/* Maximum number of letters for an LSM name string */
#define SECURITY_NAME_MAX 10
+/* How many LSMs were built into the kernel? */
+#define LSM_COUNT (__end_lsm_info - __start_lsm_info)
+
struct security_hook_heads security_hook_heads __lsm_ro_after_init;
static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain);
static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
CONFIG_DEFAULT_SECURITY;
+static __initconst const char * const builtin_lsm_order = CONFIG_LSM;
+
+/* Ordered list of LSMs to initialize. */
+static __initdata struct lsm_info **ordered_lsms;
+
static __initdata bool debug;
#define init_debug(...) \
do { \
pr_info(__VA_ARGS__); \
} while (0)
-static void __init major_lsm_init(void)
+static bool __init is_enabled(struct lsm_info *lsm)
{
- struct lsm_info *lsm;
- int ret;
+ if (!lsm->enabled || *lsm->enabled)
+ return true;
+
+ return false;
+}
+
+/* Mark an LSM's enabled flag. */
+static int lsm_enabled_true __initdata = 1;
+static int lsm_enabled_false __initdata = 0;
+static void __init set_enabled(struct lsm_info *lsm, bool enabled)
+{
+ /*
+ * When an LSM hasn't configured an enable variable, we can use
+ * a hard-coded location for storing the default enabled state.
+ */
+ if (!lsm->enabled) {
+ if (enabled)
+ lsm->enabled = &lsm_enabled_true;
+ else
+ lsm->enabled = &lsm_enabled_false;
+ } else if (lsm->enabled == &lsm_enabled_true) {
+ if (!enabled)
+ lsm->enabled = &lsm_enabled_false;
+ } else if (lsm->enabled == &lsm_enabled_false) {
+ if (enabled)
+ lsm->enabled = &lsm_enabled_true;
+ } else {
+ *lsm->enabled = enabled;
+ }
+}
+
+/* Is an LSM already listed in the ordered LSMs list? */
+static bool __init exists_ordered_lsm(struct lsm_info *lsm)
+{
+ struct lsm_info **check;
+
+ for (check = ordered_lsms; *check; check++)
+ if (*check == lsm)
+ return true;
+
+ return false;
+}
+
+/* Append an LSM to the list of ordered LSMs to initialize. */
+static int last_lsm __initdata;
+static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from)
+{
+ /* Ignore duplicate selections. */
+ if (exists_ordered_lsm(lsm))
+ return;
+
+ if (WARN(last_lsm == LSM_COUNT, "%s: out of LSM slots!?\n", from))
+ return;
+
+ ordered_lsms[last_lsm++] = lsm;
+ init_debug("%s ordering: %s (%sabled)\n", from, lsm->name,
+ is_enabled(lsm) ? "en" : "dis");
+}
+
+/* Is an LSM allowed to be initialized? */
+static bool __init lsm_allowed(struct lsm_info *lsm)
+{
+ /* Skip if the LSM is disabled. */
+ if (!is_enabled(lsm))
+ 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 initialized. */
+static void __init maybe_initialize_lsm(struct lsm_info *lsm)
+{
+ int enabled = lsm_allowed(lsm);
+
+ /* Record enablement (to handle any following exclusive LSMs). */
+ set_enabled(lsm, enabled);
+
+ /* If selected, initialize the LSM. */
+ if (enabled) {
+ int ret;
- for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
init_debug("initializing %s\n", lsm->name);
ret = lsm->init();
WARN(ret, "%s failed to initialize: %d\n", lsm->name, ret);
}
}
+/* Populate ordered LSMs list from comma-separated LSM name list. */
+static void __init ordered_lsm_parse(const char *order, const char *origin)
+{
+ struct lsm_info *lsm;
+ char *sep, *name, *next;
+
+ sep = kstrdup(order, GFP_KERNEL);
+ next = sep;
+ /* Walk the list, looking for matching LSMs. */
