activation test: Fix time-of-check/time-of-use bug waiting to happen

Creating a directory is atomic, stat'ing it to see whether to remove
it is very much not.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=99828
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Philip Withnall <withnall@endlessm.com>

diff --git a/bus/activation.c b/bus/activation.c
index 1211329..1a98af6 100644 (file)
--- a/bus/activation.c
+++ b/bus/activation.c
@@ -2436,21 +2436,8 @@ out:
 static dbus_bool_t
 init_service_reload_test (DBusString *dir)
 {
-  DBusStat stat_buf;
-
-  if (!_dbus_stat (dir, &stat_buf, NULL))
-    {
-      if (!_dbus_create_directory (dir, NULL))
-        return FALSE;
-    }
-  else
-    {
-      if (!test_remove_directory (dir))
-        return FALSE;
-
-      if (!_dbus_create_directory (dir, NULL))
-        return FALSE;
-    }
+  if (!_dbus_create_directory (dir, NULL))
+    return FALSE;
 
   /* Create one initial file */
   if (!test_create_service_file (dir, SERVICE_FILE_1, SERVICE_NAME_1, "exec-1"))
@@ -2638,6 +2625,9 @@ bus_activation_service_reload_test (const DBusString *test_data_dir)
       /* Do nothing? */
     }
 
+  if (!cleanup_service_reload_test (&directory))
+    goto out;
+
   /* Do OOM tests */
   if (!init_service_reload_test (&directory))
     _dbus_assert_not_reached ("could not initiate service reload test");