@@ -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
@@ -37,6 +43,14 @@ security module and contains all its special files. The files directly
in ``/proc/.../attr`` remain as legacy interfaces for modules that provide
subdirectories.
+The files named "context" in the attr directories contain the
+same information as the "current" files, but formatted to
+identify the module it comes from.
+
+if selinux is the active security module:
+ /proc/self/attr/context could contain selinux='unconfined_t'
+ /proc/self/attr/selinux/context could contain selinux='unconfined_t'
+
.. toctree::
:maxdepth: 1
@@ -2592,13 +2592,37 @@ 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),
+ ATTR("selinux", "context", 0666),
+};
+LSM_DIR_OPS(selinux);
+#endif
+
#ifdef CONFIG_SECURITY_SMACK
static const struct pid_entry smack_attr_dir_stuff[] = {
ATTR("smack", "current", 0666),
+ ATTR("smack", "context", 0666),
};
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),
+ ATTR("apparmor", "context", 0666),
+};
+LSM_DIR_OPS(apparmor);
+#endif
+
static const struct pid_entry attr_dir_stuff[] = {
ATTR(NULL, "current", 0666),
ATTR(NULL, "prev", 0444),
@@ -2606,10 +2630,19 @@ static const struct pid_entry attr_dir_stuff[] = {
ATTR(NULL, "fscreate", 0666),
ATTR(NULL, "keycreate", 0666),
ATTR(NULL, "sockcreate", 0666),
+ ATTR(NULL, "context", 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)
@@ -1979,7 +1979,7 @@ 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);
@@ -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 +289,72 @@ 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
+
+ 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
+ Add the SELinux security module to the stack. At this
+ time the Smack security module is incompatible with this
+ module.
+ Please be sure your user space code is accomodating of
+ this security module.
+
+ config SECURITY_SMACK_STACKED
+ bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
+ help
+ Add the Smack security module to the stack. At this
+ time the SELinux security module is incompatible with this
+ module.
+ Please be sure your user space code is accomodating of
+ this security module.
+
+ config SECURITY_NOTHING_STACKED
+ bool "Use no 'extreme' security module"
+ help
+ Add neither the SELinux security module nor the Smack security
+ module to the stack.
+ Please be sure your user space code does not require either of
+ these security modules.
+
+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.
+ Please be sure your user space code is accomodating of
+ multiple security modules.
+
+ If you are unsure how to answer this question, answer N.
+
+config SECURITY_APPARMOR_STACKED
+ bool "AppArmor support is enabled by default"
+ depends on SECURITY_APPARMOR && SECURITY_STACKING
+ default n
+ help
+ This option instructs the system to use the AppArmor checks.
+ If not selected the module will not be invoked.
+ Stacked security modules may interact in unexpected ways.
+ Please be sure your user space code is accomodating of
+ multiple security modules.
+
+ If you are unsure how to answer this question, answer N.
+
+endmenu
+
+endmenu
@@ -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
}
/**
@@ -496,9 +496,13 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
const struct cred *cred = get_task_cred(task);
struct aa_task_ctx *ctx = cred_ctx(cred);
struct aa_label *label = NULL;
+ char *vp;
+ char *np;
if (strcmp(name, "current") == 0)
label = aa_get_newest_label(ctx->label);
+ else if (strcmp(name, "context") == 0 && ctx->label)
+ label = aa_get_newest_label(ctx->label);
else if (strcmp(name, "prev") == 0 && ctx->previous)
label = aa_get_newest_label(ctx->previous);
else if (strcmp(name, "exec") == 0 && ctx->onexec)
@@ -506,8 +510,29 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
else
error = -EINVAL;
- if (label)
- error = aa_getprocattr(label, value);
+ if (label == NULL)
+ goto put_out;
+
+ error = aa_getprocattr(label, &vp);
+ if (error < 0)
+ goto put_out;
+
+ if (strcmp(name, "context") == 0) {
+ *value = kasprintf(GFP_KERNEL, "apparmor='%s'", vp);
+ if (*value == NULL) {
+ error = -ENOMEM;
+ goto put_out;
+ }
+ np = strchr(*value, '\n');
+ if (np != NULL) {
+ np[0] = '\'';
+ np[1] = '\0';
+ }
+ error = strlen(*value);
+ } else
+ *value = vp;
+
+put_out:
aa_put_label(label);
put_cred(cred);
@@ -546,7 +571,7 @@ static int apparmor_setprocattr(const char *name, void *value,
goto out;
arg_size = size - (args - (largs ? largs : (char *) value));
- if (strcmp(name, "current") == 0) {
+ if (strcmp(name, "current") == 0 || strcmp(name, "context") == 0) {
if (strcmp(command, "changehat") == 0) {
error = aa_setprocattr_changehat(args, arg_size,
AA_CHANGE_NOFLAGS);
@@ -570,7 +595,10 @@ static int apparmor_setprocattr(const char *name, void *value,
else
goto fail;
} else
- /* only support the "current" and "exec" process attributes */
+ /*
+ * only support the "current", "context" and "exec"
+ * process attributes
+ */
goto fail;
if (!error)
@@ -1014,13 +1042,17 @@ 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);
finish = 1;
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;
@@ -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);
@@ -44,7 +45,11 @@ 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)
{
@@ -153,6 +158,7 @@ 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
@@ -168,9 +174,29 @@ 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
}
/**
@@ -1661,8 +1687,49 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
char **value)
{
struct security_hook_list *hp;
+ char *vp;
+ char *cp = NULL;
+ int trc;
int rc;
+ /*
+ * "context" requires work here in addition to what
+ * the modules provide.
