From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-6.4 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id E594E7DE7B for ; Tue, 25 Sep 2018 00:25:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728337AbeIYGaM (ORCPT ); Tue, 25 Sep 2018 02:30:12 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:39141 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728195AbeIYGaK (ORCPT ); Tue, 25 Sep 2018 02:30:10 -0400 Received: by mail-pf1-f196.google.com with SMTP id j8-v6so9926230pff.6 for ; Mon, 24 Sep 2018 17:25:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=na71TelZGQ6m9GWmFesTEQd4UFPGStcPcyELJo/B8RM=; b=WT0YX7zWHH6WAFUpHrLCf6WlHBYsAnIO+a8HgEj8X2cHErLyMHE4+4lURbnqC9RSWP OAI/QXRK7mPFoG6493qlcbXboTjzJt9RnSjNs6ynisvoaqJDem5XEBsJFacRmRblesy5 zO8Y4O737dUtgCyCSBjo26tzCLDAdhdaVZOI4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=na71TelZGQ6m9GWmFesTEQd4UFPGStcPcyELJo/B8RM=; b=AaxfnrOjSnVlyV8Xch/2KgR+Vmr8a8zWG6XuFcTVoJ0FtbG4OnuLdg8Fvo/6PnW9z4 sLQFgu4orvBWWbr5JlApwCOrSYyUxADtuRsQyc98Vm+lxeufr/gSk9AwrCT5poDVxFQQ bElA8OrCFU7t5uf1OVriZ/zUqQjyDHLPH2UkEhzUt7xrmYEYm5JYwLIdWuTwn30Rgp0O ZPxtFeR1DBiEYF6tqYc/53/FcmL4fYdKukRbJD8i5FRK1q+BEd17lcELzHiVa7Cky5wC eAhaJ0quRsKM/mX31bJs+cjb4S3w0SSi26ZX3hSv66mKECkmhAW8tpPTBH8/KM9dywwe R/AQ== X-Gm-Message-State: ABuFfoiywNEcMLeVqbFBov7tO4BDZMWcBVyId00tQJiUhDnAbtlJuSxI dK5u7XYP/4SyZCC+oxtsUgl6GQ== X-Google-Smtp-Source: ACcGV63fiF8Usp5VDSHevpjSdzhvKONFzj5aTYfHcBlazhkjuEJWBw3JJudQ4OVRL0TAURsxjxz1Aw== X-Received: by 2002:a65:608b:: with SMTP id t11-v6mr936718pgu.259.1537835121914; Mon, 24 Sep 2018 17:25:21 -0700 (PDT) Received: from www.outflux.net (173-164-112-133-Oregon.hfc.comcastbusiness.net. [173.164.112.133]) by smtp.gmail.com with ESMTPSA id v190-v6sm547521pgb.16.2018.09.24.17.25.17 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 24 Sep 2018 17:25:20 -0700 (PDT) From: Kees Cook To: James Morris Cc: Kees Cook , Casey Schaufler , John Johansen , Tetsuo Handa , Paul Moore , Stephen Smalley , "Schaufler, Casey" , LSM , Jonathan Corbet , linux-doc@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH security-next v3 20/29] LSM: Refactor "security=" in terms of enable/disable Date: Mon, 24 Sep 2018 17:18:23 -0700 Message-Id: <20180925001832.18322-21-keescook@chromium.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180925001832.18322-1-keescook@chromium.org> References: <20180925001832.18322-1-keescook@chromium.org> Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org For what are marked as the Legacy Major LSMs, make them effectively exclusive when selected on the "security=" boot parameter, to handle the future case of when a previously major LSMs become non-exclusive (e.g. when TOMOYO starts blob-sharing). Signed-off-by: Kees Cook --- security/security.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/security/security.c b/security/security.c index e325fcc41f00..a98549b334af 100644 --- a/security/security.c +++ b/security/security.c @@ -103,14 +103,6 @@ static bool __init lsm_allowed(struct lsm_info *lsm) if (!is_enabled(lsm)) return false; - /* Skip major-specific checks if not a major LSM. */ - if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) == 0) - return true; - - /* Disabled if this LSM isn't the chosen one. */ - if (strcmp(lsm->name, chosen_major_lsm) != 0) - return false; - return true; } @@ -188,8 +180,24 @@ static void __init prepare_lsm_enable(void) parse_lsm_enable(chosen_lsm_enable, set_enabled, true); parse_lsm_enable(chosen_lsm_disable, set_enabled, false); + /* Process "security=", if given. */ if (!chosen_major_lsm) chosen_major_lsm = CONFIG_DEFAULT_SECURITY; + if (chosen_major_lsm) { + struct lsm_info *lsm; + + /* + * To match the original "security=" behavior, this + * explicitly does NOT fallback to another Legacy Major + * if the selected one was separately disabled: disable + * all non-matching Legacy Major LSMs. + */ + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { + if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) && + strcmp(lsm->name, chosen_major_lsm) != 0) + set_enabled(lsm, false); + } + } } /** -- 2.17.1