Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/key/Makefile b/net/key/Makefile
index 8576080..ed779c2 100644
--- a/net/key/Makefile
+++ b/net/key/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Makefile for the key AF.
 #
diff --git a/net/key/af_key.c b/net/key/af_key.c
index 9d61266..b67ed3a 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1,11 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * net/key/af_key.c	An implementation of PF_KEYv2 sockets.
  *
- *		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.
- *
  * Authors:	Maxim Giryaev	<gem@asplinux.ru>
  *		David S. Miller	<davem@redhat.com>
  *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
@@ -196,30 +192,22 @@
 	return 0;
 }
 
-static int pfkey_broadcast_one(struct sk_buff *skb, struct sk_buff **skb2,
-			       gfp_t allocation, struct sock *sk)
+static int pfkey_broadcast_one(struct sk_buff *skb, gfp_t allocation,
+			       struct sock *sk)
 {
 	int err = -ENOBUFS;
 
-	sock_hold(sk);
-	if (*skb2 == NULL) {
-		if (refcount_read(&skb->users) != 1) {
-			*skb2 = skb_clone(skb, allocation);
-		} else {
-			*skb2 = skb;
-			refcount_inc(&skb->users);
-		}
+	if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
+		return err;
+
+	skb = skb_clone(skb, allocation);
+
+	if (skb) {
+		skb_set_owner_r(skb, sk);
+		skb_queue_tail(&sk->sk_receive_queue, skb);
+		sk->sk_data_ready(sk);
+		err = 0;
 	}
-	if (*skb2 != NULL) {
-		if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {
-			skb_set_owner_r(*skb2, sk);
-			skb_queue_tail(&sk->sk_receive_queue, *skb2);
-			sk->sk_data_ready(sk);
-			*skb2 = NULL;
-			err = 0;
-		}
-	}
-	sock_put(sk);
 	return err;
 }
 
@@ -234,7 +222,6 @@
 {
 	struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);
 	struct sock *sk;
-	struct sk_buff *skb2 = NULL;
 	int err = -ESRCH;
 
 	/* XXX Do we need something like netlink_overrun?  I think
@@ -253,7 +240,7 @@
 		 * socket.
 		 */
 		if (pfk->promisc)
-			pfkey_broadcast_one(skb, &skb2, GFP_ATOMIC, sk);
+			pfkey_broadcast_one(skb, GFP_ATOMIC, sk);
 
 		/* the exact target will be processed later */
 		if (sk == one_sk)
@@ -268,7 +255,7 @@
 				continue;
 		}
 
-		err2 = pfkey_broadcast_one(skb, &skb2, GFP_ATOMIC, sk);
+		err2 = pfkey_broadcast_one(skb, GFP_ATOMIC, sk);
 
 		/* Error is cleared after successful sending to at least one
 		 * registered KM */
@@ -278,9 +265,8 @@
 	rcu_read_unlock();
 
 	if (one_sk != NULL)
-		err = pfkey_broadcast_one(skb, &skb2, allocation, one_sk);
+		err = pfkey_broadcast_one(skb, allocation, one_sk);
 
-	kfree_skb(skb2);
 	kfree_skb(skb);
 	return err;
 }
@@ -942,8 +928,7 @@
 		pfkey_sockaddr_fill(&x->props.saddr, 0,
 				    (struct sockaddr *) (addr + 1),
 				    x->props.family);
-	if (!addr->sadb_address_prefixlen)
-		BUG();
+	BUG_ON(!addr->sadb_address_prefixlen);
 
 	/* dst address */
 	addr = skb_put(skb, sizeof(struct sadb_address) + sockaddr_size);
@@ -958,8 +943,7 @@
 		pfkey_sockaddr_fill(&x->id.daddr, 0,
 				    (struct sockaddr *) (addr + 1),
 				    x->props.family);
-	if (!addr->sadb_address_prefixlen)
-		BUG();
+	BUG_ON(!addr->sadb_address_prefixlen);
 
 	if (!xfrm_addr_equal(&x->sel.saddr, &x->props.saddr,
 			     x->props.family)) {
@@ -1783,7 +1767,7 @@
 	if (proto == 0)
 		return -EINVAL;
 
-	err = xfrm_state_flush(net, proto, true);
+	err = xfrm_state_flush(net, proto, true, false);
 	err2 = unicast_flush_resp(sk, hdr);
 	if (err || err2) {
 		if (err == -ESRCH) /* empty table - go quietly */
@@ -1961,8 +1945,10 @@
 
 	if (rq->sadb_x_ipsecrequest_mode == 0)
 		return -EINVAL;
+	if (!xfrm_id_proto_valid(rq->sadb_x_ipsecrequest_proto))
+		return -EINVAL;
 
-	t->id.proto = rq->sadb_x_ipsecrequest_proto; /* XXX check proto */
+	t->id.proto = rq->sadb_x_ipsecrequest_proto;
 	if ((mode = pfkey_mode_to_xfrm(rq->sadb_x_ipsecrequest_mode)) < 0)
 		return -EINVAL;
 	t->mode = mode;
@@ -2020,7 +2006,7 @@
 
 static inline int pfkey_xfrm_policy2sec_ctx_size(const struct xfrm_policy *xp)
 {
-  struct xfrm_sec_ctx *xfrm_ctx = xp->security;
+	struct xfrm_sec_ctx *xfrm_ctx = xp->security;
 
 	if (xfrm_ctx) {
 		int len = sizeof(struct sadb_x_sec_ctx);
@@ -2450,8 +2436,10 @@
 		goto out;
 	}
 	err = pfkey_xfrm_policy2msg(out_skb, xp, dir);
-	if (err < 0)
+	if (err < 0) {
+		kfree_skb(out_skb);
 		goto out;
+	}
 
 	out_hdr = (struct sadb_msg *) out_skb->data;
 	out_hdr->sadb_msg_version = hdr->sadb_msg_version;
@@ -2702,8 +2690,10 @@
 		return PTR_ERR(out_skb);
 
 	err = pfkey_xfrm_policy2msg(out_skb, xp, dir);
-	if (err < 0)
+	if (err < 0) {
+		kfree_skb(out_skb);
 		return err;
+	}
 
 	out_hdr = (struct sadb_msg *) out_skb->data;
 	out_hdr->sadb_msg_version = pfk->dump.msg_version;