1 files changed, 33 insertions, 8 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 5f47c0b6e3de..0ce52d46e4f8 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -348,11 +348,20 @@ failure:
 static void tcp_v6_mtu_reduced(struct sock *sk)
 {
 	struct dst_entry *dst;
+	u32 mtu;
 
 	if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 		return;
 
-	dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
+	mtu = READ_ONCE(tcp_sk(sk)->mtu_info);
+
+	/* Drop requests trying to increase our current mss.
+	 * Check done in __ip6_rt_update_pmtu() is too late.
+	 */
+	if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache)
+		return;
+
+	dst = inet6_csk_update_pmtu(sk, mtu);
 	if (!dst)
 		return;
 
@@ -433,6 +442,8 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	}
 
 	if (type == ICMPV6_PKT_TOOBIG) {
+		u32 mtu = ntohl(info);
+
 		/* We are not interested in TCP_LISTEN and open_requests
 		 * (SYN-ACKs send out by Linux are always <576bytes so
 		 * they should go through unfragmented).
@@ -443,7 +454,11 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 		if (!ip6_sk_accept_pmtu(sk))
 			goto out;
 
-		tp->mtu_info = ntohl(info);
+		if (mtu < IPV6_MIN_MTU)
+			goto out;
+
+		WRITE_ONCE(tp->mtu_info, mtu);
+
 		if (!sock_owned_by_user(sk))
 			tcp_v6_mtu_reduced(sk);
 		else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
@@ -467,7 +482,7 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 		if (!sock_owned_by_user(sk)) {
 			sk->sk_err = err;
-			sk->sk_error_report(sk);		/* Wake people up to see the error (see connect in sock.c) */
+			sk_error_report(sk);		/* Wake people up to see the error (see connect in sock.c) */
 
 			tcp_done(sk);
 		} else
@@ -486,7 +501,7 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 	if (!sock_owned_by_user(sk) && np->recverr) {
 		sk->sk_err = err;
-		sk->sk_error_report(sk);
+		sk_error_report(sk);
 	} else
 		sk->sk_err_soft = err;
 
@@ -540,7 +555,7 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
 		opt = ireq->ipv6_opt;
 		if (!opt)
 			opt = rcu_dereference(np->opt);
-		err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt,
+		err = ip6_xmit(sk, skb, fl6, skb->mark ? : sk->sk_mark, opt,
 			       tclass, sk->sk_priority);
 		rcu_read_unlock();
 		err = net_xmit_eval(err);
@@ -1538,6 +1553,7 @@ discard:
 	kfree_skb(skb);
 	return 0;
 csum_err:
+	trace_tcp_bad_csum(skb);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
 	goto discard;
@@ -1663,10 +1679,18 @@ process:
 			goto csum_error;
 		}
 		if (unlikely(sk->sk_state != TCP_LISTEN)) {
-			inet_csk_reqsk_queue_drop_and_put(sk, req);
-			goto lookup;
+			nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb);
+			if (!nsk) {
+				inet_csk_reqsk_queue_drop_and_put(sk, req);
+				goto lookup;
+			}
+			sk = nsk;
+			/* reuseport_migrate_sock() has already held one sk_refcnt
+			 * before returning.
+			 */
+		} else {
+			sock_hold(sk);
 		}
-		sock_hold(sk);
 		refcounted = true;
 		nsk = NULL;
 		if (!tcp_filter(sk, skb)) {
@@ -1754,6 +1778,7 @@ no_tcp_socket:
 
 	if (tcp_checksum_complete(skb)) {
 csum_error:
+		trace_tcp_bad_csum(skb);
 		__TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
 bad_packet:
 		__TCP_INC_STATS(net, TCP_MIB_INERRS);