Kernel bump from 4.1.3-rt to 4.1.7-rt.
[kvmfornfv.git] / kernel / security / integrity / ima / ima_policy.c
index d1eefb9..3997e20 100644 (file)
@@ -27,6 +27,8 @@
 #define IMA_UID                0x0008
 #define IMA_FOWNER     0x0010
 #define IMA_FSUUID     0x0020
+#define IMA_INMASK     0x0040
+#define IMA_EUID       0x0080
 
 #define UNKNOWN                0
 #define MEASURE                0x0001  /* same as IMA_MEASURE */
@@ -42,6 +44,8 @@ enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
        LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
 };
 
+enum policy_types { ORIGINAL_TCB = 1, DEFAULT_TCB };
+
 struct ima_rule_entry {
        struct list_head list;
        int action;
@@ -70,7 +74,7 @@ struct ima_rule_entry {
  * normal users can easily run the machine out of memory simply building
  * and running executables.
  */
-static struct ima_rule_entry default_rules[] = {
+static struct ima_rule_entry dont_measure_rules[] = {
        {.action = DONT_MEASURE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
        {.action = DONT_MEASURE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
        {.action = DONT_MEASURE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
@@ -79,12 +83,31 @@ static struct ima_rule_entry default_rules[] = {
        {.action = DONT_MEASURE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
        {.action = DONT_MEASURE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
        {.action = DONT_MEASURE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
+       {.action = DONT_MEASURE, .fsmagic = CGROUP_SUPER_MAGIC,
+        .flags = IMA_FSMAGIC},
+       {.action = DONT_MEASURE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC}
+};
+
+static struct ima_rule_entry original_measurement_rules[] = {
        {.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
         .flags = IMA_FUNC | IMA_MASK},
        {.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
         .flags = IMA_FUNC | IMA_MASK},
-       {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ, .uid = GLOBAL_ROOT_UID,
-        .flags = IMA_FUNC | IMA_MASK | IMA_UID},
+       {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
+        .uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_MASK | IMA_UID},
+       {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
+       {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
+};
+
+static struct ima_rule_entry default_measurement_rules[] = {
+       {.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
+        .flags = IMA_FUNC | IMA_MASK},
+       {.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
+        .flags = IMA_FUNC | IMA_MASK},
+       {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
+        .uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_INMASK | IMA_EUID},
+       {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
+        .uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_INMASK | IMA_UID},
        {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
        {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
 };
@@ -99,6 +122,7 @@ static struct ima_rule_entry default_appraise_rules[] = {
        {.action = DONT_APPRAISE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
        {.action = DONT_APPRAISE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
        {.action = DONT_APPRAISE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
+       {.action = DONT_APPRAISE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
        {.action = DONT_APPRAISE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 #ifndef CONFIG_IMA_APPRAISE_SIGNED_INIT
        {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .flags = IMA_FOWNER},
@@ -115,14 +139,29 @@ static struct list_head *ima_rules;
 
 static DEFINE_MUTEX(ima_rules_mutex);
 
-static bool ima_use_tcb __initdata;
+static int ima_policy __initdata;
 static int __init default_measure_policy_setup(char *str)
 {
-       ima_use_tcb = 1;
+       if (ima_policy)
+               return 1;
+
+       ima_policy = ORIGINAL_TCB;
        return 1;
 }
 __setup("ima_tcb", default_measure_policy_setup);
 
+static int __init policy_setup(char *str)
+{
+       if (ima_policy)
+               return 1;
+
+       if (strcmp(str, "tcb") == 0)
+               ima_policy = DEFAULT_TCB;
+
+       return 1;
+}
+__setup("ima_policy=", policy_setup);
+
 static bool ima_use_appraise_tcb __initdata;
 static int __init default_appraise_policy_setup(char *str)
 {
@@ -182,6 +221,9 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
        if ((rule->flags & IMA_MASK) &&
            (rule->mask != mask && func != POST_SETATTR))
                return false;
+       if ((rule->flags & IMA_INMASK) &&
+           (!(rule->mask & mask) && func != POST_SETATTR))
+               return false;
        if ((rule->flags & IMA_FSMAGIC)
            && rule->fsmagic != inode->i_sb->s_magic)
                return false;
@@ -190,6 +232,16 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
                return false;
        if ((rule->flags & IMA_UID) && !uid_eq(rule->uid, cred->uid))
                return false;
+       if (rule->flags & IMA_EUID) {
+               if (has_capability_noaudit(current, CAP_SETUID)) {
+                       if (!uid_eq(rule->uid, cred->euid)
+                           && !uid_eq(rule->uid, cred->suid)
+                           && !uid_eq(rule->uid, cred->uid))
+                               return false;
+               } else if (!uid_eq(rule->uid, cred->euid))
+                       return false;
+       }
+
        if ((rule->flags & IMA_FOWNER) && !uid_eq(rule->fowner, inode->i_uid))
                return false;
        for (i = 0; i < MAX_LSM_RULES; i++) {
@@ -333,21 +385,31 @@ void __init ima_init_policy(void)
 {
        int i, measure_entries, appraise_entries;
 
