diff --git a/Documentation/admin-guide/LSM/index.rst b/Documentation/admin-guide/LSM/index.rst
index 9842e21afd4a..d3d8af174042 100644
--- a/Documentation/admin-guide/LSM/index.rst
+++ b/Documentation/admin-guide/LSM/index.rst
@@ -17,10 +17,16 @@ MAC extensions, other extensions can be built using the LSM to provide
 specific changes to system operation when these tweaks are not available
 in the core functionality of Linux itself.
 
-The Linux capabilities modules will always be included. This may be
-followed by any number of "minor" modules and at most one "major" module.
-For more details on capabilities, see ``capabilities(7)`` in the Linux
-man-pages project.
+The Linux capabilities modules will always be included. For more details
+on capabilities, see ``capabilities(7)`` in the Linux man-pages project.
+
+Security modules that do not use the security data blobs maintained
+by the LSM infrastructure are considered "minor" modules. These may be
+included at compile time and stacked explicitly. Security modules that
+use the LSM maintained security blobs are considered "major" modules.
+These may only be stacked if the CONFIG_LSM_STACKED configuration
+option is used. If this is chosen all of the security modules selected
+will be used.
 
 A list of the active security modules can be found by reading
 ``/sys/kernel/security/lsm``. This is a comma separated list, and
diff --git a/fs/proc/base.c b/fs/proc/base.c
index a096e90fc12e..e6ee90483916 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2593,6 +2593,18 @@ static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
 	.setattr	= proc_setattr, \
 }
 
+#ifdef CONFIG_SECURITY_SELINUX
+static const struct pid_entry selinux_attr_dir_stuff[] = {
+	ATTR("selinux", "current",	0666),
+	ATTR("selinux", "prev",		0444),
+	ATTR("selinux", "exec",		0666),
+	ATTR("selinux", "fscreate",	0666),
+	ATTR("selinux", "keycreate",	0666),
+	ATTR("selinux", "sockcreate",	0666),
+};
+LSM_DIR_OPS(selinux);
+#endif
+
 #ifdef CONFIG_SECURITY_SMACK
 static const struct pid_entry smack_attr_dir_stuff[] = {
 	ATTR("smack", "current",	0666),
@@ -2600,6 +2612,15 @@ static const struct pid_entry smack_attr_dir_stuff[] = {
 LSM_DIR_OPS(smack);
 #endif
 
+#ifdef CONFIG_SECURITY_APPARMOR
+static const struct pid_entry apparmor_attr_dir_stuff[] = {
+	ATTR("apparmor", "current",	0666),
+	ATTR("apparmor", "prev",	0444),
+	ATTR("apparmor", "exec",	0666),
+};
+LSM_DIR_OPS(apparmor);
+#endif
+
 static const struct pid_entry attr_dir_stuff[] = {
 	ATTR(NULL, "current",		0666),
 	ATTR(NULL, "prev",		0444),
@@ -2607,10 +2628,18 @@ static const struct pid_entry attr_dir_stuff[] = {
 	ATTR(NULL, "fscreate",		0666),
 	ATTR(NULL, "keycreate",		0666),
 	ATTR(NULL, "sockcreate",	0666),
+#ifdef CONFIG_SECURITY_SELINUX
+	DIR("selinux",			0555,
+	    proc_selinux_attr_dir_inode_ops, proc_selinux_attr_dir_ops),
+#endif
 #ifdef CONFIG_SECURITY_SMACK
 	DIR("smack",			0555,
 	    proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
 #endif
+#ifdef CONFIG_SECURITY_APPARMOR
+	DIR("apparmor",			0555,
+	    proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
+#endif
 };
 
 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index cae3f6591044..84643a3ae378 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1975,7 +1975,7 @@ 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 bool __init security_module_enable(const char *lsm, const bool stacked);
 extern void __init capability_add_hooks(void);
 #ifdef CONFIG_SECURITY_YAMA
 extern void __init yama_add_hooks(void);
diff --git a/security/Kconfig b/security/Kconfig
index f3464fb5a8b0..a14d50b45b6c 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -36,6 +36,28 @@ config SECURITY_WRITABLE_HOOKS
 	bool
 	default n
 
