From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gX92U-0002Rl-3v for kexec@lists.infradead.org; Wed, 12 Dec 2018 18:15:19 +0000 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wBCIDc8u051241 for ; Wed, 12 Dec 2018 13:15:06 -0500 Received: from e34.co.us.ibm.com (e34.co.us.ibm.com [32.97.110.152]) by mx0a-001b2d01.pphosted.com with ESMTP id 2pb793gge9-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 12 Dec 2018 13:15:05 -0500 Received: from localhost by e34.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 12 Dec 2018 18:15:05 -0000 References: <20181208202705.18673-1-nayna@linux.ibm.com> <20181208202705.18673-8-nayna@linux.ibm.com> From: Thiago Jung Bauermann Subject: Re: [PATCH v2 7/7] ima: Support platform keyring for kernel appraisal In-reply-to: <20181208202705.18673-8-nayna@linux.ibm.com> Date: Wed, 12 Dec 2018 16:14:47 -0200 MIME-Version: 1.0 Message-Id: <8736r2fw88.fsf@morokweng.localdomain> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Nayna Jain Cc: linux-efi@vger.kernel.org, mpe@ellerman.id.au, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, zohar@linux.ibm.com, dhowells@redhat.com, seth.forshee@canonical.com, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, ebiederm@xmission.com, jforbes@redhat.com, linux-integrity@vger.kernel.org, vgoyal@redhat.com Hello, Nayna Jain writes: > On secure boot enabled systems, the bootloader verifies the kernel > image and possibly the initramfs signatures based on a set of keys. A > soft reboot(kexec) of the system, with the same kernel image and > initramfs, requires access to the original keys to verify the > signatures. > > This patch allows IMA-appraisal access to those original keys, now > loaded on the platform keyring, needed for verifying the kernel image > and initramfs signatures. > > Signed-off-by: Nayna Jain > Reviewed-by: Mimi Zohar > Acked-by: Serge Hallyn > - replace 'rc' with 'xattr_len' when calling integrity_digsig_verify() > with INTEGRITY_KEYRING_IMA for readability > Suggested-by: Serge Hallyn > --- > Changelog: > > v2: > - replace 'rc' with 'xattr_len' when calling integrity_digsig_verify() > with INTEGRITY_KEYRING_IMA for readability > > security/integrity/ima/ima_appraise.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c > index deec1804a00a..e8f520450895 100644 > --- a/security/integrity/ima/ima_appraise.c > +++ b/security/integrity/ima/ima_appraise.c > @@ -289,12 +289,21 @@ int ima_appraise_measurement(enum ima_hooks func, > case EVM_IMA_XATTR_DIGSIG: > set_bit(IMA_DIGSIG, &iint->atomic_flags); > rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA, > - (const char *)xattr_value, rc, > + (const char *)xattr_value, > + xattr_len, > iint->ima_hash->digest, > iint->ima_hash->length); > if (rc == -EOPNOTSUPP) { > status = INTEGRITY_UNKNOWN; > - } else if (rc) { > + break; > + } > + if (rc && func == KEXEC_KERNEL_CHECK) > + rc = integrity_digsig_verify(INTEGRITY_KEYRING_PLATFORM, > + (const char *)xattr_value, > + xattr_len, > + iint->ima_hash->digest, > + iint->ima_hash->length); If CONFIG_INTEGRITY_PLATFORM_KEYRING=n the second call to integrity_digsig_verify() above will always fail, and the audit message of failed signature verifications for KEXEC_KERNEL will always log the same rc value, which is whatever request_key() returns when asked to look for an inexistent keyring. Here is a patch which only performs the second try if the platform keyring is enabled. >From d5fb94ab9eb13f6294f8dc44d1344cb85dfa41b8 Mon Sep 17 00:00:00 2001 From: Thiago Jung Bauermann Date: Wed, 12 Dec 2018 16:02:09 -0200 Subject: [PATCH] ima: Only use the platform keyring if it's enabled Signed-off-by: Thiago Jung Bauermann --- security/integrity/ima/ima_appraise.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index e8f520450895..f6ac405daabb 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -297,7 +297,8 @@ int ima_appraise_measurement(enum ima_hooks func, status = INTEGRITY_UNKNOWN; break; } - if (rc && func == KEXEC_KERNEL_CHECK) + if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc && + func == KEXEC_KERNEL_CHECK) rc = integrity_digsig_verify(INTEGRITY_KEYRING_PLATFORM, (const char *)xattr_value, xattr_len, _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec