Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 6a74080..eecac1b 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * xfrm6_output.c - Common IPsec encapsulation code for IPv6.
  * Copyright (C) 2002 USAGI/WIDE Project
  * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
- *
- * 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.
  */
 
 #include <linux/if_ether.h>
@@ -111,21 +107,6 @@
 	return xfrm6_extract_header(skb);
 }
 
-int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
-{
-	int err;
-
-	err = xfrm_inner_extract_output(x, skb);
-	if (err)
-		return err;
-
-	skb->ignore_df = 1;
-	skb->protocol = htons(ETH_P_IPV6);
-
-	return x->outer_mode->output2(x, skb);
-}
-EXPORT_SYMBOL(xfrm6_prepare_output);
-
 int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb)
 {
 	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
@@ -137,11 +118,28 @@
 	return xfrm_output(sk, skb);
 }
 
+static int __xfrm6_output_state_finish(struct xfrm_state *x, struct sock *sk,
+				       struct sk_buff *skb)
+{
+	const struct xfrm_state_afinfo *afinfo;
+	int ret = -EAFNOSUPPORT;
+
+	rcu_read_lock();
+	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
+	if (likely(afinfo))
+		ret = afinfo->output_finish(sk, skb);
+	else
+		kfree_skb(skb);
+	rcu_read_unlock();
+
+	return ret;
+}
+
 static int __xfrm6_output_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct xfrm_state *x = skb_dst(skb)->xfrm;
 
-	return x->outer_mode->afinfo->output_finish(sk, skb);
+	return __xfrm6_output_state_finish(x, sk, skb);
 }
 
 static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
@@ -183,7 +181,7 @@
 				    __xfrm6_output_finish);
 
 skip_frag:
-	return x->outer_mode->afinfo->output_finish(sk, skb);
+	return __xfrm6_output_state_finish(x, sk, skb);
 }
 
 int xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)