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 8D7616B02FA for ; Mon, 5 Jun 2017 15:24:26 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id v102so12588567wrc.8 for ; Mon, 05 Jun 2017 12:24:26 -0700 (PDT) Received: from lhrrgout.huawei.com (lhrrgout.huawei.com. [194.213.3.17]) by mx.google.com with ESMTPS id l4si16071333wre.293.2017.06.05.12.24.25 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 05 Jun 2017 12:24:25 -0700 (PDT) From: Igor Stoppa Subject: [PATCH 4/5] Make LSM Writable Hooks a command line option Date: Mon, 5 Jun 2017 22:22:15 +0300 Message-ID: <20170605192216.21596-5-igor.stoppa@huawei.com> In-Reply-To: <20170605192216.21596-1-igor.stoppa@huawei.com> References: <20170605192216.21596-1-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 Cc: penguin-kernel@I-love.SAKURA.ne.jp, paul@paul-moore.com, sds@tycho.nsa.gov, casey@schaufler-ca.com, hch@infradead.org, labbott@redhat.com, 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. Signed-off-by: Igor Stoppa CC: Tetsuo Handa --- init/main.c | 2 ++ security/security.c | 29 ++++++++++++++++++++++++++--- 2 files changed, 28 insertions(+), 3 deletions(-) diff --git a/init/main.c b/init/main.c index f866510..7850887 100644 --- a/init/main.c +++ b/init/main.c @@ -485,6 +485,7 @@ static void __init mm_init(void) ioremap_huge_init(); } +extern int __init pmalloc_init(void); asmlinkage __visible void __init start_kernel(void) { char *command_line; @@ -653,6 +654,7 @@ asmlinkage __visible void __init start_kernel(void) proc_caches_init(); buffer_init(); key_init(); + pmalloc_init(); security_init(); dbg_late_init(); vfs_caches_init(); diff --git a/security/security.c b/security/security.c index c492f68..4285545 100644 --- a/security/security.c +++ b/security/security.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #define MAX_LSM_EVM_XATTR 2 @@ -33,8 +34,17 @@ /* 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 int security_debug; + +static __init int set_security_debug(char *str) +{ + get_option(&str, &security_debug); + return 0; +} +early_param("security_debug", set_security_debug); + +static struct list_head *hook_heads; +static struct pmalloc_pool *sec_pool; char *lsm_names; /* Boot-time LSM user choice */ static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] = @@ -59,6 +69,13 @@ int __init security_init(void) { enum security_hook_index i; + sec_pool = pmalloc_create_pool("security"); + if (!sec_pool) + goto error_pool; + hook_heads = pmalloc(sizeof(struct list_head) * LSM_MAX_HOOK_INDEX, + sec_pool); + if (!hook_heads) + goto error_heads; for (i = 0; i < LSM_MAX_HOOK_INDEX; i++) INIT_LIST_HEAD(&hook_heads[i]); pr_info("Security Framework initialized\n"); @@ -74,8 +91,14 @@ int __init security_init(void) * Load all the remaining security modules. */ do_security_initcalls(); - + if (!security_debug) + pmalloc_protect_pool(sec_pool); return 0; + +error_heads: + pmalloc_destroy_pool(sec_pool); +error_pool: + return -ENOMEM; } /* Save user chosen LSM */ -- 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