+ */
+ if (strcmp(name, "context") == 0) {
+ *value = NULL;
+ rc = -EINVAL;
+ list_for_each_entry(hp,
+ &security_hook_heads.getprocattr, list) {
+ if (lsm != NULL && strcmp(lsm, hp->lsm))
+ continue;
+ trc = hp->hook.getprocattr(p, "context", &vp);
+ if (trc == -ENOENT)
+ continue;
+ if (trc <= 0) {
+ kfree(*value);
+ return trc;
+ }
+ rc = trc;
+ if (*value == NULL) {
+ *value = vp;
+ } else {
+ cp = kasprintf(GFP_KERNEL, "%s,%s", *value, vp);
+ if (cp == NULL) {
+ kfree(*value);
+ kfree(vp);
+ return -ENOMEM;
+ }
+ kfree(*value);
+ kfree(vp);
+ *value = cp;
+ }
+ }
+ if (rc > 0)
+ return strlen(*value);
+ return rc;
+ }
+
list_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
if (lsm != NULL && strcmp(lsm, hp->lsm))
continue;
@@ -1678,6 +1745,77 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
{
struct security_hook_list *hp;
int rc;
+ char *local;
+ char *cp;
+ int slen;
+ int failed = 0;
+
+ /*
+ * If lsm is NULL look at all the modules to find one
+ * that processes name. If lsm is not NULL only look at
+ * that module.
+ *
+ * "context" is handled directly here.
+ */
+ if (strcmp(name, "context") == 0) {
+ /*
+ * First verify that the input is acceptable.
+ * lsm1='v1'lsm2='v2'lsm3='v3'
+ *
+ * A note on the use of strncmp() below.
+ * The check is for the substring at the beginning of cp.
+ * The kzalloc of size + 1 ensures a terminated string.
+ */
+ rc = -EINVAL;
+ local = kzalloc(size + 1, GFP_KERNEL);
+ memcpy(local, value, size);
+ cp = local;
+ list_for_each_entry(hp, &security_hook_heads.setprocattr,
+ list) {
+ if (lsm != NULL && strcmp(lsm, hp->lsm))
+ continue;
+ if (cp[0] == ',') {
+ if (cp == local)
+ goto free_out;
+ cp++;
+ }
+ slen = strlen(hp->lsm);
+ if (strncmp(cp, hp->lsm, slen))
+ goto free_out;
+ cp += slen;
+ if (cp[0] != '=' || cp[1] != '\'' || cp[2] == '\'')
+ goto free_out;
+ for (cp += 2; cp[0] != '\''; cp++)
+ if (cp[0] == '\0')
+ goto free_out;
+ cp++;
+ }
+
+ cp = local;
+ list_for_each_entry(hp, &security_hook_heads.setprocattr,
+ list) {
+ if (lsm != NULL && strcmp(lsm, hp->lsm))
+ continue;
+ if (cp[0] == ',')
+ cp++;
+ cp += strlen(hp->lsm) + 2;
+ for (slen = 0; cp[slen] != '\''; slen++)
+ ;
+ cp[slen] = '\0';
+
+ rc = hp->hook.setprocattr("context", cp, slen);
+ if (rc < 0)
+ failed = rc;
+ cp += slen + 1;
+ }
+ if (failed != 0)
+ rc = failed;
+ else
+ rc = size;
+free_out:
+ kfree(local);
+ return rc;
+ }
list_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
if (lsm != NULL && strcmp(lsm, hp->lsm))
@@ -5733,6 +5733,8 @@ static int selinux_getprocattr(struct task_struct *p,
if (!strcmp(name, "current"))
sid = __tsec->sid;
+ else if (!strcmp(name, "context"))
+ sid = __tsec->sid;
else if (!strcmp(name, "prev"))
sid = __tsec->osid;
else if (!strcmp(name, "exec"))
@@ -5752,7 +5754,19 @@ static int selinux_getprocattr(struct task_struct *p,
if (!sid)
return 0;
- error = security_sid_to_context(sid, value, &len);
+ if (strcmp(name, "context")) {
+ error = security_sid_to_context(sid, value, &len);
+ } else {
+ char *vp;
+
+ error = security_sid_to_context(sid, &vp, &len);
+ if (!error) {
+ *value = kasprintf(GFP_KERNEL, "selinux='%s'", vp);
+ if (*value == NULL)
+ error = -ENOMEM;
+ }
+ }
+
if (error)
return error;
return len;
