6 files changed, 31 insertions, 6 deletions

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 7bd8983dbfc..96da9c77dec 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -287,7 +287,7 @@ begintw:
 			if (unlikely(!INET_TW_MATCH(sk, net, acookie,
 						    saddr, daddr, ports,
 						    dif))) {
-				sock_put(sk);
+				inet_twsk_put(inet_twsk(sk));
 				goto begintw;
 			}
 			goto out;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e6bb8256e59..c6f01f2cdb3 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -637,6 +637,8 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb
 	unsigned int size = 0;
 	unsigned int eff_sacks;
 
+	opts->options = 0;
+
 #ifdef CONFIG_TCP_MD5SIG
 	*md5 = tp->af_specific->md5_lookup(sk, sk);
 	if (unlikely(*md5)) {
diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index 32b4a1675d8..066640e0ba8 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -116,7 +116,7 @@ begintw:
 			}
 			if (unlikely(!INET6_TW_MATCH(sk, net, saddr, daddr,
 						     ports, dif))) {
-				sock_put(sk);
+				inet_twsk_put(inet_twsk(sk));
 				goto begintw;
 			}
 			goto out;
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index feae495a0a3..aedaa2cd423 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -496,6 +496,7 @@ out:
 static inline int l2tp_verify_udp_checksum(struct sock *sk,
 					   struct sk_buff *skb)
 {
+	struct l2tp_tunnel *tunnel = (struct l2tp_tunnel *)sk->sk_user_data;
 	struct udphdr *uh = udp_hdr(skb);
 	u16 ulen = ntohs(uh->len);
 	__wsum psum;
@@ -504,7 +505,7 @@ static inline int l2tp_verify_udp_checksum(struct sock *sk,
 		return 0;
 
 #if IS_ENABLED(CONFIG_IPV6)
-	if (sk->sk_family == PF_INET6) {
+	if (sk->sk_family == PF_INET6 && !tunnel->v4mapped) {
 		if (!uh->check) {
 			LIMIT_NETDEBUG(KERN_INFO "L2TP: IPv6: checksum is 0\n");
 			return 1;
@@ -1128,7 +1129,7 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb,
 	/* Queue the packet to IP for output */
 	skb->local_df = 1;
 #if IS_ENABLED(CONFIG_IPV6)
-	if (skb->sk->sk_family == PF_INET6)
+	if (skb->sk->sk_family == PF_INET6 && !tunnel->v4mapped)
 		error = inet6_csk_xmit(skb, NULL);
 	else
 #endif
@@ -1255,7 +1256,7 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 
 		/* Calculate UDP checksum if configured to do so */
 #if IS_ENABLED(CONFIG_IPV6)
-		if (sk->sk_family == PF_INET6)
+		if (sk->sk_family == PF_INET6 && !tunnel->v4mapped)
 			l2tp_xmit_ipv6_csum(sk, skb, udp_len);
 		else
 #endif
@@ -1704,6 +1705,24 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 	if (cfg != NULL)
 		tunnel->debug = cfg->debug;
 
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sk->sk_family == PF_INET6) {
+		struct ipv6_pinfo *np = inet6_sk(sk);
+
+		if (ipv6_addr_v4mapped(&np->saddr) &&
+		    ipv6_addr_v4mapped(&np->daddr)) {
+			struct inet_sock *inet = inet_sk(sk);
+
+			tunnel->v4mapped = true;
+			inet->inet_saddr = np->saddr.s6_addr32[3];
+			inet->inet_rcv_saddr = np->rcv_saddr.s6_addr32[3];
+			inet->inet_daddr = np->daddr.s6_addr32[3];
+		} else {
+			tunnel->v4mapped = false;
+		}
+	}
+#endif
+
 	/* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
 	tunnel->encap = encap;
 	if (encap == L2TP_ENCAPTYPE_UDP) {
@@ -1712,7 +1731,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 		udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv;
 		udp_sk(sk)->encap_destroy = l2tp_udp_encap_destroy;
 #if IS_ENABLED(CONFIG_IPV6)
-		if (sk->sk_family == PF_INET6)
+		if (sk->sk_family == PF_INET6 && !tunnel->v4mapped)
 			udpv6_encap_enable();
 		else
 #endif
diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index 66a559b104b..6f251cbc2ed 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -194,6 +194,9 @@ struct l2tp_tunnel {
 	struct sock		*sock;		/* Parent socket */
 	int			fd;		/* Parent fd, if tunnel socket
 						 * was created by userspace */
+#if IS_ENABLED(CONFIG_IPV6)
+	bool			v4mapped;
+#endif
 
 	struct work_struct	del_work;
 
diff --git a/net/unix/diag.c b/net/unix/diag.c
index d591091603b..86fa0f3b2ca 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -124,6 +124,7 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_r
 	rep->udiag_family = AF_UNIX;
 	rep->udiag_type = sk->sk_type;
 	rep->udiag_state = sk->sk_state;
+	rep->pad = 0;
 	rep->udiag_ino = sk_ino;
 	sock_diag_save_cookie(sk, rep->udiag_cookie);