Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c
index 35f6f86..0d7c887 100644
--- a/net/l2tp/l2tp_ip.c
+++ b/net/l2tp/l2tp_ip.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * L2TPv3 IP encapsulation support
  *
  * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
- *
- *	This program is free software; you can redistribute it and/or
- *	modify it under the terms of the GNU General Public License
- *	as published by the Free Software Foundation; either version
- *	2 of the License, or (at your option) any later version.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -165,6 +161,9 @@
 		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
 	}
 
+	if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr))
+		goto discard_sess;
+
 	l2tp_recv_common(session, skb, ptr, optr, 0, skb->len);
 	l2tp_session_dec_refcount(session);
 
@@ -194,7 +193,7 @@
 	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
 		goto discard_put;
 
-	nf_reset(skb);
+	nf_reset_ct(skb);
 
 	return sk_receive_skb(sk, skb, 1);
 
@@ -615,6 +614,7 @@
 	.getname	   = l2tp_ip_getname,
 	.poll		   = datagram_poll,
 	.ioctl		   = inet_ioctl,
+	.gettstamp	   = sock_gettstamp,
 	.listen		   = sock_no_listen,
 	.shutdown	   = inet_shutdown,
 	.setsockopt	   = sock_common_setsockopt,