On 2/18/22 12:09, Mimi Zohar wrote:

On Tue, 2022-02-01 at 15:37 -0500, Stefan Berger wrote:

quoted

Implement ima_free_policy_rules() that is needed when an ima_namespace
is freed.

Signed-off-by: Stefan Berger <stefanb@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 aea8fb8d2854..8c757223d549 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h

@@ -329,6 +329,7 @@ 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 2dcc5a8c585a..fe3dce8fb939 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c

@@ -1889,6 +1889,20 @@ 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);
+	}
+}
+

The first time a policy is loaded, the policy rules pivot
from ima_default_rules to the custom rules.  When this happens, the
architecture specific policy rules are freed.  Here too, if a custom
policy isn't already loaded, the architecture specific rules stored as
an array need to be freed.  Refer to the comment in
ima_update_policy().

Right. So here's how it's done (before arch_policy_entry was moved into 
ima_namespace).

         /*
          * IMA architecture specific policy rules are specified
          * as strings and converted to an array of ima_entry_rules
          * on boot.  After loading a custom policy, free the
          * architecture specific rules stored as an array.
          */
         kfree(arch_policy_entry);


So, I now added kfree(ns->arch_policy_entry).

Thanks.

    Stefan

quoted

  #define __ima_hook_stringify(func, str)	(#func),
  
  const char *const func_tokens[] = {