From: Evan Green <evgreen@chromium.org>
To: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Matthew Garrett <mgarrett@aurora.tech>,
Ken Goldman <kgold@linux.ibm.com>,
LKML <linux-kernel@vger.kernel.org>,
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>,
Linux PM <linux-pm@vger.kernel.org>,
Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
"Rafael J. Wysocki" <rafael@kernel.org>
Subject: Re: TPM: hibernate with IMA PCR 10
Date: Wed, 7 Sep 2022 13:47:47 -0700 [thread overview]
Message-ID: <CAE=gft68it0VtFfddCiSQYfz2+Fmoc+6ZK-ounDrjuRJ8nsOLw@mail.gmail.com> (raw)
In-Reply-To: <Yw7L+X2cHf9qprxl@kernel.org>
On Tue, Aug 30, 2022 at 7:48 PM Jarkko Sakkinen <jarkko@kernel.org> wrote:
>
> On Mon, Aug 29, 2022 at 02:51:50PM -0700, Matthew Garrett wrote:
> > On Mon, Aug 29, 2022 at 2:45 PM Ken Goldman <kgold@linux.ibm.com> wrote:
> > >
> > > On 5/4/2022 7:20 PM, Evan Green wrote:
> > > > Enabling the kernel to be able to do encryption and integrity checks on
> > > > the hibernate image prevents a malicious userspace from escalating to
> > > > kernel execution via hibernation resume. [snip]
> > >
> > > I have a related question.
> > >
> > > When a TPM powers up from hibernation, PCR 10 is reset. When a
> > > hibernate image is restored:
> > >
> > > 1. Is there a design for how PCR 10 is restored?
> >
> > I don't see anything that does that at present.
> >
> > > 2. How are /sys/kernel/security/ima/[pseudofiles] saved and
> > > restored?
> >
> > They're part of the running kernel state, so should re-appear without
> > any special casing. However, in the absence of anything repopulating
> > PCR 10, they'll no longer match the in-TPM value.
>
> This feature could still be supported, if IMA is disabled
> in the kernel configuration, which I see a non-issue as
> long as config flag checks are there.
Right, from what I understand about IMA, the TPM's PCR getting out of
sync with the in-kernel measurement list across a hibernate (because
TPM is reset) or kexec() (because in-memory list gets reset) is
already a problem. This series doesn't really address that, in that it
doesn't really make that situation better or worse.
-Evan
next prev parent reply other threads:[~2022-09-07 20:48 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 [this message]
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
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
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