1 files changed, 105 insertions, 28 deletions

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 823a0c1379cb..4f8cb155e4fd 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -34,6 +34,7 @@
 #define IMA_PCR		0x0100
 #define IMA_FSNAME	0x0200
 #define IMA_KEYRINGS	0x0400
+#define IMA_LABEL	0x0800
 
 #define UNKNOWN		0
 #define MEASURE		0x0001	/* same as IMA_MEASURE */
@@ -85,6 +86,7 @@ struct ima_rule_entry {
 	} lsm[MAX_LSM_RULES];
 	char *fsname;
 	struct ima_rule_opt_list *keyrings; /* Measure keys added to these keyrings */
+	struct ima_rule_opt_list *label; /* Measure data grouped under this label */
 	struct ima_template_desc *template;
 };
 
@@ -204,6 +206,10 @@ static struct ima_rule_entry secure_boot_rules[] __ro_after_init = {
 	 .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 };
 
+static struct ima_rule_entry critical_data_rules[] __ro_after_init = {
+	{.action = MEASURE, .func = CRITICAL_DATA, .flags = IMA_FUNC},
+};
+
 /* An array of architecture specific rules */
 static struct ima_rule_entry *arch_policy_entry __ro_after_init;
 
@@ -226,6 +232,7 @@ __setup("ima_tcb", default_measure_policy_setup);
 
 static bool ima_use_appraise_tcb __initdata;
 static bool ima_use_secure_boot __initdata;
+static bool ima_use_critical_data __initdata;
 static bool ima_fail_unverifiable_sigs __ro_after_init;
 static int __init policy_setup(char *str)
 {
@@ -240,6 +247,8 @@ static int __init policy_setup(char *str)
 			ima_use_appraise_tcb = true;
 		else if (strcmp(p, "secure_boot") == 0)
 			ima_use_secure_boot = true;
+		else if (strcmp(p, "critical_data") == 0)
+			ima_use_critical_data = true;
 		else if (strcmp(p, "fail_securely") == 0)
 			ima_fail_unverifiable_sigs = true;
 		else
@@ -453,30 +462,46 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
 }
 
 /**
- * ima_match_keyring - determine whether the keyring matches the measure rule
+ * ima_match_rule_data - determine whether func_data matches the policy rule
  * @rule: a pointer to a rule
- * @keyring: name of the keyring to match against the measure rule
+ * @func_data: data to match against the measure rule data
  * @cred: a pointer to a credentials structure for user validation
  *
- * Returns true if keyring matches one in the rule, false otherwise.
+ * Returns true if func_data matches one in the rule, false otherwise.
  */
-static bool ima_match_keyring(struct ima_rule_entry *rule,
-			      const char *keyring, const struct cred *cred)
+static bool ima_match_rule_data(struct ima_rule_entry *rule,
+				const char *func_data,
+				const struct cred *cred)
 {
+	const struct ima_rule_opt_list *opt_list = NULL;
 	bool matched = false;
 	size_t i;
 
 	if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid))
 		return false;
 
-	if (!rule->keyrings)
-		return true;
+	switch (rule->func) {
+	case KEY_CHECK:
+		if (!rule->keyrings)
+			return true;
+
+		opt_list = rule->keyrings;
+		break;
+	case CRITICAL_DATA:
+		if (!rule->label)
+			return true;
+
+		opt_list = rule->label;
+		break;
+	default:
+		return false;
+	}
 
-	if (!keyring)
+	if (!func_data)
 		return false;
 
-	for (i = 0; i < rule->keyrings->count; i++) {
-		if (!strcmp(rule->keyrings->items[i], keyring)) {
+	for (i = 0; i < opt_list->count; i++) {
+		if (!strcmp(opt_list->items[i], func_data)) {
 			matched = true;
 			break;
 		}
@@ -488,29 +513,37 @@ static bool ima_match_keyring(struct ima_rule_entry *rule,
 /**
  * ima_match_rules - determine whether an inode matches the policy rule.
  * @rule: a pointer to a rule
+ * @mnt_userns:	user namespace of the mount the inode was found from
  * @inode: a pointer to an inode
  * @cred: a pointer to a credentials structure for user validation
  * @secid: the secid of the task to be validated
  * @func: LIM hook identifier
  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
- * @keyring: keyring name to check in policy for KEY_CHECK func
+ * @func_data: func specific data, may be NULL
  *
  * Returns true on rule match, false on failure.
  */
-static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
-			    const struct cred *cred, u32 secid,
-			    enum ima_hooks func, int mask,
-			    const char *keyring)
+static bool ima_match_rules(struct ima_rule_entry *rule,
+			    struct user_namespace *mnt_userns,
+			    struct inode *inode, const struct cred *cred,
+			    u32 secid, enum ima_hooks func, int mask,
+			    const char *func_data)
 {
 	int i;
 
