From mboxrd@z Thu Jan 1 00:00:00 1970 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=ham 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 F3169C433E1 for ; Mon, 17 Aug 2020 15:51:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8BE020657 for ; Mon, 17 Aug 2020 15:51:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597679467; bh=I0mBP7wTCEKkZIwHjCDfXcQWyWEOqJFbo3CJkQzU6tM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SKX+HncEKxKHVzuUO0vka/RXtBsf59iv7gpg8aydj/ebEB3FxXWuDL8AV3EyjEHpR RYAUsPlsGO/zJsbJ3dMSQV1api0tcEHTyNHhWImvcqZx0nbUi2ed7qj4aMRn2ib2ZF jD8cQredOxtaTovbk6QSmg5BnSuU+bVOjImkvirg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730899AbgHQPux (ORCPT ); Mon, 17 Aug 2020 11:50:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:35234 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730887AbgHQPum (ORCPT ); Mon, 17 Aug 2020 11:50:42 -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 830682054F; Mon, 17 Aug 2020 15:50:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597679439; bh=I0mBP7wTCEKkZIwHjCDfXcQWyWEOqJFbo3CJkQzU6tM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=imcMm0pwqITbvdtKJKylTlRjhOHV5MvRSBZ0eKZjj/sfENNLV6zqhg9/GgkyirO/p OC0NTV3eHw/Pe10eABncVzC6SFrivxV0pKAcim4WSTNr6a9qjI2EbNMkMtTWSWdSpc Z+mz27UFUZeuDtzidov8Ivq2jftuartCbhyNQjUY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tyler Hicks , Mimi Zohar , Lakshmi Ramasubramanian , Sasha Levin Subject: [PATCH 5.7 211/393] ima: Fail rule parsing when the KEXEC_CMDLINE hook is combined with an invalid cond Date: Mon, 17 Aug 2020 17:14:21 +0200 Message-Id: <20200817143829.860873227@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143819.579311991@linuxfoundation.org> References: <20200817143819.579311991@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tyler Hicks [ Upstream commit db2045f5892a9db7354442bf77f9b03b50ff9ee1 ] The KEXEC_CMDLINE hook function only supports the pcr conditional. Make this clear at policy load so that IMA policy authors don't assume that other conditionals are supported. Since KEXEC_CMDLINE's inception, ima_match_rules() has always returned true on any loaded KEXEC_CMDLINE rule without any consideration for other conditionals present in the rule. Make it clear that pcr is the only supported KEXEC_CMDLINE conditional by returning an error during policy load. An example of why this is a problem can be explained with the following rule: dont_measure func=KEXEC_CMDLINE obj_type=foo_t An IMA policy author would have assumed that rule is valid because the parser accepted it but the result was that measurements for all KEXEC_CMDLINE operations would be disabled. Fixes: b0935123a183 ("IMA: Define a new hook to measure the kexec boot command line arguments") Signed-off-by: Tyler Hicks Reviewed-by: Mimi Zohar Reviewed-by: Lakshmi Ramasubramanian Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin --- security/integrity/ima/ima_policy.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index a3d72342408ad..a77e0b34e72f7 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -343,6 +343,17 @@ static int ima_lsm_update_rule(struct ima_rule_entry *entry) return 0; } +static bool ima_rule_contains_lsm_cond(struct ima_rule_entry *entry) +{ + int i; + + for (i = 0; i < MAX_LSM_RULES; i++) + if (entry->lsm[i].args_p) + return true; + + return false; +} + /* * The LSM policy can be reloaded, leaving the IMA LSM based rules referring * to the old, stale LSM policy. Update the IMA LSM based rules to reflect @@ -998,6 +1009,16 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) /* Validation of these hook functions is in ima_parse_rule() */ break; case KEXEC_CMDLINE: + if (entry->action & ~(MEASURE | DONT_MEASURE)) + return false; + + if (entry->flags & ~(IMA_FUNC | IMA_PCR)) + return false; + + if (ima_rule_contains_lsm_cond(entry)) + return false; + + break; case KEY_CHECK: if (entry->action & ~(MEASURE | DONT_MEASURE)) return false; -- 2.25.1