Hello Mimi,
Sorry for the late response. I was on vacation last week.

On 2020-12-24 5:06 a.m., Mimi Zohar wrote:

On Sat, 2020-12-12 at 10:02 -0800, Tushar Sugandhi wrote:

quoted

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 68956e884403..e76ef4bfd0f4 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c

@@ -786,13 +786,13 @@ int ima_post_load_data(char *buf, loff_t size,
   * @eventname: event name to be used for the buffer entry.
   * @func: IMA hook
   * @pcr: pcr to extend the measurement
- * @keyring: keyring name to determine the action to be performed
+ * @func_data: private data specific to @func, can be NULL.

This can be simplified to "func specific data, may be NULL".   Please
update in all places.

Ok, will do.

quoted

   *
   * Based on policy, the buffer is measured into the ima log.
   */
  void process_buffer_measurement(struct inode *inode, const void *buf, int size,
  				const char *eventname, enum ima_hooks func,
-				int pcr, const char *keyring)
+				int pcr, const char *func_data)
  {
  	int ret = 0;
  	const char *audit_cause = "ENOMEM";

@@ -831,7 +831,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size,
  	if (func) {
  		security_task_getsecid(current, &secid);
  		action = ima_get_action(inode, current_cred(), secid, 0, func,
-					&pcr, &template, keyring);
+					&pcr, &template, func_data);
  		if (!(action & IMA_MEASURE))
  			return;
  	}

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 823a0c1379cb..a09d1a41a290 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c

@@ -453,30 +453,41 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
  }
  
  /**
- * ima_match_keyring - determine whether the keyring matches the measure rule
- * @rule: a pointer to a rule
- * @keyring: name of the keyring to match against the measure rule
+ * ima_match_rule_data - determine whether the given func_data matches
+ *			 the measure rule data

After the function_name is a brief description of the function, which
should not span multiple lines.  Refer to Documentation/doc-
guide/kernel-doc.rst for details.

Please trim the function description to:
determine whether func_data matches the policy rule

Thanks, will do.

quoted

+ * @rule: IMA policy rule

This patch should be limited to renaming "keyring" to "func_data".   It
shouldn't make other changes, even simple ones like this.

Agreed. I will revert the rule description to the old one.

quoted

+ * @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;
+	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;
  		}

@@ -493,20 +504,20 @@ static bool ima_match_keyring(struct ima_rule_entry *rule,
   * @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: private data specific to @func, can be NULL.

Update as previously suggested.

Yes.

quoted

   *
   * 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)
+			    const char *func_data)
  {
  	int i;
  
  	if (func == KEY_CHECK) {
  		return (rule->flags & IMA_FUNC) && (rule->func == func) &&
-		       ima_match_keyring(rule, keyring, cred);
+			ima_match_rule_data(rule, func_data, cred);
  	}
  	if ((rule->flags & IMA_FUNC) &&
  	    (rule->func != func && func != POST_SETATTR))

@@ -610,8 +621,7 @@ 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: private data specific to @func, can be NULL.

And again here.

Yes.

thanks,

Mimi

Thanks,
Tushar