diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 8a1c5698983c..2d25f319f328 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -570,7 +570,6 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb,
 	struct mptcp_ext *mpext;
 	unsigned int ack_size;
 	bool ret = false;
-	u64 ack_seq;
 
 	opts->csum_reqd = READ_ONCE(msk->csum_enabled);
 	mpext = skb ? mptcp_get_ext(skb) : NULL;
@@ -601,14 +600,11 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb,
 		return ret;
 	}
 
-	ack_seq = READ_ONCE(msk->ack_seq);
 	if (READ_ONCE(msk->use_64bit_ack)) {
 		ack_size = TCPOLEN_MPTCP_DSS_ACK64;
-		opts->ext_copy.data_ack = ack_seq;
 		opts->ext_copy.ack64 = 1;
 	} else {
 		ack_size = TCPOLEN_MPTCP_DSS_ACK32;
-		opts->ext_copy.data_ack32 = (uint32_t)ack_seq;
 		opts->ext_copy.ack64 = 0;
 	}
 	opts->ext_copy.use_ack = 1;
@@ -1297,19 +1293,14 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 	return true;
 }
 
-static void mptcp_set_rwin(struct tcp_sock *tp, struct tcphdr *th)
+static u64 mptcp_set_rwin(struct mptcp_sock *msk, struct tcp_sock *tp,
+			  struct tcphdr *th, u64 ack_seq)
 {
 	const struct sock *ssk = (const struct sock *)tp;
-	struct mptcp_subflow_context *subflow;
-	u64 ack_seq, rcv_wnd_old, rcv_wnd_new;
-	struct mptcp_sock *msk;
+	u64 rcv_wnd_old, rcv_wnd_new;
 	u32 new_win;
 	u64 win;
 
-	subflow = mptcp_subflow_ctx(ssk);
-	msk = mptcp_sk(subflow->conn);
-
-	ack_seq = READ_ONCE(msk->ack_seq);
 	rcv_wnd_new = ack_seq + tp->rcv_wnd;
 
 	rcv_wnd_old = atomic64_read(&msk->rcv_wnd_sent);
@@ -1362,7 +1353,7 @@ static void mptcp_set_rwin(struct tcp_sock *tp, struct tcphdr *th)
 
 update_wspace:
 	WRITE_ONCE(msk->old_wspace, tp->rcv_wnd);
-	subflow->rcv_wnd_sent = rcv_wnd_new;
+	return rcv_wnd_new;
 }
 
 static void mptcp_track_rwin(struct tcp_sock *tp)
@@ -1474,13 +1465,25 @@ void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
 		*ptr++ = mptcp_option(MPTCPOPT_DSS, len, 0, flags);
 
 		if (mpext->use_ack) {
+			struct mptcp_sock *msk;
+			u64 ack_seq;
+
+			/* DSS option is set only by mptcp_established_options,
+			 * the caller is __tcp_transmit_skb() and ssk is always
+			 * not NULL.
+			 */
+			subflow = mptcp_subflow_ctx(ssk);
+			msk = mptcp_sk(subflow->conn);
+			ack_seq = READ_ONCE(msk->ack_seq);
 			if (mpext->ack64) {
-				put_unaligned_be64(mpext->data_ack, ptr);
+				put_unaligned_be64(ack_seq, ptr);
 				ptr += 2;
 			} else {
-				put_unaligned_be32(mpext->data_ack32, ptr);
+				put_unaligned_be32(ack_seq, ptr);
 				ptr += 1;
 			}
+			subflow->rcv_wnd_sent = mptcp_set_rwin(msk, tp, th,
+							       ack_seq);
 		}
 
 		if (mpext->use_map) {
@@ -1708,9 +1711,6 @@ void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
 			i += 4;
 		}
 	}
-
-	if (tp)
-		mptcp_set_rwin(tp, th);
 }
 
 __be32 mptcp_get_reset_option(const struct sk_buff *skb)