1 files changed, 7 insertions, 1 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 32b048e524d6..7158d4f8dae4 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -814,8 +814,14 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
         u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 :
                                              tcp_sk(sk)->snd_nxt;
 
+        /* RFC 7323 2.3
+         * The window field (SEG.WND) of every outgoing segment, with the
+         * exception of <SYN> segments, MUST be right-shifted by
+         * Rcv.Wind.Shift bits:
+         */
         tcp_v4_send_ack(sock_net(sk), skb, seq,
-                        tcp_rsk(req)->rcv_nxt, req->rsk_rcv_wnd,
+                        tcp_rsk(req)->rcv_nxt,
+                        req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
                         tcp_time_stamp,
                         req->ts_recent,
                         0,