Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 6b74523..3d71c7d 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *	IPv6 input
  *	Linux INET6 implementation
@@ -7,11 +8,6 @@
  *	Ian P. Morris		<I.P.Morris@soton.ac.uk>
  *
  *	Based in linux/net/ipv4/ip_input.c
- *
- *	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.
  */
 /* Changes
  *
@@ -29,6 +25,7 @@
 #include <linux/icmpv6.h>
 #include <linux/mroute6.h>
 #include <linux/slab.h>
+#include <linux/indirect_call_wrapper.h>
 
 #include <linux/netfilter.h>
 #include <linux/netfilter_ipv6.h>
@@ -47,6 +44,8 @@
 #include <net/inet_ecn.h>
 #include <net/dst_metadata.h>
 
+INDIRECT_CALLABLE_DECLARE(void udp_v6_early_demux(struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(void tcp_v6_early_demux(struct sk_buff *));
 static void ip6_rcv_finish_core(struct net *net, struct sock *sk,
 				struct sk_buff *skb)
 {
@@ -57,7 +56,8 @@
 
 		ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
 		if (ipprot && (edemux = READ_ONCE(ipprot->early_demux)))
-			edemux(skb);
+			INDIRECT_CALL_2(edemux, tcp_v6_early_demux,
+					udp_v6_early_demux, skb);
 	}
 	if (!skb_valid_dst(skb))
 		ip6_route_input(skb);
@@ -80,8 +80,10 @@
 {
 	struct sk_buff *skb, *next;
 
-	list_for_each_entry_safe(skb, next, head, list)
+	list_for_each_entry_safe(skb, next, head, list) {
+		skb_list_del_init(skb);
 		dst_input(skb);
+	}
 }
 
 static void ip6_list_rcv_finish(struct net *net, struct sock *sk,
@@ -178,7 +180,8 @@
 	 */
 	if ((ipv6_addr_loopback(&hdr->saddr) ||
 	     ipv6_addr_loopback(&hdr->daddr)) &&
-	     !(dev->flags & IFF_LOOPBACK))
+	    !(dev->flags & IFF_LOOPBACK) &&
+	    !netif_is_l3_master(dev))
 		goto err;
 
 	/* RFC4291 Errata ID: 3480
@@ -220,6 +223,16 @@
 	if (ipv6_addr_is_multicast(&hdr->saddr))
 		goto err;
 
+	/* While RFC4291 is not explicit about v4mapped addresses
+	 * in IPv6 headers, it seems clear linux dual-stack
+	 * model can not deal properly with these.
+	 * Security models could be fooled by ::ffff:127.0.0.1 for example.
+	 *
+	 * https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02
+	 */
+	if (ipv6_addr_v4mapped(&hdr->saddr))
+		goto err;
+
 	skb->transport_header = skb->network_header + sizeof(*hdr);
 	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
 
@@ -315,31 +328,32 @@
 	ip6_sublist_rcv(&sublist, curr_dev, curr_net);
 }
 
+INDIRECT_CALLABLE_DECLARE(int udpv6_rcv(struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *));
+
 /*
  *	Deliver the packet to the host
  */
-
-
-static int ip6_input_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
+void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr,
+			      bool have_final)
 {
 	const struct inet6_protocol *ipprot;
 	struct inet6_dev *idev;
 	unsigned int nhoff;
-	int nexthdr;
 	bool raw;
-	bool have_final = false;
 
 	/*
 	 *	Parse extension headers
 	 */
 
-	rcu_read_lock();
 resubmit:
 	idev = ip6_dst_idev(skb_dst(skb));
-	if (!pskb_pull(skb, skb_transport_offset(skb)))
-		goto discard;
 	nhoff = IP6CB(skb)->nhoff;
-	nexthdr = skb_network_header(skb)[nhoff];
+	if (!have_final) {
+		if (!pskb_pull(skb, skb_transport_offset(skb)))
+			goto discard;
+		nexthdr = skb_network_header(skb)[nhoff];
+	}
 
 resubmit_final:
 	raw = raw6_local_deliver(skb, nexthdr);
@@ -358,6 +372,8 @@
 			}
 		} else if (ipprot->flags & INET6_PROTO_FINAL) {
 			const struct ipv6hdr *hdr;
+			int sdif = inet6_sdif(skb);
+			struct net_device *dev;
 
 			/* Only do this once for first final protocol */
 			have_final = true;
@@ -365,14 +381,24 @@
 			/* Free reference early: we don't need it any more,
 			   and it may hold ip_conntrack module loaded
 			   indefinitely. */
-			nf_reset(skb);
+			nf_reset_ct(skb);
 
 			skb_postpull_rcsum(skb, skb_network_header(skb),
 					   skb_network_header_len(skb));
 			hdr = ipv6_hdr(skb);
+
+			/* skb->dev passed may be master dev for vrfs. */
+			if (sdif) {
+				dev = dev_get_by_index_rcu(net, sdif);
+				if (!dev)
+					goto discard;
+			} else {
+				dev = skb->dev;
+			}
+
 			if (ipv6_addr_is_multicast(&hdr->daddr) &&
-			    !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
-			    &hdr->saddr) &&
+			    !ipv6_chk_mcast_addr(dev, &hdr->daddr,
+						 &hdr->saddr) &&
 			    !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
 				goto discard;
 		}
@@ -380,7 +406,8 @@
 		    !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 			goto discard;
 
-		ret = ipprot->handler(skb);
+		ret = INDIRECT_CALL_2(ipprot->handler, tcp_v6_rcv, udpv6_rcv,
+				      skb);
 		if (ret > 0) {
 			if (ipprot->flags & INET6_PROTO_FINAL) {
 				/* Not an extension header, most likely UDP
@@ -410,13 +437,19 @@
 			consume_skb(skb);
 		}
 	}
-	rcu_read_unlock();
-	return 0;
+	return;
 
 discard:
 	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
-	rcu_read_unlock();
 	kfree_skb(skb);
+}
+
+static int ip6_input_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	rcu_read_lock();
+	ip6_protocol_deliver_rcu(net, skb, 0, false);
+	rcu_read_unlock();
+
 	return 0;
 }
 
@@ -431,15 +464,32 @@
 
 int ip6_mc_input(struct sk_buff *skb)
 {
+	int sdif = inet6_sdif(skb);
 	const struct ipv6hdr *hdr;
+	struct net_device *dev;
 	bool deliver;
 
 	__IP6_UPD_PO_STATS(dev_net(skb_dst(skb)->dev),
 			 __in6_dev_get_safely(skb->dev), IPSTATS_MIB_INMCAST,
 			 skb->len);
 
+	/* skb->dev passed may be master dev for vrfs. */
+	if (sdif) {
+		rcu_read_lock();
+		dev = dev_get_by_index_rcu(dev_net(skb->dev), sdif);
+		if (!dev) {
+			rcu_read_unlock();
+			kfree_skb(skb);
+			return -ENODEV;
+		}
+	} else {
+		dev = skb->dev;
+	}
+
 	hdr = ipv6_hdr(skb);
-	deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
+	deliver = ipv6_chk_mcast_addr(dev, &hdr->daddr, NULL);
+	if (sdif)
+		rcu_read_unlock();
 
 #ifdef CONFIG_IPV6_MROUTE
 	/*