1 files changed, 155 insertions, 54 deletions

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 1a9583008aae..c7dacd2eab7a 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -24,22 +24,29 @@
 #define IMA_MASK        0x0002
 #define IMA_FSMAGIC     0x0004
 #define IMA_UID         0x0008
+#define IMA_FOWNER      0x0010
 
-enum ima_action { UNKNOWN = -1, DONT_MEASURE = 0, MEASURE };
+#define UNKNOWN         0
+#define MEASURE         0x0001  /* same as IMA_MEASURE */
+#define DONT_MEASURE    0x0002
+#define APPRAISE        0x0004  /* same as IMA_APPRAISE */
+#define DONT_APPRAISE   0x0008
+#define AUDIT           0x0040
 
 #define MAX_LSM_RULES 6
 enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
         LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
 };
 
-struct ima_measure_rule_entry {
+struct ima_rule_entry {
         struct list_head list;
-        enum ima_action action;
+        int action;
         unsigned int flags;
         enum ima_hooks func;
         int mask;
         unsigned long fsmagic;
-        uid_t uid;
+        kuid_t uid;
+        kuid_t fowner;
         struct {
                 void *rule;     /* LSM file metadata specific */
                 int type;       /* audit type */
@@ -48,7 +55,7 @@ struct ima_measure_rule_entry {
 
 /*
  * Without LSM specific knowledge, the default policy can only be
- * written in terms of .action, .func, .mask, .fsmagic, and .uid
+ * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
  */
 
 /*
@@ -57,7 +64,7 @@ struct ima_measure_rule_entry {
  * normal users can easily run the machine out of memory simply building
  * and running executables.
  */
-static struct ima_measure_rule_entry default_rules[] = {
+static struct ima_rule_entry default_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},
@@ -71,23 +78,45 @@ static struct ima_measure_rule_entry default_rules[] = {
          .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 = 0,
+        {.action = MEASURE,.func = FILE_CHECK,.mask = MAY_READ,.uid = GLOBAL_ROOT_UID,
          .flags = IMA_FUNC | IMA_MASK | IMA_UID},
 };
 
-static LIST_HEAD(measure_default_rules);
-static LIST_HEAD(measure_policy_rules);
-static struct list_head *ima_measure;
+static struct ima_rule_entry default_appraise_rules[] = {
+        {.action = DONT_APPRAISE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+        {.action = DONT_APPRAISE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
+        {.action = DONT_APPRAISE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
+        {.action = DONT_APPRAISE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
+        {.action = DONT_APPRAISE,.fsmagic = RAMFS_MAGIC,.flags = IMA_FSMAGIC},
+        {.action = DONT_APPRAISE,.fsmagic = DEVPTS_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+        {.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 = CGROUP_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+        {.action = APPRAISE,.fowner = GLOBAL_ROOT_UID,.flags = IMA_FOWNER},
+};
+
+static LIST_HEAD(ima_default_rules);
+static LIST_HEAD(ima_policy_rules);
+static struct list_head *ima_rules;
 
-static DEFINE_MUTEX(ima_measure_mutex);
+static DEFINE_MUTEX(ima_rules_mutex);
 
 static bool ima_use_tcb __initdata;
-static int __init default_policy_setup(char *str)
+static int __init default_measure_policy_setup(char *str)
 {
         ima_use_tcb = 1;
         return 1;
 }
-__setup("ima_tcb", default_policy_setup);
+__setup("ima_tcb", default_measure_policy_setup);
+
+static bool ima_use_appraise_tcb __initdata;
+static int __init default_appraise_policy_setup(char *str)
+{
+        ima_use_appraise_tcb = 1;
+        return 1;
+}
+__setup("ima_appraise_tcb", default_appraise_policy_setup);
 
