From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id C13DB6B02FA for ; Wed, 5 Jul 2017 09:50:10 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id 23so41849191wry.4 for ; Wed, 05 Jul 2017 06:50:10 -0700 (PDT) Received: from lhrrgout.huawei.com (lhrrgout.huawei.com. [194.213.3.17]) by mx.google.com with ESMTPS id 62si24340953wmv.29.2017.07.05.06.50.09 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 05 Jul 2017 06:50:09 -0700 (PDT) From: Igor Stoppa Subject: [PATCH 3/3] Make LSM Writable Hooks a command line option Date: Wed, 5 Jul 2017 16:46:28 +0300 Message-ID: <20170705134628.3803-4-igor.stoppa@huawei.com> In-Reply-To: <20170705134628.3803-1-igor.stoppa@huawei.com> References: <20170705134628.3803-1-igor.stoppa@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: keescook@chromium.org, mhocko@kernel.org, jmorris@namei.org, labbott@redhat.com, hch@infradead.org Cc: penguin-kernel@I-love.SAKURA.ne.jp, paul@paul-moore.com, sds@tycho.nsa.gov, casey@schaufler-ca.com, linux-security-module@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, Igor Stoppa This patch shows how it is possible to take advantage of pmalloc: instead of using the build-time option __lsm_ro_after_init, to decide if it is possible to keep the hooks modifiable, now this becomes a boot-time decision, based on the kernel command line. This patch relies on: "Convert security_hook_heads into explicit array of struct list_head" Author: Tetsuo Handa to break free from the static constraint imposed by the previous hardening model, based on __ro_after_init. The default value is disabled, unless SE Linux debugging is turned on. Signed-off-by: Igor Stoppa CC: Tetsuo Handa --- security/security.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/security/security.c b/security/security.c index 44c47b6..c7b4670 100644 --- a/security/security.c +++ b/security/security.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #define MAX_LSM_EVM_XATTR 2 @@ -34,10 +35,19 @@ /* Maximum number of letters for an LSM name string */ #define SECURITY_NAME_MAX 10 -static struct list_head hook_heads[LSM_MAX_HOOK_INDEX] - __lsm_ro_after_init; static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain); +static int dynamic_lsm = IS_ENABLED(CONFIG_SECURITY_SELINUX_DISABLE); + +static __init int set_dynamic_lsm(char *str) +{ + get_option(&str, &dynamic_lsm); + return 0; +} +early_param("dynamic_lsm", set_dynamic_lsm); + +static struct list_head *hook_heads; +static struct gen_pool *sec_pool; char *lsm_names; /* Boot-time LSM user choice */ static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] = @@ -62,6 +72,11 @@ int __init security_init(void) { enum security_hook_index i; + sec_pool = pmalloc_create_pool("security", PMALLOC_DEFAULT_ALLOC_ORDER); + BUG_ON(!sec_pool); + hook_heads = pmalloc(sec_pool, + sizeof(struct list_head) * LSM_MAX_HOOK_INDEX); + BUG_ON(!hook_heads); for (i = 0; i < LSM_MAX_HOOK_INDEX; i++) INIT_LIST_HEAD(&hook_heads[i]); pr_info("Security Framework initialized\n"); @@ -77,7 +92,8 @@ int __init security_init(void) * Load all the remaining security modules. */ do_security_initcalls(); - + if (!dynamic_lsm) + pmalloc_protect_pool(sec_pool); return 0; } -- 2.9.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org