements, listed below:
> > > > 1. The hibernate image must be encrypted with protection derived from
> > > > both the platform (eg TPM) and user authentication data (eg
> > > > password).
> > > > 2. Hibernation must not be a vector by which a malicious userspace can
> > > > escalate to the kernel.
> > >
> > > Can you (or your security team) explain why requirement 2. is needed?
> > >
> > > On normal systems, trusted userspace handles kernel upgrades (for example),
> > > so it can escalate to kernel priviledges.
> > >
> >
> > Our systems are a little more sealed up than a normal distro, we use
> > Verified Boot [1]. To summarize, RO firmware with an embedded public
> > key verifies that the kernel+commandline was signed by Google. The
> > commandline includes the root hash of the rootfs as well (where the
> > modules live). So when an update is applied (A/B style, including the
> > whole rootfs), assuming the RO firmware stayed RO (which requires
> > physical measures to defeat), we can guarantee that the kernel,
> > commandline, and rootfs have not been tampered with.
> >
> > Verified boot gives us confidence that on each boot, we're at least
> > starting from known code. This makes it more challenging for an
> > attacker to persist an exploit across reboot. With the kernel and
> > modules verified, we try to make it non-trivial for someone who does
> > manage to gain root execution once from escalating to kernel
> > execution. Hibernation would be one obvious escalation route, so we're
> > hoping to find a way to enable it without handing out that easy
> > primitive.
> >
> > [1] https://www.chromium.org/chromium-os/chromiumos-design-docs/verified-boot/
>
> So I guess this really is an RFC.
Yes, I suppose it is.
>
> Honestly, I need more time to go through this and there are pieces of
> it that need to be looked at other people (like the TPM-related
> changes).
No problem, thanks for the reply to let me know. I expect some back
and forth in terms of what should be hidden behind abstractions and
where exactly things should live. But I wanted to get this out to
upstream as early as I could, just to get initial reactions on the
overall concept and design. Looking forward to hearing your thoughts
when you get a chance, and let me know if there are others I should be
adding that I've missed.
-Evan
>
> Thanks!
next prev parent reply other threads:[~2022-05-17 17:42 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-04 23:20 [PATCH 00/10] Encrypted Hibernation Evan Green
2022-05-04 23:20 ` [PATCH 01/10] tpm: Add support for in-kernel resetting of PCRs Evan Green
2022-05-04 23:20 ` [PATCH 02/10] tpm: Allow PCR 23 to be restricted to kernel-only use Evan Green
2022-05-04 23:20 ` [PATCH 03/10] security: keys: trusted: Parse out individual components of the key blob Evan Green
2022-05-04 23:20 ` [PATCH 04/10] security: keys: trusted: Allow storage of PCR values in creation data Evan Green
2022-08-02 23:00 ` Eric Biggers
2022-08-03 20:48 ` Evan Green
2022-05-04 23:20 ` [PATCH 05/10] security: keys: trusted: Verify " Evan Green
2022-05-04 23:20 ` [PATCH 06/10] PM: hibernate: Add kernel-based encryption Evan Green
2022-08-29 21:45 ` TPM: hibernate with IMA PCR 10 Ken Goldman
2022-08-29 21:51 ` Matthew Garrett
2022-08-31 2:48 ` Jarkko Sakkinen
2022-09-07 20:47 ` Evan Green
2022-09-07 23:57 ` Mimi Zohar
2022-09-08 5:25 ` Jarkko Sakkinen
2022-09-11 2:40 ` Mimi Zohar
2022-09-20 4:36 ` Jarkko Sakkinen
2022-09-21 20:15 ` Mimi Zohar
2022-09-23 13:30 ` Jarkko Sakkinen
2022-09-27 16:03 ` Evan Green
2022-09-28 9:42 ` Jonathan McDowell
2022-05-04 23:20 ` [PATCH 07/10] PM: hibernate: Use TPM-backed keys to encrypt image Evan Green
2022-05-04 23:21 ` [PATCH 08/10] PM: hibernate: Mix user key in encrypted hibernate Evan Green
2022-05-06 16:08 ` Pavel Machek
2022-05-09 16:44 ` Evan Green
2022-05-10 12:29 ` Pavel Machek
2022-05-10 16:02 ` Evan Green
2022-08-02 22:48 ` Eric Biggers
2022-08-03 20:48 ` Evan Green
2022-05-04 23:21 ` [PATCH 09/10] PM: hibernate: Verify the digest encryption key Evan Green
2022-08-02 22:51 ` Eric Biggers
2022-05-04 23:21 ` [PATCH 10/10] PM: hibernate: seal the encryption key with a PCR policy Evan Green
2022-05-06 16:08 ` [PATCH 00/10] Encrypted Hibernation Pavel Machek
2022-05-09 16:43 ` Evan Green
2022-05-17 16:06 ` Rafael J. Wysocki
2022-05-17 17:34 ` Evan Green [this message]
2022-06-16 15:42 ` Evan Green
2022-08-01 22:32 ` Evan Green
2022-08-02 18:36 ` Matthew Garrett
2022-08-04 0:59 ` Jarkko Sakkinen
2022-08-04 21:55 ` Evan Green
2022-08-06 18:21 ` Jarkko Sakkinen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAE=gft6V6RLc-d4AOuRUVU2u1jMGghDRSrFqiCqMCLxemui8Pw@mail.gmail.com' \
--to=evgreen@chromium.org \
--cc=axelj@axis.com \
--cc=corbet@lwn.net \
--cc=dhowells@redhat.com \
--cc=dlunev@google.com \
--cc=gwendal@chromium.org \
--cc=hao.wu@rubrik.com \
--cc=jarkko@kernel.org \
--cc=jejb@linux.ibm.com \
--cc=jgg@ziepe.ca \
--cc=jmorris@namei.org \
--cc=keyrings@vger.kernel.org \
--cc=len.brown@intel.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=matthewgarrett@google.com \
--cc=mgarrett@aurora.tech \
--cc=pavel@ucw.cz \
--cc=peterhuewe@gmx.de \
--cc=rafael@kernel.org \
--cc=rjw@rjwysocki.net \
--cc=serge@hallyn.com \
--cc=zohar@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).