 /**
  * ima_match_rules - determine whether an inode matches the measure rule.
@@ -98,7 +127,7 @@ __setup("ima_tcb", default_policy_setup);
  *
  * Returns true on rule match, false on failure.
  */
-static bool ima_match_rules(struct ima_measure_rule_entry *rule,
+static bool ima_match_rules(struct ima_rule_entry *rule,
                             struct inode *inode, enum ima_hooks func, int mask)
 {
         struct task_struct *tsk = current;
@@ -112,7 +141,9 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule,
         if ((rule->flags & IMA_FSMAGIC)
             && rule->fsmagic != inode->i_sb->s_magic)
                 return false;
-        if ((rule->flags & IMA_UID) && rule->uid != cred->uid)
+        if ((rule->flags & IMA_UID) && !uid_eq(rule->uid, cred->uid))
+                return false;
+        if ((rule->flags & IMA_FOWNER) && !uid_eq(rule->fowner, inode->i_uid))
                 return false;
         for (i = 0; i < MAX_LSM_RULES; i++) {
                 int rc = 0;
@@ -163,39 +194,61 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule,
  * as elements in the list are never deleted, nor does the list
  * change.)
  */
-int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask)
+int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
+                     int flags)
 {
-        struct ima_measure_rule_entry *entry;
+        struct ima_rule_entry *entry;
+        int action = 0, actmask = flags | (flags << 1);
+
+        list_for_each_entry(entry, ima_rules, list) {
+
+                if (!(entry->action & actmask))
+                        continue;
+
+                if (!ima_match_rules(entry, inode, func, mask))
+                        continue;
 
-        list_for_each_entry(entry, ima_measure, list) {
-                bool rc;
+                action |= entry->action & IMA_DO_MASK;
+                if (entry->action & IMA_DO_MASK)
+                        actmask &= ~(entry->action | entry->action << 1);
+                else
+                        actmask &= ~(entry->action | entry->action >> 1);
 
-                rc = ima_match_rules(entry, inode, func, mask);
-                if (rc)
-                        return entry->action;
+                if (!actmask)
+                        break;
         }
-        return 0;
+
+        return action;
 }
 
 /**
  * ima_init_policy - initialize the default measure rules.
  *
- * ima_measure points to either the measure_default_rules or the
- * the new measure_policy_rules.
+ * ima_rules points to either the ima_default_rules or the
+ * the new ima_policy_rules.
  */
 void __init ima_init_policy(void)
 {
-        int i, entries;
+        int i, measure_entries, appraise_entries;
 
         /* if !ima_use_tcb set entries = 0 so we load NO default rules */
-        if (ima_use_tcb)
-                entries = ARRAY_SIZE(default_rules);
-        else
-                entries = 0;
-
-        for (i = 0; i < entries; i++)
-                list_add_tail(&default_rules[i].list, &measure_default_rules);
-        ima_measure = &measure_default_rules;
+        measure_entries = ima_use_tcb ? ARRAY_SIZE(default_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;
+
+                        list_add_tail(&default_appraise_rules[j].list,
+                                      &ima_default_rules);
+                }
+        }
+
+        ima_rules = &ima_default_rules;
 }
 
 /**
@@ -212,8 +265,8 @@ void ima_update_policy(void)
         int result = 1;
         int audit_info = 0;
 
-        if (ima_measure == &measure_default_rules) {
-                ima_measure = &measure_policy_rules;
+        if (ima_rules == &ima_default_rules) {
+                ima_rules = &ima_policy_rules;
                 cause = "complete";
                 result = 0;
         }
@@ -224,14 +277,19 @@ void ima_update_policy(void)
 enum {
         Opt_err = -1,
         Opt_measure = 1, Opt_dont_measure,
+        Opt_appraise, Opt_dont_appraise,
+        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_func, Opt_mask, Opt_fsmagic, Opt_uid, Opt_fowner
 };
 
 static match_table_t policy_tokens = {
         {Opt_measure, "measure"},
         {Opt_dont_measure, "dont_measure"},
+        {Opt_appraise, "appraise"},
+        {Opt_dont_appraise, "dont_appraise"},
+        {Opt_audit, "audit"},
         {Opt_obj_user, "obj_user=%s"},
         {Opt_obj_role, "obj_role=%s"},
         {Opt_obj_type, "obj_type=%s"},
@@ -242,10 +300,11 @@ static match_table_t policy_tokens = {
         {Opt_mask, "mask=%s"},
         {Opt_fsmagic, "fsmagic=%s"},
         {Opt_uid, "uid=%s"},
+        {Opt_fowner, "fowner=%s"},
         {Opt_err, NULL}
 };
 
-static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry,
+static int ima_lsm_rule_init(struct ima_rule_entry *entry,
                              char *args, int lsm_rule, int audit_type)
 {
         int result;
@@ -269,7 +328,7 @@ static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
         audit_log_format(ab, " ");
 }
 
-static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
+static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 {
         struct audit_buffer *ab;
         char *p;
@@ -277,7 +336,8 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
 
