From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [PATCH security-next v2 17/26] LSM: Refactor "security=" in terms of enable/disable Date: Thu, 20 Sep 2018 09:23:29 -0700 Message-ID: <20180920162338.21060-18-keescook@chromium.org> References: <20180920162338.21060-1-keescook@chromium.org> Return-path: In-Reply-To: <20180920162338.21060-1-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: linux-arch.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 5cacbcefbc32..25a019cc4a2b 100644 --- a/security/security.c +++ b/security/security.c @@ -81,14 +81,6 @@ static bool __init lsm_allowed(struct lsm_info *lsm) if (lsm->enabled && !*lsm->enabled) 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; } @@ -150,8 +142,24 @@ int __init security_init(void) i++) INIT_HLIST_HEAD(&list[i]); + /* 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); + } + } /* * Load minor LSMs, with the capability module always first. -- 2.17.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f195.google.com ([209.85.215.195]:36587 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387836AbeITWN6 (ORCPT ); Thu, 20 Sep 2018 18:13:58 -0400 Received: by mail-pg1-f195.google.com with SMTP id d1-v6so4683441pgo.3 for ; Thu, 20 Sep 2018 09:29:41 -0700 (PDT) From: Kees Cook Subject: [PATCH security-next v2 17/26] LSM: Refactor "security=" in terms of enable/disable Date: Thu, 20 Sep 2018 09:23:29 -0700 Message-ID: <20180920162338.21060-18-keescook@chromium.org> In-Reply-To: <20180920162338.21060-1-keescook@chromium.org> References: <20180920162338.21060-1-keescook@chromium.org> Sender: linux-arch-owner@vger.kernel.org List-ID: 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 Message-ID: <20180920162329.Bgv_iH-Dns_OHaSX_H-p1dq-IZXjnXfY7qdE_517cqc@z> 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 5cacbcefbc32..25a019cc4a2b 100644 --- a/security/security.c +++ b/security/security.c @@ -81,14 +81,6 @@ static bool __init lsm_allowed(struct lsm_info *lsm) if (lsm->enabled && !*lsm->enabled) 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; } @@ -150,8 +142,24 @@ int __init security_init(void) i++) INIT_HLIST_HEAD(&list[i]); + /* 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); + } + } /* * Load minor LSMs, with the capability module always first. -- 2.17.1