-	if (func == KEY_CHECK) {
-		return (rule->flags & IMA_FUNC) && (rule->func == func) &&
-		       ima_match_keyring(rule, keyring, cred);
-	}
 	if ((rule->flags & IMA_FUNC) &&
 	    (rule->func != func && func != POST_SETATTR))
 		return false;
+
+	switch (func) {
+	case KEY_CHECK:
+	case CRITICAL_DATA:
+		return ((rule->func == func) &&
+			ima_match_rule_data(rule, func_data, cred));
+	default:
+		break;
+	}
+
 	if ((rule->flags & IMA_MASK) &&
 	    (rule->mask != mask && func != POST_SETATTR))
 		return false;
@@ -539,7 +572,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 	}
 
 	if ((rule->flags & IMA_FOWNER) &&
-	    !rule->fowner_op(inode->i_uid, rule->fowner))
+	    !rule->fowner_op(i_uid_into_mnt(mnt_userns, inode), rule->fowner))
 		return false;
 	for (i = 0; i < MAX_LSM_RULES; i++) {
 		int rc = 0;
@@ -602,6 +635,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
 
 /**
  * ima_match_policy - decision based on LSM and other conditions
+ * @mnt_userns:	user namespace of the mount the inode was found from
  * @inode: pointer to an inode for which the policy decision is being made
  * @cred: pointer to a credentials structure for which the policy decision is
  *        being made
@@ -610,8 +644,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
  * @pcr: set the pcr to extend
  * @template_desc: the template that should be used for this rule
- * @keyring: the keyring name, if given, to be used to check in the policy.
- *           keyring can be NULL if func is anything other than KEY_CHECK.
+ * @func_data: func specific data, may be NULL
  *
  * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
  * conditions.
@@ -620,10 +653,11 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  * list when walking it.  Reads are many orders of magnitude more numerous
  * than writes so ima_match_policy() is classical RCU candidate.
  */
-int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
-		     enum ima_hooks func, int mask, int flags, int *pcr,
+int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
+		     const struct cred *cred, u32 secid, enum ima_hooks func,
+		     int mask, int flags, int *pcr,
 		     struct ima_template_desc **template_desc,
-		     const char *keyring)
+		     const char *func_data)
 {
 	struct ima_rule_entry *entry;
 	int action = 0, actmask = flags | (flags << 1);
@@ -637,8 +671,8 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
 		if (!(entry->action & actmask))
 			continue;
 
-		if (!ima_match_rules(entry, inode, cred, secid, func, mask,
-				     keyring))
+		if (!ima_match_rules(entry, mnt_userns, inode, cred, secid,
+				     func, mask, func_data))
 			continue;
 
 		action |= entry->flags & IMA_ACTION_FLAGS;
@@ -848,6 +882,11 @@ void __init ima_init_policy(void)
 			  ARRAY_SIZE(default_appraise_rules),
 			  IMA_DEFAULT_POLICY);
 
+	if (ima_use_critical_data)
+		add_rules(critical_data_rules,
+			  ARRAY_SIZE(critical_data_rules),
+			  IMA_DEFAULT_POLICY);
+
 	ima_update_policy_flag();
 }
 
@@ -907,7 +946,7 @@ enum {
 	Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
 	Opt_appraise_type, Opt_appraise_flag,
 	Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
-	Opt_err
+	Opt_label, Opt_err
 };
 
 static const match_table_t policy_tokens = {
@@ -944,6 +983,7 @@ static const match_table_t policy_tokens = {
 	{Opt_pcr, "pcr=%s"},
 	{Opt_template, "template=%s"},
 	{Opt_keyrings, "keyrings=%s"},
+	{Opt_label, "label=%s"},
 	{Opt_err, NULL}
 };
 
@@ -1107,6 +1147,18 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
 			return false;
 
 		break;
+	case CRITICAL_DATA:
+		if (entry->action & ~(MEASURE | DONT_MEASURE))
+			return false;
+
+		if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR |
+				     IMA_LABEL))
+			return false;
+
+		if (ima_rule_contains_lsm_cond(entry))
+			return false;
+
+		break;
 	default:
 		return false;
 	}
@@ -1238,6 +1290,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 			else if (IS_ENABLED(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) &&
 				 strcmp(args[0].from, "KEY_CHECK") == 0)
 				entry->func = KEY_CHECK;
+			else if (strcmp(args[0].from, "CRITICAL_DATA") == 0)
+				entry->func = CRITICAL_DATA;
 			else
 				result = -EINVAL;
 			if (!result)
@@ -1308,6 +1362,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 
 			entry->flags |= IMA_KEYRINGS;
 			break;
+		case Opt_label:
+			ima_log_string(ab, "label", args[0].from);
+
+			if (entry->label) {
+				result = -EINVAL;
+				break;
+			}
+
+			entry->label = ima_alloc_rule_opt_list(args);
+			if (IS_ERR(entry->label)) {
+				result = PTR_ERR(entry->label);
+				entry->label = NULL;
+				break;
+			}
+
+			entry->flags |= IMA_LABEL;
+			break;
 		case Opt_fsuuid:
 			ima_log_string(ab, "fsuuid", args[0].from);
 
@@ -1688,6 +1759,12 @@ int ima_policy_show(struct seq_file *m, void *v)
 		seq_puts(m, " ");
 	}
 
+	if (entry->flags & IMA_LABEL) {
+		seq_puts(m, "label=");
+		ima_show_rule_opt_list(m, entry->label);
+		seq_puts(m, " ");
+	}
+
 	if (entry->flags & IMA_PCR) {
 		snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr);
 		seq_printf(m, pt(Opt_pcr), tbuf);