@@ -5788,6 +5802,9 @@ static int selinux_setprocattr(const char *name, void *value, size_t size)
else if (!strcmp(name, "current"))
error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
PROCESS__SETCURRENT, NULL);
+ else if (!strcmp(name, "context"))
+ error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
+ PROCESS__SETCURRENT, NULL);
else
error = -EINVAL;
if (error)
@@ -5848,7 +5865,7 @@ static int selinux_setprocattr(const char *name, void *value, size_t size)
tsec->keycreate_sid = sid;
} else if (!strcmp(name, "sockcreate")) {
tsec->sockcreate_sid = sid;
- } else if (!strcmp(name, "current")) {
+ } else if (!strcmp(name, "current") || !strcmp(name, "context")) {
error = -EINVAL;
if (sid == 0)
goto abort_change;
@@ -6294,7 +6311,8 @@ 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;
}
@@ -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(
@@ -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)
@@ -3453,18 +3453,20 @@ 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 if (strcmp(name, "context") == 0) {
+ cp = kasprintf(GFP_KERNEL, "smack='%s'", skp->smk_known);
+ 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);
}
/**
@@ -3492,7 +3494,7 @@ static int smack_setprocattr(const char *name, void *value, size_t size)
if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
return -EINVAL;
- if (strcmp(name, "current") != 0)
+ if (strcmp(name, "current") != 0 && strcmp(name, "context") != 0)
return -EINVAL;
skp = smk_import_entry(value, size);
@@ -4622,7 +4624,8 @@ 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) {
@@ -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;
}
@@ -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) {
Subject: [PATCH 06/11] LSM: general but not extreme module stacking Leverage the infrastructure management of the credential and file security blobs to allow stacking of security modules in all but the most extreme case. Security modules are informed of the location of their data within the blobs at module initialization. Stacking is optional. If stacking is not configured the old limit of one "major" security module applies. If stacking is configured any combination that does not include both SELinux and Smack is allowed. A subdirectory has been added to /proc/.../attr for each of SELinux and AppArmor (Smack introduced such a subdirectory earlier) to disambiguate what data is provided in the proc/.../attr interfaces. An entry "context" is added to /proc/.../attr and to each of the subdirectories. The "context" entry provides process attribute information in the form: lsm-name='lsm-data'[,lsm-name='lsm-data']... Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> --- Documentation/admin-guide/LSM/index.rst | 22 ++++- fs/proc/base.c | 33 ++++++++ include/linux/lsm_hooks.h | 2 +- security/Kconfig | 94 +++++++++++++++++++++ security/apparmor/include/context.h | 10 +++ security/apparmor/lsm.c | 44 ++++++++-- security/security.c | 142 +++++++++++++++++++++++++++++++- security/selinux/hooks.c | 24 +++++- security/selinux/include/objsec.h | 8 ++ security/smack/smack.h | 9 ++ security/smack/smack_lsm.c | 23 +++--- security/tomoyo/common.h | 12 ++- security/tomoyo/tomoyo.c | 3 +- 13 files changed, 398 insertions(+), 28 deletions(-)