+config SECURITY_STACKING
+	bool "Security module stacking"
+	depends on SECURITY
+	help
+	  Allows multiple major security modules to be stacked.
+	  Modules are invoked in the order registered with a
+	  "bail on fail" policy, in which the infrastructure
+	  will stop processing once a denial is detected. Not
+	  all modules can be stacked. SELinux and Smack are
+	  known to be incompatible. User space components may
+	  have trouble identifying the security module providing
+	  data in some cases.
+
+	  If you select this option you will have to select which
+	  of the stackable modules you wish to be active. The
+	  "Default security module" will be ignored. The boot line
+	  "security=" option can be used to specify that one of
+	  the modules identifed for stacking should be used instead
+	  of the entire stack.
+
+	  If you are unsure how to answer this question, answer N.
+
 config SECURITY_LSM_DEBUG
 	bool "Enable debugging of the LSM infrastructure"
 	depends on SECURITY
@@ -225,6 +247,9 @@ source security/yama/Kconfig
 
 source security/integrity/Kconfig
 
+menu "Security Module Selection"
+	visible if !SECURITY_STACKING
+
 choice
 	prompt "Default security module"
 	default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
@@ -264,3 +289,64 @@ config DEFAULT_SECURITY
 
 endmenu
 
+menu "Security Module Stack"
+	visible if SECURITY_STACKING
+
+choice
+	prompt "Stacked 'extreme' security module"
+	default SECURITY_SELINUX_STACKED if SECURITY_SELINUX
+	default SECURITY_SMACK_STACKED if SECURITY_SMACK
+	default SECURITY_APPARMOR_STACKED if SECURITY_APPARMOR
+
+	help
+	  Enable an extreme security module. These modules cannot
+	  be used at the same time.
+
+	config SECURITY_SELINUX_STACKED
+		bool "SELinux" if SECURITY_SELINUX=y
+	help
+	  This option instructs the system to use the SELinux checks.
+	  At this time the Smack security module is incompatible with this
+	  module.
+	  At this time the AppArmor security module is incompatible with this
+	  module.
+
+	config SECURITY_SMACK_STACKED
+		bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
+	help
+	  This option instructs the system to use the Smack checks.
+	  At this time the SELinux security module is incompatible with this
+	  module.
+	  At this time the AppArmor security module is incompatible with this
+	  module.
+
+	config SECURITY_APPARMOR_STACKED
+		bool "AppArmor" if SECURITY_APPARMOR=y
+	help
+	  This option instructs the system to use the AppArmor checks.
+	  At this time the SELinux security module is incompatible with this
+	  module.
+	  At this time the Smack security module is incompatible with this
+	  module.
+
+	config SECURITY_NOTHING_STACKED
+		bool "Use no 'extreme' security module"
+	help
+	  Use none of the SELinux, Smack or AppArmor security module.
+
+endchoice
+
+config SECURITY_TOMOYO_STACKED
+	bool "TOMOYO support is enabled by default"
+	depends on SECURITY_TOMOYO && SECURITY_STACKING
+	default n
+	help
+	  This option instructs the system to use the TOMOYO checks.
+	  If not selected the module will not be invoked.
+	  Stacked security modules may interact in unexpected ways.
+
+	  If you are unsure how to answer this question, answer N.
+
+endmenu
+
+endmenu
diff --git a/security/apparmor/include/context.h b/security/apparmor/include/context.h
index c6e106a533e8..c6d5dbbd18b0 100644
--- a/security/apparmor/include/context.h
+++ b/security/apparmor/include/context.h
@@ -55,9 +55,15 @@ int aa_set_current_hat(struct aa_label *label, u64 token);
 int aa_restore_previous_label(u64 cookie);
 struct aa_label *aa_get_task_label(struct task_struct *task);
 
+extern struct lsm_blob_sizes apparmor_blob_sizes;
+
 static inline struct aa_task_ctx *apparmor_cred(const struct cred *cred)
 {
+#ifdef CONFIG_SECURITY_STACKING
+	return cred->security + apparmor_blob_sizes.lbs_cred;
+#else
 	return cred->security;
+#endif
 }
 
 /**
@@ -89,7 +95,11 @@ static inline struct aa_label *aa_get_newest_cred_label(const struct cred *cred)
 
 static inline struct aa_file_ctx *apparmor_file(const struct file *file)
 {
+#ifdef CONFIG_SECURITY_STACKING
+	return file->f_security + apparmor_blob_sizes.lbs_file;
+#else
 	return file->f_security;
+#endif
 }
 
