launch/policy: deallocate unused records during import

When records are imported, but never linked to any policy list, we
currently leak the records. Fix this and properly deallocate the records
in those cases.

Note that this only happens when invalid uids/gids are specified, which
is not common for production systems.

Reported-by: Evgeny Vereshchagin <[email protected]>
Reported-by: Frantisek Sumsal <[email protected]>
Signed-off-by: David Rheinsberg <[email protected]>

src/launch/policy.c

@@ -405,7 +405,8 @@ static int policy_import_own(Policy *policy, ConfigNode *cnode) {
                 c_list_link_tail(&policy->default_entries.own_list, &record->link);
         }
 
-        record = NULL;
+        if (c_list_is_linked(&record->link))
+                record = NULL;
         return 0;
 }
 
@@ -497,7 +498,8 @@ static int policy_import_send(Policy *policy, ConfigNode *cnode) {
                 c_list_link_tail(&policy->default_entries.send_list, &record->link);
         }
 
-        record = NULL;
+        if (c_list_is_linked(&record->link))
+                record = NULL;
         return 0;
 }
 
@@ -589,7 +591,8 @@ static int policy_import_recv(Policy *policy, ConfigNode *cnode) {
                 c_list_link_tail(&policy->default_entries.recv_list, &record->link);
         }
 
-        record = NULL;
+        if (c_list_is_linked(&record->link))
+                record = NULL;
         return 0;
 }