From patchwork Mon Aug 17 15:13:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 265970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF27EC433DF for ; Mon, 17 Aug 2020 19:35:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEF0A2065D for ; Mon, 17 Aug 2020 19:35:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597692920; bh=cbANANyU/YMVkf+WiiSd6M9TsPsYv2l6Y4+7w6+2p+Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WJemkf3pdQFSuQvgkRPMRyHKQFw1+hfDK5i1+VrsCfIvyu5cT/tLs/ymvNiSrI8w7 v5sH4Nsch+2eY8EOJWrVikpW7NcO90LmKqiSXIkF4eKnaIVkRemSgTHDoTZzMPggku zXxgTek0uHSkJ6WW4/uhVPYf3MggOniRCMJQ5aLo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730101AbgHQP3c (ORCPT ); Mon, 17 Aug 2020 11:29:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:48200 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730096AbgHQP3b (ORCPT ); Mon, 17 Aug 2020 11:29:31 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9E14523110; Mon, 17 Aug 2020 15:29:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597678171; bh=cbANANyU/YMVkf+WiiSd6M9TsPsYv2l6Y4+7w6+2p+Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HgxCLR/iRBPiinGKgXqv0PFC28BthKEfwzZRCqMU1w3RhMj8DA4MMt1mFyfcg002w X+nxcw8sbo+UnoOkdeD7ZubmHcujGQEoCcN1YBs/b8UVFKOmli6XpWERFwhgeWbZ74 UfhaeYJAEZsF75FMmmPDF3StW7x9RX96LAmnbNVU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tyler Hicks , Mimi Zohar , Sasha Levin Subject: [PATCH 5.8 242/464] ima: Fail rule parsing when buffer hook functions have an invalid action Date: Mon, 17 Aug 2020 17:13:15 +0200 Message-Id: <20200817143845.388266628@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143833.737102804@linuxfoundation.org> References: <20200817143833.737102804@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tyler Hicks [ Upstream commit 712183437ebebc89cd086ef96cf9a521fd97fd09 ] Buffer based hook functions, such as KEXEC_CMDLINE and KEY_CHECK, can only measure. The process_buffer_measurement() function quietly ignores all actions except measure so make this behavior clear at the time of policy load. The parsing of the keyrings conditional had a check to ensure that it was only specified with measure actions but the check should be on the hook function and not the keyrings conditional since "appraise func=KEY_CHECK" is not a valid rule. Fixes: b0935123a183 ("IMA: Define a new hook to measure the kexec boot command line arguments") Fixes: 5808611cccb2 ("IMA: Add KEY_CHECK func to measure keys") Signed-off-by: Tyler Hicks Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin --- security/integrity/ima/ima_policy.c | 40 +++++++++++++++++++++++++++-- 1 file changed, 38 insertions(+), 2 deletions(-) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 18271920d315d..a3d72342408ad 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -973,6 +973,43 @@ static void check_template_modsig(const struct ima_template_desc *template) #undef MSG } +static bool ima_validate_rule(struct ima_rule_entry *entry) +{ + /* Ensure that the action is set */ + if (entry->action == UNKNOWN) + return false; + + /* + * Ensure that the hook function is compatible with the other + * components of the rule + */ + switch (entry->func) { + case NONE: + case FILE_CHECK: + case MMAP_CHECK: + case BPRM_CHECK: + case CREDS_CHECK: + case POST_SETATTR: + case MODULE_CHECK: + case FIRMWARE_CHECK: + case KEXEC_KERNEL_CHECK: + case KEXEC_INITRAMFS_CHECK: + case POLICY_CHECK: + /* Validation of these hook functions is in ima_parse_rule() */ + break; + case KEXEC_CMDLINE: + case KEY_CHECK: + if (entry->action & ~(MEASURE | DONT_MEASURE)) + return false; + + break; + default: + return false; + } + + return true; +} + static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) { struct audit_buffer *ab; @@ -1150,7 +1187,6 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) keyrings_len = strlen(args[0].from) + 1; if ((entry->keyrings) || - (entry->action != MEASURE) || (entry->func != KEY_CHECK) || (keyrings_len < 2)) { result = -EINVAL; @@ -1356,7 +1392,7 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) break; } } - if (!result && (entry->action == UNKNOWN)) + if (!result && !ima_validate_rule(entry)) result = -EINVAL; else if (entry->action == APPRAISE) temp_ima_appraise |= ima_appraise_flag(entry->func);