From patchwork Mon Jul 13 16:48:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Bruno Meneguele X-Patchwork-Id: 11660725 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 58B5314DD for ; Mon, 13 Jul 2020 16:48:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 407C0207D4 for ; Mon, 13 Jul 2020 16:48:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cXV7tsHj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730325AbgGMQss (ORCPT ); Mon, 13 Jul 2020 12:48:48 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:43940 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730265AbgGMQss (ORCPT ); Mon, 13 Jul 2020 12:48:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594658927; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=84HXSEfmbt0+vn1F/xRQMsKwpXDD6K/wrYokP/216f8=; b=cXV7tsHjNOBWlKwvRD07BpixmAm1xZl/XWBLWo19CebdnsZEoZNXJiZitOOelxTJBIsdhu 2wVWDH34gpTXNNYl6bh5x6rcE0wEYefC0ochGaiQZTHkT7smmV6NVrREJZ6+gqLTGwdG5j tRS7rNgN73tjEa+R6FJzGKoLkQTyeLo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-422-taVAPnOMMCiMeU52nuZSZQ-1; Mon, 13 Jul 2020 12:48:45 -0400 X-MC-Unique: taVAPnOMMCiMeU52nuZSZQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3F831800597; Mon, 13 Jul 2020 16:48:42 +0000 (UTC) Received: from localhost (ovpn-116-10.gru2.redhat.com [10.97.116.10]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0F9791053B31; Mon, 13 Jul 2020 16:48:32 +0000 (UTC) From: Bruno Meneguele To: linux-kernel@vger.kernel.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-integrity@vger.kernel.org Cc: zohar@linux.ibm.com, erichte@linux.ibm.com, nayna@linux.ibm.com, stable@vger.kernel.org, Bruno Meneguele Subject: [PATCH v6] ima: move APPRAISE_BOOTPARAM dependency on ARCH_POLICY to runtime Date: Mon, 13 Jul 2020 13:48:30 -0300 Message-Id: <20200713164830.101165-1-bmeneg@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org The IMA_APPRAISE_BOOTPARAM config allows enabling different "ima_appraise=" modes - log, fix, enforce - at run time, but not when IMA architecture specific policies are enabled.  This prevents properly labeling the filesystem on systems where secure boot is supported, but not enabled on the platform.  Only when secure boot is actually enabled should these IMA appraise modes be disabled. This patch removes the compile time dependency and makes it a runtime decision, based on the secure boot state of that platform. Test results as follows: -> x86-64 with secure boot enabled [ 0.015637] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix [ 0.015668] ima: Secure boot enabled: ignoring ima_appraise=fix boot parameter option -> powerpc with secure boot disabled [ 0.000000] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix [ 0.000000] Secure boot mode disabled -> Running the system without secure boot and with both options set: CONFIG_IMA_APPRAISE_BOOTPARAM=y CONFIG_IMA_ARCH_POLICY=y Audit prompts "missing-hash" but still allow execution and, consequently, filesystem labeling: type=INTEGRITY_DATA msg=audit(07/09/2020 12:30:27.778:1691) : pid=4976 uid=root auid=root ses=2 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 op=appraise_data cause=missing-hash comm=bash name=/usr/bin/evmctl dev="dm-0" ino=493150 res=no Cc: stable@vger.kernel.org Fixes: d958083a8f64 ("x86/ima: define arch_get_ima_policy() for x86") Signed-off-by: Bruno Meneguele Reviewed-by: Nayna Jain Tested-by: Nayna Jain --- v6: - explictly print the bootparam being ignored to the user (Mimi) v5: - add pr_info() to inform user the ima_appraise= boot param is being ignored due to secure boot enabled (Nayna) - add some testing results to commit log v4: - instead of change arch_policy loading code, check secure boot state at "ima_appraise=" parameter handler (Mimi) v3: - extend secure boot arch checker to also consider trusted boot - enforce IMA appraisal when secure boot is effectively enabled (Nayna) - fix ima_appraise flag assignment by or'ing it (Mimi) v2: - pr_info() message prefix correction security/integrity/ima/Kconfig | 2 +- security/integrity/ima/ima_appraise.c | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index edde88dbe576..62dc11a5af01 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -232,7 +232,7 @@ config IMA_APPRAISE_REQUIRE_POLICY_SIGS config IMA_APPRAISE_BOOTPARAM bool "ima_appraise boot parameter" - depends on IMA_APPRAISE && !IMA_ARCH_POLICY + depends on IMA_APPRAISE default y help This option enables the different "ima_appraise=" modes diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index a9649b04b9f1..28a59508c6bd 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -19,6 +19,12 @@ static int __init default_appraise_setup(char *str) { #ifdef CONFIG_IMA_APPRAISE_BOOTPARAM + if (arch_ima_get_secureboot()) { + pr_info("Secure boot enabled: ignoring ima_appraise=%s boot parameter option", + str); + return 1; + } + if (strncmp(str, "off", 3) == 0) ima_appraise = 0; else if (strncmp(str, "log", 3) == 0)