 /**
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 8edbf79062cd..b36d08f5ce1d 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1467,7 +1467,9 @@ static int __init apparmor_init(void)
 	int error;
 
 	if (!finish) {
-		if (apparmor_enabled && security_module_enable("apparmor"))
+		if (apparmor_enabled &&
+		    security_module_enable("apparmor",
+				IS_ENABLED(CONFIG_SECURITY_APPARMOR_STACKED)))
 			security_add_blobs(&apparmor_blob_sizes);
 		else
 			apparmor_enabled = 0;
@@ -1475,7 +1477,9 @@ static int __init apparmor_init(void)
 		return 0;
 	}
 
-	if (!apparmor_enabled || !security_module_enable("apparmor")) {
+	if (!apparmor_enabled ||
+	    !security_module_enable("apparmor",
+				IS_ENABLED(CONFIG_SECURITY_APPARMOR_STACKED))) {
 		aa_info_message("AppArmor disabled by boot time parameter");
 		apparmor_enabled = 0;
 		return 0;
diff --git a/security/security.c b/security/security.c
index 8439acd36160..a306a5447d43 100644
--- a/security/security.c
+++ b/security/security.c
@@ -35,6 +35,7 @@
 
 /* Maximum number of letters for an LSM name string */
 #define SECURITY_NAME_MAX	10
+#define MODULE_STACK		"(stacking)"
 
 struct security_hook_heads security_hook_heads __lsm_ro_after_init;
 static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain);
@@ -47,7 +48,11 @@ static struct lsm_blob_sizes blob_sizes;
 
 /* Boot-time LSM user choice */
 static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
+#ifdef CONFIG_SECURITY_STACKING
+	MODULE_STACK;
+#else
 	CONFIG_DEFAULT_SECURITY;
+#endif
 
 static void __init do_security_initcalls(void)
 {
@@ -167,6 +172,7 @@ static int lsm_append(char *new, char **result)
 /**
  * security_module_enable - Load given security module on boot ?
  * @module: the name of the module
+ * @stacked: indicates that the module wants to be stacked
  *
  * Each LSM must pass this method before registering its own operations
  * to avoid security registration races. This method may also be used
@@ -182,9 +188,29 @@ static int lsm_append(char *new, char **result)
  *
  * Otherwise, return false.
  */
-int __init security_module_enable(const char *module)
+bool __init security_module_enable(const char *lsm, const bool stacked)
 {
-	return !strcmp(module, chosen_lsm);
+#ifdef CONFIG_SECURITY_STACKING
+	/*
+	 * Module defined on the command line security=XXXX
+	 */
+	if (strcmp(chosen_lsm, MODULE_STACK)) {
+		if (!strcmp(lsm, chosen_lsm)) {
+			pr_info("Command line sets the %s security module.\n",
+				lsm);
+			return true;
+		}
+		return false;
+	}
+	/*
+	 * Module configured as stacked.
+	 */
+	return stacked;
+#else
+	if (strcmp(lsm, chosen_lsm) == 0)
+		return true;
+	return false;
+#endif
 }
 
 /**
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index cfee70096f97..a3466517c55c 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6300,7 +6300,8 @@ static __init int selinux_init(void)
 {
 	static int finish;
 
-	if (!security_module_enable("selinux")) {
+	if (!security_module_enable("selinux",
+				IS_ENABLED(CONFIG_SECURITY_SELINUX_STACKED))) {
 		selinux_enabled = 0;
 		return 0;
 	}
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index f2f1e2d15eb8..7abb443c2ed2 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -155,12 +155,20 @@ extern struct lsm_blob_sizes selinux_blob_sizes;
 
 static inline struct task_security_struct *selinux_cred(const struct cred *cred)
 {
+#ifdef CONFIG_SECURITY_STACKING
+	return cred->security + selinux_blob_sizes.lbs_cred;
+#else
 	return cred->security;
+#endif
 }
 
 static inline struct file_security_struct *selinux_file(const struct file *file)
 {
+#ifdef CONFIG_SECURITY_STACKING
+	return file->f_security + selinux_blob_sizes.lbs_file;
+#else
 	return file->f_security;
+#endif
 }
 