+ while ((name = strsep(&next, ",")) != NULL) {
+ bool found = false;
+
+ for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
+ if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) == 0 &&
+ strcmp(lsm->name, name) == 0) {
+ append_ordered_lsm(lsm, origin);
+ found = true;
+ }
+ }
+
+ if (!found)
+ init_debug("%s ignored: %s\n", origin, name);
+ }
+ kfree(sep);
+}
+
+static void __init ordered_lsm_init(void)
+{
+ struct lsm_info **lsm;
+
+ ordered_lsms = kcalloc(LSM_COUNT + 1, sizeof(*ordered_lsms),
+ GFP_KERNEL);
+
+ ordered_lsm_parse(builtin_lsm_order, "builtin");
+
+ for (lsm = ordered_lsms; *lsm; lsm++)
+ maybe_initialize_lsm(*lsm);
+
+ kfree(ordered_lsms);
+}
+
+static void __init major_lsm_init(void)
+{
+ struct lsm_info *lsm;
+
+ for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
+ if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) == 0)
+ continue;
+
+ maybe_initialize_lsm(lsm);
+ }
+}
+
/**
* security_init - initializes the security framework
*
yama_add_hooks();
loadpin_add_hooks();
+ /* Load LSMs in specified order. */
+ ordered_lsm_init();
+
/*
* Load all the remaining security modules.
*/
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
call_void_hook(sb_free_security, sb);
}
-int security_sb_copy_data(char *orig, char *copy)
+void security_free_mnt_opts(void **mnt_opts)
+{
+ if (!*mnt_opts)
+ return;
+ call_void_hook(sb_free_mnt_opts, *mnt_opts);
+ *mnt_opts = NULL;
+}
+EXPORT_SYMBOL(security_free_mnt_opts);
+
+int security_sb_eat_lsm_opts(char *options, void **mnt_opts)
{
- return call_int_hook(sb_copy_data, 0, orig, copy);
+ return call_int_hook(sb_eat_lsm_opts, 0, options, mnt_opts);
}
-EXPORT_SYMBOL(security_sb_copy_data);
+EXPORT_SYMBOL(security_sb_eat_lsm_opts);
-int security_sb_remount(struct super_block *sb, void *data)
+int security_sb_remount(struct super_block *sb,
+ void *mnt_opts)
{
- return call_int_hook(sb_remount, 0, sb, data);
+ return call_int_hook(sb_remount, 0, sb, mnt_opts);
}
+EXPORT_SYMBOL(security_sb_remount);
-int security_sb_kern_mount(struct super_block *sb, int flags, void *data)
+int security_sb_kern_mount(struct super_block *sb)
{
- return call_int_hook(sb_kern_mount, 0, sb, flags, data);
+ return call_int_hook(sb_kern_mount, 0, sb);
}
int security_sb_show_options(struct seq_file *m, struct super_block *sb)
}
int security_sb_set_mnt_opts(struct super_block *sb,
- struct security_mnt_opts *opts,
+ void *mnt_opts,
unsigned long kern_flags,
unsigned long *set_kern_flags)
{
return call_int_hook(sb_set_mnt_opts,
- opts->num_mnt_opts ? -EOPNOTSUPP : 0, sb,
- opts, kern_flags, set_kern_flags);
+ mnt_opts ? -EOPNOTSUPP : 0, sb,
+ mnt_opts, kern_flags, set_kern_flags);
}
EXPORT_SYMBOL(security_sb_set_mnt_opts);
}
EXPORT_SYMBOL(security_sb_clone_mnt_opts);
-int security_sb_parse_opts_str(char *options, struct security_mnt_opts *opts)
+int security_add_mnt_opt(const char *option, const char *val, int len,
+ void **mnt_opts)
{
- return call_int_hook(sb_parse_opts_str, 0, options, opts);
+ return call_int_hook(sb_add_mnt_opt, -EINVAL,
+ option, val, len, mnt_opts);
}
-EXPORT_SYMBOL(security_sb_parse_opts_str);
+EXPORT_SYMBOL(security_add_mnt_opt);
int security_inode_alloc(struct inode *inode)
{
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