From: Mimi Zohar <zohar@linux.ibm.com>
To: Pavel Machek <pavel@ucw.cz>,
Tushar Sugandhi <tusharsu@linux.microsoft.com>
Cc: stephen.smalley.work@gmail.com, casey@schaufler-ca.com,
agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com,
paul@paul-moore.com, tyhicks@linux.microsoft.com,
sashal@kernel.org, jmorris@namei.org, nramas@linux.microsoft.com,
linux-integrity@vger.kernel.org, selinux@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, dm-devel@redhat.com
Subject: Re: [PATCH v6 0/8] IMA: support for measuring kernel integrity critical data
Date: Mon, 23 Nov 2020 08:41:35 -0500 [thread overview]
Message-ID: <d82ad1cac36e948c904300548c64244c145589ee.camel@linux.ibm.com> (raw)
In-Reply-To: <20201122210031.GA26756@amd>
Hi Pavel,
On Sun, 2020-11-22 at 22:00 +0100, Pavel Machek wrote:
> Hi!
>
> > >How is it supposed to be useful?
> > >
> > >I'm pretty sure there are critical data that are not measured by
> > >proposed module... and that are written under normal circumstances.
> > >
> > The goal of this series is to introduce the IMA hook
> > measure_critical_data() and the necessary policies to use it; and
> > illustrate that use with one example (SELinux). It is not scalable to
> > identify and update all the critical data sources to use the proposed
> > module at once.
> >
> > A piecemeal approach to add more critical data measurement in subsequent
> > patches would be easy to implement and review.
>
> Basically every other data structure in kernel is "critical" by your
> definition, and you can't really measure them all; some of them change
> rather often. Going piecemeal does not really help here.
Agreed, measuring data structures that change is not really applicable.
However, measuring data structures that once initialized don't change,
does make sense (similar concept to __ro_after_init). The attestation
server doesn't need to know anything about the measurement, other than
more than a single measurement is indicative of a problem.
Mimi
> Example of critical data structure: page table entries for process I
> own.
next prev parent reply other threads:[~2020-11-23 13:41 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-19 23:26 [PATCH v6 0/8] IMA: support for measuring kernel integrity critical data Tushar Sugandhi
2020-11-19 23:26 ` [PATCH v6 1/8] IMA: generalize keyring specific measurement constructs Tushar Sugandhi
2020-11-19 23:26 ` [PATCH v6 2/8] IMA: add support to measure buffer data hash Tushar Sugandhi
2020-11-19 23:26 ` [PATCH v6 3/8] IMA: define a hook to measure kernel integrity critical data Tushar Sugandhi
2020-11-19 23:26 ` [PATCH v6 4/8] IMA: add policy rule to measure " Tushar Sugandhi
2020-11-19 23:26 ` [PATCH v6 5/8] IMA: extend policy to add data sources as a critical data measurement constraint Tushar Sugandhi
2020-11-19 23:26 ` [PATCH v6 6/8] IMA: add support to critical data hook to limit data sources for measurement Tushar Sugandhi
2020-11-19 23:26 ` [PATCH v6 7/8] IMA: add a built-in policy rule for critical data measurement Tushar Sugandhi
2020-11-20 14:30 ` Mimi Zohar
2020-11-20 23:33 ` Lakshmi Ramasubramanian
2020-11-19 23:26 ` [PATCH v6 8/8] selinux: measure state and hash of the policy using IMA Tushar Sugandhi
2020-11-20 15:49 ` Mimi Zohar
2020-11-20 23:40 ` Lakshmi Ramasubramanian
2020-11-21 2:05 ` James Morris
2020-11-23 19:37 ` Tushar Sugandhi
2020-11-20 12:46 ` [PATCH v6 0/8] IMA: support for measuring kernel integrity critical data Pavel Machek
2020-11-22 20:53 ` Tushar Sugandhi
2020-11-22 21:00 ` Pavel Machek
2020-11-23 13:41 ` Mimi Zohar [this message]
2020-11-23 17:18 ` Pavel Machek
2020-11-23 19:49 ` Mimi Zohar
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