Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/security/keys/persistent.c b/security/keys/persistent.c
index d0cb5b3..97af230 100644
--- a/security/keys/persistent.c
+++ b/security/keys/persistent.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* General persistent per-UID keyrings register
  *
  * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
  */
 
 #include <linux/user_namespace.h>
@@ -84,15 +80,17 @@
 	long ret;
 
 	/* Look in the register if it exists */
+	memset(&index_key, 0, sizeof(index_key));
 	index_key.type = &key_type_keyring;
 	index_key.description = buf;
 	index_key.desc_len = sprintf(buf, "_persistent.%u", from_kuid(ns, uid));
+	key_set_index_key(&index_key);
 
 	if (ns->persistent_keyring_register) {
 		reg_ref = make_key_ref(ns->persistent_keyring_register, true);
-		down_read(&ns->persistent_keyring_register_sem);
+		down_read(&ns->keyring_sem);
 		persistent_ref = find_key_to_update(reg_ref, &index_key);
-		up_read(&ns->persistent_keyring_register_sem);
+		up_read(&ns->keyring_sem);
 
 		if (persistent_ref)
 			goto found;
@@ -101,9 +99,9 @@
 	/* It wasn't in the register, so we'll need to create it.  We might
 	 * also need to create the register.
 	 */
-	down_write(&ns->persistent_keyring_register_sem);
+	down_write(&ns->keyring_sem);
 	persistent_ref = key_create_persistent(ns, uid, &index_key);
-	up_write(&ns->persistent_keyring_register_sem);
+	up_write(&ns->keyring_sem);
 	if (!IS_ERR(persistent_ref))
 		goto found;