 static inline struct inode_security_struct *selinux_inode(
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 1b875c2f3d9d..e7611de071f1 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -336,6 +336,7 @@ extern struct smack_known *smack_syslog_label;
 extern struct smack_known *smack_unconfined;
 #endif
 extern int smack_ptrace_rule;
+extern struct lsm_blob_sizes smack_blob_sizes;
 
 extern struct smack_known smack_known_floor;
 extern struct smack_known smack_known_hat;
@@ -358,12 +359,20 @@ extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS];
 
 static inline struct task_smack *smack_cred(const struct cred *cred)
 {
+#ifdef CONFIG_SECURITY_STACKING
+	return cred->security + smack_blob_sizes.lbs_cred;
+#else
 	return cred->security;
+#endif
 }
 
 static inline struct smack_known **smack_file(const struct file *file)
 {
+#ifdef CONFIG_SECURITY_STACKING
+	return file->f_security + smack_blob_sizes.lbs_file;
+#else
 	return file->f_security;
+#endif
 }
 
 static inline struct inode_smack *smack_inode(const struct inode *inode)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 4588c48aab86..e3f32f4d322a 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3427,18 +3427,16 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value)
 {
 	struct smack_known *skp = smk_of_task_struct(p);
 	char *cp;
-	int slen;
 
-	if (strcmp(name, "current") != 0)
+	if (strcmp(name, "current") == 0) {
+		cp = kstrdup(skp->smk_known, GFP_KERNEL);
+		if (cp == NULL)
+			return -ENOMEM;
+	} else
 		return -EINVAL;
 
-	cp = kstrdup(skp->smk_known, GFP_KERNEL);
-	if (cp == NULL)
-		return -ENOMEM;
-
-	slen = strlen(cp);
 	*value = cp;
-	return slen;
+	return strlen(cp);
 }
 
 /**
@@ -4594,7 +4592,8 @@ static __init int smack_init(void)
 	struct cred *cred = (struct cred *) current->cred;
 	struct task_smack *tsp;
 
-	if (!security_module_enable("smack"))
+	if (!security_module_enable("smack",
+				IS_ENABLED(CONFIG_SECURITY_SMACK_STACKED)))
 		return 0;
 
 	if (!finish) {
diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h
index cbcfccc84784..2eed9d44eec1 100644
--- a/security/tomoyo/common.h
+++ b/security/tomoyo/common.h
@@ -1085,6 +1085,7 @@ extern struct tomoyo_domain_info tomoyo_kernel_domain;
 extern struct tomoyo_policy_namespace tomoyo_kernel_namespace;
 extern unsigned int tomoyo_memory_quota[TOMOYO_MAX_MEMORY_STAT];
 extern unsigned int tomoyo_memory_used[TOMOYO_MAX_MEMORY_STAT];
+extern struct lsm_blob_sizes tomoyo_blob_sizes;
 
 /********** Inlined functions. **********/
 
@@ -1204,7 +1205,11 @@ static inline void tomoyo_put_group(struct tomoyo_group *group)
  */
 static inline struct tomoyo_domain_info **tomoyo_cred(const struct cred *cred)
 {
+#ifdef CONFIG_SECURITY_STACKING
+	return cred->security + tomoyo_blob_sizes.lbs_cred;
+#else
 	return cred->security;
+#endif
 }
 
 /**
@@ -1214,8 +1219,13 @@ static inline struct tomoyo_domain_info **tomoyo_cred(const struct cred *cred)
  */
 static inline struct tomoyo_domain_info *tomoyo_domain(void)
 {
-	struct tomoyo_domain_info **blob = tomoyo_cred(current_cred());
+	const struct cred *cred = current_cred();
+	struct tomoyo_domain_info **blob;
+
+	if (cred->security == NULL)
+		return NULL;
 
+	blob = tomoyo_cred(cred);
 	return *blob;
 }
 
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index 1224a59291fb..32173de284f8 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -561,7 +561,8 @@ static int __init tomoyo_init(void)
 	struct cred *cred = (struct cred *) current_cred();
 	struct tomoyo_domain_info **blob;
 
-	if (!security_module_enable("tomoyo"))
+	if (!security_module_enable("tomoyo",
+				IS_ENABLED(CONFIG_SECURITY_TOMOYO_STACKED)))
 		return 0;
 
 	if (!finish) {
