[PATCH v11 16/27] ima: Implement ima_free_policy_rules() for freeing of an ima_namespace

[Stefan Berger]

Implement ima_free_policy_rules() to free the current custom IMA policy's
rules. This function will be called when an ima_namespace is freed.

Signed-off-by: Stefan Berger <stefanb at linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar at linux.ibm.com>

---
v10:
  - Not calling ima_delete_rules() anymore
  - Move access check from ima_delete_rules into very last patch

 v9:
  - Only reset temp_ima_appraise when using init_ima_ns.
---
 security/integrity/ima/ima.h        |  1 +
 security/integrity/ima/ima_policy.c | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 2775a6d89e6d..054b8f67be04 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -333,6 +333,7 @@ void ima_update_policy_flags(struct ima_namespace *ns);
 ssize_t ima_parse_add_rule(struct ima_namespace *ns, char *rule);
 void ima_delete_rules(struct ima_namespace *ns);
 int ima_check_policy(struct ima_namespace *ns);
+void ima_free_policy_rules(struct ima_namespace *ns);
 void *ima_policy_start(struct seq_file *m, loff_t *pos);
 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
 void ima_policy_stop(struct seq_file *m, void *v);
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index c30e1f4490ae..50c7bdec5109 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -1906,6 +1906,20 @@ void ima_delete_rules(struct ima_namespace *ns)
 	}
 }
 
+/**
+ * ima_free_policy_rules - free all policy rules
+ * @ns: IMA namespace that has the policy
+ */
+void ima_free_policy_rules(struct ima_namespace *ns)
+{
+	struct ima_rule_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &ns->ima_policy_rules, list) {
+		list_del(&entry->list);
+		ima_free_rule(entry);
+	}
+}
+
 #define __ima_hook_stringify(func, str)	(#func),
 
 const char *const func_tokens[] = {
-- 
2.31.1