         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
 
-        entry->uid = -1;
+        entry->uid = INVALID_UID;
+        entry->fowner = INVALID_UID;
         entry->action = UNKNOWN;
         while ((p = strsep(&rule, " \t")) != NULL) {
                 substring_t args[MAX_OPT_ARGS];
@@ -306,11 +366,35 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
 
                         entry->action = DONT_MEASURE;
                         break;
+                case Opt_appraise:
+                        ima_log_string(ab, "action", "appraise");
+
+                        if (entry->action != UNKNOWN)
+                                result = -EINVAL;
+
+                        entry->action = APPRAISE;
+                        break;
+                case Opt_dont_appraise:
+                        ima_log_string(ab, "action", "dont_appraise");
+
+                        if (entry->action != UNKNOWN)
+                                result = -EINVAL;
+
+                        entry->action = DONT_APPRAISE;
+                        break;
+                case Opt_audit:
+                        ima_log_string(ab, "action", "audit");
+
+                        if (entry->action != UNKNOWN)
+                                result = -EINVAL;
+
+                        entry->action = AUDIT;
+                        break;
                 case Opt_func:
                         ima_log_string(ab, "func", args[0].from);
 
                         if (entry->func)
-                                result  = -EINVAL;
+                                result = -EINVAL;
 
                         if (strcmp(args[0].from, "FILE_CHECK") == 0)
                                 entry->func = FILE_CHECK;
@@ -361,20 +445,37 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
                 case Opt_uid:
                         ima_log_string(ab, "uid", args[0].from);
 
-                        if (entry->uid != -1) {
+                        if (uid_valid(entry->uid)) {
                                 result = -EINVAL;
                                 break;
                         }
 
                         result = strict_strtoul(args[0].from, 10, &lnum);
                         if (!result) {
-                                entry->uid = (uid_t) lnum;
-                                if (entry->uid != 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;
                         }
                         break;
+                case Opt_fowner:
+                        ima_log_string(ab, "fowner", args[0].from);
+
+                        if (uid_valid(entry->fowner)) {
+                                result = -EINVAL;
+                                break;
+                        }
+
+                        result = strict_strtoul(args[0].from, 10, &lnum);
+                        if (!result) {
+                                entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum);
+                                if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum))
+                                        result = -EINVAL;
+                                else
+                                        entry->flags |= IMA_FOWNER;
+                        }
+                        break;
                 case Opt_obj_user:
                         ima_log_string(ab, "obj_user", args[0].from);
                         result = ima_lsm_rule_init(entry, args[0].from,
@@ -426,7 +527,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
 }
 
 /**
- * ima_parse_add_rule - add a rule to measure_policy_rules
+ * ima_parse_add_rule - add a rule to ima_policy_rules
  * @rule - ima measurement policy rule
  *
  * Uses a mutex to protect the policy list from multiple concurrent writers.
@@ -436,12 +537,12 @@ ssize_t ima_parse_add_rule(char *rule)
 {
         const char *op = "update_policy";
         char *p;
-        struct ima_measure_rule_entry *entry;
+        struct ima_rule_entry *entry;
         ssize_t result, len;
         int audit_info = 0;
 
         /* Prevent installed policy from changing */
-        if (ima_measure != &measure_default_rules) {
+        if (ima_rules != &ima_default_rules) {
                 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
                                     NULL, op, "already exists",
                                     -EACCES, audit_info);
@@ -474,9 +575,9 @@ ssize_t ima_parse_add_rule(char *rule)
                 return result;
         }
 
-        mutex_lock(&ima_measure_mutex);
-        list_add_tail(&entry->list, &measure_policy_rules);
-        mutex_unlock(&ima_measure_mutex);
+        mutex_lock(&ima_rules_mutex);
+        list_add_tail(&entry->list, &ima_policy_rules);
+        mutex_unlock(&ima_rules_mutex);
 
         return len;
 }
@@ -484,12 +585,12 @@ ssize_t ima_parse_add_rule(char *rule)
 /* ima_delete_rules called to cleanup invalid policy */
 void ima_delete_rules(void)
 {
-        struct ima_measure_rule_entry *entry, *tmp;
+        struct ima_rule_entry *entry, *tmp;
 
-        mutex_lock(&ima_measure_mutex);
-        list_for_each_entry_safe(entry, tmp, &measure_policy_rules, list) {
+        mutex_lock(&ima_rules_mutex);
+        list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) {
                 list_del(&entry->list);
                 kfree(entry);
         }
-        mutex_unlock(&ima_measure_mutex);
+        mutex_unlock(&ima_rules_mutex);
 }