From: Kees Cook <keescook@chromium.org>
To: James Morris <jmorris@namei.org>
Cc: Kees Cook <keescook@chromium.org>,
Casey Schaufler <casey@schaufler-ca.com>,
John Johansen <john.johansen@canonical.com>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Paul Moore <paul@paul-moore.com>,
Stephen Smalley <sds@tycho.nsa.gov>,
"Schaufler, Casey" <casey.schaufler@intel.com>,
LSM <linux-security-module@vger.kernel.org>,
Jonathan Corbet <corbet@lwn.net>,
linux-doc@vger.kernel.org, linux-arch@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH security-next v2 14/26] LSM: Lift LSM selection out of individual LSMs
Date: Thu, 20 Sep 2018 09:23:26 -0700 [thread overview]
Message-ID: <20180920162338.21060-15-keescook@chromium.org> (raw)
In-Reply-To: <20180920162338.21060-1-keescook@chromium.org>
As a prerequisite to adjusting LSM selection logic in the future, this
moves the selection logic up out of the individual major LSMs, making
their init functions only run when actually enabled.
Signed-off-by: Kees Cook <keescook@chromium.org>
---
include/linux/lsm_hooks.h | 1 -
security/apparmor/lsm.c | 6 ---
security/security.c | 76 ++++++++++++++++++++++----------------
security/selinux/hooks.c | 10 -----
security/smack/smack_lsm.c | 3 --
security/tomoyo/tomoyo.c | 2 -
6 files changed, 45 insertions(+), 53 deletions(-)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 118e12f678df..ec1c0a97dfe3 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2091,7 +2091,6 @@ static inline void security_delete_hooks(struct security_hook_list *hooks,
#define __lsm_ro_after_init __ro_after_init
#endif /* CONFIG_SECURITY_WRITABLE_HOOKS */
-extern int __init security_module_enable(const char *module);
extern void __init capability_add_hooks(void);
#ifdef CONFIG_SECURITY_YAMA
extern void __init yama_add_hooks(void);
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index d03133a267f2..5399c2f03536 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1542,12 +1542,6 @@ static int __init apparmor_init(void)
{
int error;
- if (!apparmor_enabled || !security_module_enable("apparmor")) {
- aa_info_message("AppArmor disabled by boot time parameter");
- apparmor_enabled = false;
- return 0;
- }
-
aa_secids_init();
error = aa_setup_dfa_engine();
diff --git a/security/security.c b/security/security.c
index a886a978214a..85533d4e534a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -52,33 +52,70 @@ static bool debug __initdata;
pr_info(__VA_ARGS__); \
} while (0)
+/* Mark an LSM's enabled flag, if it exists. */
+static void __init set_enabled(struct lsm_info *lsm, bool enabled)
+{
+ if (lsm->enabled)
+ *lsm->enabled = enabled;
+}
+
+/* Is an LSM allowed to be enabled? */
+static bool __init lsm_allowed(struct lsm_info *lsm)
+{
+ /* Skip if the LSM is disabled. */
+ 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_lsm) != 0)
+ return false;
+
+ return true;
+}
+
+/* Check if LSM should be enabled. Mark any that are disabled. */
+static void __init maybe_initialize_lsm(struct lsm_info *lsm)
+{
+ int enabled = lsm_allowed(lsm);
+
+ /* Record enablement. */
+ set_enabled(lsm, enabled);
+
+ /* If selected, initialize the LSM. */
+ if (enabled) {
+ int ret;
+
+ init_debug("initializing %s\n", lsm->name);
+ ret = lsm->init();
+ WARN(ret, "%s failed to initialize: %d\n", lsm->name, ret);
+ }
+}
+
static void __init ordered_lsm_init(void)
{
struct lsm_info *lsm;
- int ret;
for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) != 0)
continue;
- init_debug("initializing %s\n", lsm->name);
- ret = lsm->init();
- WARN(ret, "%s failed to initialize: %d\n", lsm->name, ret);
+ maybe_initialize_lsm(lsm);
}
}
static void __init major_lsm_init(void)
{
struct lsm_info *lsm;
- int ret;
for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) == 0)
continue;
- init_debug("initializing %s\n", lsm->name);
- ret = lsm->init();
- WARN(ret, "%s failed to initialize: %d\n", lsm->name, ret);
+ maybe_initialize_lsm(lsm);
}
}
@@ -168,29 +205,6 @@ static int lsm_append(char *new, char **result)
return 0;
}
-/**
- * security_module_enable - Load given security module on boot ?
- * @module: the name of the module
- *
- * Each LSM must pass this method before registering its own operations
- * to avoid security registration races. This method may also be used
- * to check if your LSM is currently loaded during kernel initialization.
