Merge branch 'net-fix-reuseaddr-regression'

Josef Bacik says:

====================
net: fix reuseaddr regression

I introduced a regression when reworking the fastreuse port stuff that allows
bind conflicts to occur once a reuseaddr successfully opens on an existing tb.
The root cause is I reversed an if statement which caused us to set the tb as if
there were no owners on the socket if there were, which obviously is not
correct.

Dave could you please queue these changes up for -stable, I've run them through
the net tests and added another test to check for this problem specifically.
====================

Signed-off-by: David S. Miller <[email protected]>

net/ipv4/inet_connection_sock.c

@@ -266,7 +266,7 @@ static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
 #if IS_ENABLED(CONFIG_IPV6)
 	if (tb->fast_sk_family == AF_INET6)
 		return ipv6_rcv_saddr_equal(&tb->fast_v6_rcv_saddr,
-					    &sk->sk_v6_rcv_saddr,
+					    inet6_rcv_saddr(sk),
 					    tb->fast_rcv_saddr,
 					    sk->sk_rcv_saddr,
 					    tb->fast_ipv6_only,
@@ -321,13 +321,14 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
 			goto fail_unlock;
 	}
 success:
-	if (!hlist_empty(&tb->owners)) {
+	if (hlist_empty(&tb->owners)) {
 		tb->fastreuse = reuse;
 		if (sk->sk_reuseport) {
 			tb->fastreuseport = FASTREUSEPORT_ANY;
 			tb->fastuid = uid;
 			tb->fast_rcv_saddr = sk->sk_rcv_saddr;
 			tb->fast_ipv6_only = ipv6_only_sock(sk);
+			tb->fast_sk_family = sk->sk_family;
 #if IS_ENABLED(CONFIG_IPV6)
 			tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 #endif
@@ -354,6 +355,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
 				tb->fastuid = uid;
 				tb->fast_rcv_saddr = sk->sk_rcv_saddr;
 				tb->fast_ipv6_only = ipv6_only_sock(sk);
+				tb->fast_sk_family = sk->sk_family;
 #if IS_ENABLED(CONFIG_IPV6)
 				tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 #endif