-       /* if !ima_use_tcb set entries = 0 so we load NO default rules */
-       measure_entries = ima_use_tcb ? ARRAY_SIZE(default_rules) : 0;
+       /* if !ima_policy set entries = 0 so we load NO default rules */
+       measure_entries = ima_policy ? ARRAY_SIZE(dont_measure_rules) : 0;
        appraise_entries = ima_use_appraise_tcb ?
                         ARRAY_SIZE(default_appraise_rules) : 0;
 
-       for (i = 0; i < measure_entries + appraise_entries; i++) {
-               if (i < measure_entries)
-                       list_add_tail(&default_rules[i].list,
-                                     &ima_default_rules);
-               else {
-                       int j = i - measure_entries;
+       for (i = 0; i < measure_entries; i++)
+               list_add_tail(&dont_measure_rules[i].list, &ima_default_rules);
 
-                       list_add_tail(&default_appraise_rules[j].list,
+       switch (ima_policy) {
+       case ORIGINAL_TCB:
+               for (i = 0; i < ARRAY_SIZE(original_measurement_rules); i++)
+                       list_add_tail(&original_measurement_rules[i].list,
                                      &ima_default_rules);
-               }
+               break;
+       case DEFAULT_TCB:
+               for (i = 0; i < ARRAY_SIZE(default_measurement_rules); i++)
+                       list_add_tail(&default_measurement_rules[i].list,
+                                     &ima_default_rules);
+       default:
+               break;
+       }
+
+       for (i = 0; i < appraise_entries; i++) {
+               list_add_tail(&default_appraise_rules[i].list,
+                             &ima_default_rules);
        }
 
        ima_rules = &ima_default_rules;
@@ -373,7 +435,8 @@ enum {
        Opt_audit,
        Opt_obj_user, Opt_obj_role, Opt_obj_type,
        Opt_subj_user, Opt_subj_role, Opt_subj_type,
-       Opt_func, Opt_mask, Opt_fsmagic, Opt_uid, Opt_fowner,
+       Opt_func, Opt_mask, Opt_fsmagic,
+       Opt_uid, Opt_euid, Opt_fowner,
        Opt_appraise_type, Opt_fsuuid, Opt_permit_directio
 };
 
@@ -394,6 +457,7 @@ static match_table_t policy_tokens = {
        {Opt_fsmagic, "fsmagic=%s"},
        {Opt_fsuuid, "fsuuid=%s"},
        {Opt_uid, "uid=%s"},
+       {Opt_euid, "euid=%s"},
        {Opt_fowner, "fowner=%s"},
        {Opt_appraise_type, "appraise_type=%s"},
        {Opt_permit_directio, "permit_directio"},
@@ -435,6 +499,7 @@ static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
 static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 {
        struct audit_buffer *ab;
+       char *from;
        char *p;
        int result = 0;
 
@@ -525,18 +590,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
                        if (entry->mask)
                                result = -EINVAL;
 
-                       if ((strcmp(args[0].from, "MAY_EXEC")) == 0)
+                       from = args[0].from;
+                       if (*from == '^')
+                               from++;
+
+                       if ((strcmp(from, "MAY_EXEC")) == 0)
                                entry->mask = MAY_EXEC;
-                       else if (strcmp(args[0].from, "MAY_WRITE") == 0)
+                       else if (strcmp(from, "MAY_WRITE") == 0)
                                entry->mask = MAY_WRITE;
-                       else if (strcmp(args[0].from, "MAY_READ") == 0)
+                       else if (strcmp(from, "MAY_READ") == 0)
                                entry->mask = MAY_READ;
-                       else if (strcmp(args[0].from, "MAY_APPEND") == 0)
+                       else if (strcmp(from, "MAY_APPEND") == 0)
                                entry->mask = MAY_APPEND;
                        else
                                result = -EINVAL;
                        if (!result)
-                               entry->flags |= IMA_MASK;
+                               entry->flags |= (*args[0].from == '^')
+                                    ? IMA_INMASK : IMA_MASK;
                        break;
                case Opt_fsmagic:
                        ima_log_string(ab, "fsmagic", args[0].from);
@@ -566,6 +636,9 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
                        break;
                case Opt_uid:
                        ima_log_string(ab, "uid", args[0].from);
+               case Opt_euid:
+                       if (token == Opt_euid)
+                               ima_log_string(ab, "euid", args[0].from);
 
                        if (uid_valid(entry->uid)) {
                                result = -EINVAL;
@@ -574,11 +647,14 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 
                        result = kstrtoul(args[0].from, 10, &lnum);
                        if (!result) {
-                               entry->uid = make_kuid(current_user_ns(), (uid_t)lnum);
-                               if (!uid_valid(entry->uid) || (((uid_t)lnum) != lnum))
+                               entry->uid = make_kuid(current_user_ns(),
+                                                      (uid_t) lnum);
+                               if (!uid_valid(entry->uid) ||
+                                   (uid_t)lnum != lnum)
                                        result = -EINVAL;
                                else
-                                       entry->flags |= IMA_UID;
+                                       entry->flags |= (token == Opt_uid)
+                                           ? IMA_UID : IMA_EUID;
                        }
                        break;
                case Opt_fowner: