From: Kees Cook <keescook@chromium.org>
To: "Mickaël Salaün" <mic@digikod.net>
Cc: Mimi Zohar <zohar@linux.ibm.com>,
Paul Moore <paul@paul-moore.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
linux-security-module@vger.kernel.org,
linux-integrity@vger.kernel.org, KP Singh <kpsingh@kernel.org>,
Casey Schaufler <casey@schaufler-ca.com>,
John Johansen <john.johansen@canonical.com>,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH 1/9] integrity: Prepare for having "ima" and "evm" available in "integrity" LSM
Date: Wed, 19 Oct 2022 11:33:38 -0700 [thread overview]
Message-ID: <202210191129.BFBF8035@keescook> (raw)
In-Reply-To: <0d2b9d34-2eda-8aa6-d596-eb1899645192@digikod.net>
On Mon, Oct 17, 2022 at 11:26:44AM +0200, Mickaël Salaün wrote:
>
> On 14/10/2022 19:59, Kees Cook wrote:
> > On Fri, Oct 14, 2022 at 04:40:01PM +0200, Mickaël Salaün wrote:
> > > This is not backward compatible
> >
> > Why? Nothing will be running LSM hooks until init finishes, at which
> > point the integrity inode cache will be allocated. And ima and evm don't
> > start up until lateinit.
> >
> > > , but can easily be fixed thanks to
> > > DEFINE_LSM().order
> >
> > That forces the LSM to be enabled, which may not be desired?
>
> This is not backward compatible because currently IMA is enabled
> independently of the "lsm=" cmdline, which means that for all installed
> systems using IMA and also with a custom "lsm=" cmdline, updating the kernel
> with this patch will (silently) disable IMA. Using ".order =
> LSM_ORDER_FIRST," should keep this behavior.
This isn't true. If "integrity" is removed from the lsm= line today, IMA
will immediately panic:
process_measurement():
integrity_inode_get():
if (!iint_cache)
panic("%s: lsm=integrity required.\n", __func__);
and before v5.12 (where the panic was added), it would immediately NULL
deref. (And it took 3 years to even notice.)
--
Kees Cook
next prev parent reply other threads:[~2022-10-19 18:33 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-13 22:36 [PATCH 0/9] integrity: Move hooks into LSM Kees Cook
2022-10-13 22:36 ` [PATCH 1/9] integrity: Prepare for having "ima" and "evm" available in "integrity" LSM Kees Cook
2022-10-14 14:40 ` Mickaël Salaün
2022-10-14 17:59 ` Kees Cook
2022-10-17 9:26 ` Mickaël Salaün
2022-10-17 18:11 ` Kees Cook
2022-10-19 18:33 ` Kees Cook [this message]
2022-10-19 19:13 ` Mimi Zohar
2022-10-19 22:37 ` Kees Cook
2022-10-19 14:34 ` Mimi Zohar
2022-10-19 18:28 ` Kees Cook
2022-10-13 22:36 ` [PATCH 2/9] security: Move trivial IMA hooks into LSM Kees Cook
2022-10-19 14:34 ` Mimi Zohar
2022-10-19 18:59 ` Kees Cook
2022-10-19 20:45 ` Mimi Zohar
2022-10-19 23:41 ` Kees Cook
2022-10-20 12:17 ` Mimi Zohar
2022-10-21 14:53 ` Dr. Greg
2022-10-21 15:09 ` Casey Schaufler
2022-10-13 22:36 ` [PATCH 3/9] ima: Move xattr " Kees Cook
2022-10-18 15:07 ` Christian Brauner
2022-10-19 13:24 ` Mimi Zohar
2022-10-13 22:36 ` [PATCH 4/9] ima: Move ima_file_free() " Kees Cook
2022-10-18 15:02 ` Christian Brauner
2022-10-18 15:32 ` Roberto Sassu
2022-10-18 18:29 ` Kees Cook
2022-10-19 6:55 ` Roberto Sassu
2022-10-20 15:47 ` Paul Moore
2022-10-13 22:36 ` [PATCH 5/9] LSM: Introduce inode_post_setattr hook Kees Cook
2022-10-18 14:50 ` Christian Brauner
2022-10-13 22:36 ` [PATCH 6/9] fs: Introduce file_to_perms() helper Kees Cook
2022-10-18 14:10 ` Christian Brauner
2022-10-18 18:25 ` Kees Cook
2022-10-20 17:29 ` Casey Schaufler
2022-10-20 23:04 ` Kees Cook
2022-10-13 22:36 ` [PATCH 7/9] ima: Move ima_file_check() into LSM Kees Cook
2022-10-13 22:36 ` [PATCH 8/9] integrity: Move trivial hooks " Kees Cook
2022-10-13 22:36 ` [PATCH 9/9] integrity: Move integrity_inode_get() out of global header Kees Cook
2022-10-13 22:47 ` [PATCH 0/9] integrity: Move hooks into LSM Paul Moore
2022-10-14 1:16 ` Mimi Zohar
2022-10-18 15:31 ` Mickaël Salaün
2022-10-18 15:38 ` Roberto Sassu
2022-10-18 18:31 ` Kees Cook
2022-10-20 17:36 ` Casey Schaufler
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=202210191129.BFBF8035@keescook \
--to=keescook@chromium.org \
--cc=casey@schaufler-ca.com \
--cc=dmitry.kasatkin@gmail.com \
--cc=jmorris@namei.org \
--cc=john.johansen@canonical.com \
--cc=kpsingh@kernel.org \
--cc=linux-hardening@vger.kernel.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mic@digikod.net \
--cc=paul@paul-moore.com \
--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).