From: Mimi Zohar <zohar@linux.ibm.com>
To: Thiago Jung Bauermann <bauerman@linux.ibm.com>,
linux-integrity@vger.kernel.org
Cc: linux-security-module@vger.kernel.org, keyrings@vger.kernel.org,
linux-crypto@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
David Howells <dhowells@redhat.com>,
David Woodhouse <dwmw2@infradead.org>,
Jessica Yu <jeyu@kernel.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>,
Jonathan Corbet <corbet@lwn.net>,
"AKASHI, Takahiro" <takahiro.akashi@linaro.org>
Subject: Re: [PATCH v10 12/12] ima: Store the measurement again when appraising a modsig
Date: Tue, 28 May 2019 10:09:20 -0400 [thread overview]
Message-ID: <1559052560.4090.14.camel@linux.ibm.com> (raw)
In-Reply-To: <20190418035120.2354-13-bauerman@linux.ibm.com>
Hi Thiago,
On Thu, 2019-04-18 at 00:51 -0300, Thiago Jung Bauermann wrote:
> If the IMA template contains the "modsig" or "d-modsig" field, then the
> modsig should be added to the measurement list when the file is appraised.
>
> And that is what normally happens, but if a measurement rule caused a file
> containing a modsig to be measured before a different rule causes it to be
> appraised, the resulting measurement entry will not contain the modsig
> because it is only fetched during appraisal. When the appraisal rule
> triggers, it won't store a new measurement containing the modsig because
> the file was already measured.
>
> We need to detect that situation and store an additional measurement with
> the modsig. This is done by adding an IMA_MEASURE action flag if we read a
> modsig and the IMA template contains a modsig field.
With the new per policy rule "template" support being added, this
patch needs to be modified so that the per policy "template" format is
checked. ima_template_has_modsig() should be called with the
template_desc being used.
thanks,
Mimi
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 8e6475854351..f91ed4189f98 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -282,9 +282,17 @@ static int process_measurement(struct file *file, const struct cred *cred,
> /* read 'security.ima' */
> xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
>
> - /* Read the appended modsig if allowed by the policy. */
> - if (iint->flags & IMA_MODSIG_ALLOWED)
> - ima_read_modsig(func, buf, size, &modsig);
> + /*
> + * Read the appended modsig, if allowed by the policy, and allow
> + * an additional measurement list entry, if needed, based on the
> + * template format.
> + */
> + if (iint->flags & IMA_MODSIG_ALLOWED) {
> + rc = ima_read_modsig(func, buf, size, &modsig);
> +
> + if (!rc && ima_template_has_modsig())
> + action |= IMA_MEASURE;
> + }
>
next prev parent reply other threads:[~2019-05-28 14:10 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-18 3:51 [PATCH v10 00/12] Appended signatures support for IMA appraisal Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 01/12] MODSIGN: Export module signature definitions Thiago Jung Bauermann
2019-05-09 15:42 ` Mimi Zohar
2019-05-28 19:03 ` Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 02/12] PKCS#7: Refactor verify_pkcs7_signature() Thiago Jung Bauermann
2019-05-09 15:42 ` Mimi Zohar
2019-04-18 3:51 ` [PATCH v10 03/12] PKCS#7: Introduce pkcs7_get_digest() Thiago Jung Bauermann
2019-05-09 15:42 ` Mimi Zohar
2019-04-18 3:51 ` [PATCH v10 04/12] integrity: Introduce struct evm_xattr Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 05/12] integrity: Select CONFIG_KEYS instead of depending on it Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 06/12] ima: Use designated initializers for struct ima_event_data Thiago Jung Bauermann
2019-05-09 15:46 ` Mimi Zohar
2019-04-18 3:51 ` [PATCH v10 07/12] ima: Add modsig appraise_type option for module-style appended signatures Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 08/12] ima: Factor xattr_verify() out of ima_appraise_measurement() Thiago Jung Bauermann
2019-05-09 15:53 ` Mimi Zohar
2019-04-18 3:51 ` [PATCH v10 09/12] ima: Implement support for module-style appended signatures Thiago Jung Bauermann
2019-05-09 23:01 ` Mimi Zohar
2019-05-28 19:23 ` Thiago Jung Bauermann
2019-05-28 20:06 ` Mimi Zohar
2019-05-14 12:09 ` Mimi Zohar
2019-05-28 19:27 ` Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 10/12] ima: Collect modsig Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 11/12] ima: Define ima-modsig template Thiago Jung Bauermann
2019-05-09 23:01 ` Mimi Zohar
2019-05-28 19:09 ` Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 12/12] ima: Store the measurement again when appraising a modsig Thiago Jung Bauermann
2019-05-28 14:09 ` Mimi Zohar [this message]
2019-05-28 19:14 ` Thiago Jung Bauermann
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