- *
- * Returns:
- *
- * true if:
- *
- * - The passed LSM is the one chosen by user at boot time,
- * - or the passed LSM is configured as the default and the user did not
- * choose an alternate LSM at boot time.
- *
- * Otherwise, return false.
- */
-int __init security_module_enable(const char *module)
-{
- return !strcmp(module, chosen_lsm);
-}
-
/**
* security_add_hooks - Add a modules hooks to the hook lists.
* @hooks: the hooks to add
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 3f999ed98cfd..409a9252aeb6 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7133,16 +7133,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
static __init int selinux_init(void)
{
- if (!security_module_enable("selinux")) {
- selinux_enabled = 0;
- return 0;
- }
-
- if (!selinux_enabled) {
- pr_info("SELinux: Disabled at boot.\n");
- return 0;
- }
-
pr_info("SELinux: Initializing.\n");
memset(&selinux_state, 0, sizeof(selinux_state));
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 4aef844fc0e2..e79fad43a8e3 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4834,9 +4834,6 @@ static __init int smack_init(void)
struct cred *cred;
struct task_smack *tsp;
- if (!security_module_enable("smack"))
- return 0;
-
smack_inode_cache = KMEM_CACHE(inode_smack, 0);
if (!smack_inode_cache)
return -ENOMEM;
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index 528b6244a648..39bb994ebe09 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -540,8 +540,6 @@ static int __init tomoyo_init(void)
{
struct cred *cred = (struct cred *) current_cred();
- if (!security_module_enable("tomoyo"))
- return 0;
/* register ourselves with the security framework */
security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");
printk(KERN_INFO "TOMOYO Linux initialized\n");
--
2.17.1
next prev parent reply other threads:[~2018-09-20 16:24 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-20 16:23 [PATCH security-next v2 00/26] LSM: Explict LSM ordering Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 01/26] LSM: Correctly announce start of LSM initialization Kees Cook
2018-09-20 23:39 ` Casey Schaufler
2018-09-20 16:23 ` [PATCH security-next v2 02/26] vmlinux.lds.h: Avoid copy/paste of security_init section Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 03/26] LSM: Rename .security_initcall section to .lsm_info Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 04/26] LSM: Remove initcall tracing Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 05/26] LSM: Convert from initcall to struct lsm_info Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 06/26] vmlinux.lds.h: Move LSM_TABLE into INIT_DATA Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 07/26] LSM: Convert security_initcall() into DEFINE_LSM() Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 08/26] LSM: Record LSM name in struct lsm_info Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 09/26] LSM: Provide init debugging infrastructure Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 10/26] LSM: Don't ignore initialization failures Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 11/26] LSM: Introduce LSM_FLAG_LEGACY_MAJOR Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 12/26] LSM: Provide separate ordered initialization Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 13/26] LSM: Plumb visibility into optional "enabled" state Kees Cook
2018-09-20 16:23 ` Kees Cook [this message]
2018-09-20 16:23 ` [PATCH security-next v2 15/26] LSM: Introduce lsm.enable= and lsm.disable= Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 16/26] LSM: Prepare for reorganizing "security=" logic Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 17/26] LSM: Refactor "security=" in terms of enable/disable Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 18/26] LSM: Build ordered list of ordered LSMs for init Kees Cook
2018-09-21 0:04 ` Casey Schaufler
2018-09-21 0:37 ` Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 19/26] LSM: Introduce CONFIG_LSM_ORDER Kees Cook
2018-09-21 0:10 ` Casey Schaufler
2018-09-21 0:14 ` Casey Schaufler
2018-09-20 16:23 ` [PATCH security-next v2 20/26] LSM: Introduce "lsm.order=" for boottime ordering Kees Cook
2018-09-21 0:12 ` Casey Schaufler
2018-09-21 0:40 ` Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 21/26] LoadPin: Initialize as ordered LSM Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 22/26] Yama: " Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 23/26] LSM: Introduce enum lsm_order Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 24/26] capability: Mark as LSM_ORDER_FIRST Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 25/26] LSM: Separate idea of "major" LSM from "exclusive" LSM Kees Cook
2018-09-20 16:23 ` [PATCH security-next v2 26/26] LSM: Add all exclusive LSMs to ordered initialization Kees Cook
2018-09-21 0:25 ` Casey Schaufler
2018-09-21 0:45 ` Kees Cook
2018-09-21 1:10 ` Casey Schaufler
2018-09-21 1:39 ` John Johansen
2018-09-21 2:05 ` Kees Cook
2018-09-21 2:14 ` John Johansen
2018-09-21 3:02 ` Kees Cook
2018-09-21 13:19 ` John Johansen
2018-09-21 14:57 ` Casey Schaufler
2018-09-20 20:14 ` [PATCH security-next v2 00/26] LSM: Explict LSM ordering Martin Steigerwald
2018-09-20 21:55 ` Kees Cook
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