linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mimi Zohar <zohar@linux.ibm.com>
To: Eric Snowberg <eric.snowberg@oracle.com>
Cc: Nayna <nayna@linux.vnet.ibm.com>,
	dmitry.kasatkin@gmail.com, jmorris@namei.org, serge@hallyn.com,
	dhowells@redhat.com, geert@linux-m68k.org,
	gregkh@linuxfoundation.org, nayna@linux.ibm.com,
	tglx@linutronix.de, bauerman@linux.ibm.com, mpe@ellerman.id.au,
	linux-integrity@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 0/2] ima: uncompressed module appraisal support
Date: Fri, 07 Feb 2020 13:54:32 -0500	[thread overview]
Message-ID: <1581101672.5585.628.camel@linux.ibm.com> (raw)
In-Reply-To: <992E95D5-D4B9-4913-A36F-BB47631DFE0A@oracle.com>

On Fri, 2020-02-07 at 11:45 -0700, Eric Snowberg wrote:
> 
> > On Feb 7, 2020, at 11:28 AM, Mimi Zohar <zohar@linux.ibm.com> wrote:
> > 
> > On Fri, 2020-02-07 at 10:49 -0700, Eric Snowberg wrote:
> >> 
> >>> On Feb 7, 2020, at 10:40 AM, Mimi Zohar <zohar@linux.ibm.com> wrote:
> >>> 
> >>>> $ insmod ./foo.ko
> >>>> insmod: ERROR: could not insert module ./foo.ko: Permission denied
> >>>> 
> >>>> last entry from audit log:
> >>>> type=INTEGRITY_DATA msg=audit(1581089373.076:83): pid=2874 uid=0
> >>>> auid=0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-
> >>>> s0:c0.c1023 op=appraise_data cause=invalid-signature comm="insmod"
> >>>> name="/root/keys/modules/foo.ko" dev="dm-0" ino=10918365
> >>>> res=0^]UID="root" AUID=“root"
> >>>> 
> >>>> This is because modsig_verify() will be called from within
> >>>> ima_appraise_measurement(), 
> >>>> since try_modsig is true.  Then modsig_verify() will return
> >>>> INTEGRITY_FAIL.
> >>> 
> >>> Why is it an "invalid signature"?  For that you need to look at the
> >>> kernel messages.  Most likely it can't find the public key on the .ima
> >>> keyring to verify the signature.
> >> 
> >> It is invalid because the module has not been ima signed. 
> > 
> > With the IMA policy rule "appraise func=MODULE_CHECK
> > appraise_type=imasig|modsig", IMA first tries to verify the IMA
> > signature stored as an xattr and on failure then attempts to verify
> > the appended signatures.
> > 
> > The audit message above indicates that there was a signature, but the
> > signature validation failed.
> > 
> 
> I do have  CONFIG_IMA_APPRAISE_MODSIG enabled.  I believe the audit message above 
> is coming from modsig_verify in security/integrity/ima/ima_appraise.c.

Right, and it's calling:

	rc = integrity_modsig_verify(INTEGRITY_KEYRING_IMA, modsig);

It's failing because it is trying to find the public key on the .ima
keyring.  Make sure that the public needed to validate the kernel
module is on the IMA keyring (eg. keyctl show %keyring:.ima).

Mimi


  reply	other threads:[~2020-02-07 18:54 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-06 16:42 Eric Snowberg
2020-02-06 16:42 ` [RFC PATCH 1/2] ima: Implement support for uncompressed module appended signatures Eric Snowberg
2020-02-06 17:07   ` Lakshmi Ramasubramanian
2020-02-06 17:30     ` Eric Snowberg
2020-02-06 18:05   ` Mimi Zohar
2020-02-06 19:01     ` Eric Snowberg
2020-02-06 19:10       ` Mimi Zohar
2020-02-06 16:42 ` [RFC PATCH 2/2] ima: Change default secure_boot policy to include " Eric Snowberg
2020-02-06 20:22 ` [RFC PATCH 0/2] ima: uncompressed module appraisal support Nayna
2020-02-06 21:40   ` Eric Snowberg
2020-02-07 14:51     ` Mimi Zohar
2020-02-07 16:57       ` Eric Snowberg
2020-02-07 17:40         ` Mimi Zohar
2020-02-07 17:49           ` Eric Snowberg
2020-02-07 18:28             ` Mimi Zohar
2020-02-07 18:45               ` Eric Snowberg
2020-02-07 18:54                 ` Mimi Zohar [this message]
2020-02-07 21:38                   ` Eric Snowberg
2020-02-08 23:43                     ` Mimi Zohar
2020-02-10 16:34                       ` Eric Snowberg
2020-02-10 17:09                         ` Mimi Zohar
2020-02-10 19:24                           ` Eric Snowberg
2020-02-10 20:33                             ` Mimi Zohar
2020-02-11 17:33                               ` Eric Snowberg
2020-02-12 14:04                                 ` Nayna
2020-02-13 15:32                                   ` Eric Snowberg

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=1581101672.5585.628.camel@linux.ibm.com \
    --to=zohar@linux.ibm.com \
    --cc=bauerman@linux.ibm.com \
    --cc=dhowells@redhat.com \
    --cc=dmitry.kasatkin@gmail.com \
    --cc=eric.snowberg@oracle.com \
    --cc=geert@linux-m68k.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=jmorris@namei.org \
    --cc=linux-integrity@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=mpe@ellerman.id.au \
    --cc=nayna@linux.ibm.com \
    --cc=nayna@linux.vnet.ibm.com \
    --cc=serge@hallyn.com \
    --cc=tglx@linutronix.de \
    --subject='Re: [RFC PATCH 0/2] ima: uncompressed module appraisal support' \
    /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

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).