diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 0f60a1dbf927..92bc60716f33 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6490,6 +6490,7 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
  *	  or pure receivers (this means either the sequence number or the ack
  *	  value must stay constant)
  *	- Unexpected TCP option.
+ *	- ACK sequence number is outside [SND.UNA, SND.NXT].
  *
  *	When these conditions are not satisfied it drops into a standard
  *	receive procedure patterned after RFC793 to handle all cases.
@@ -6539,7 +6540,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
 
 	if ((tcp_flag_word(th) & TCP_HP_BITS) == tp->pred_flags &&
 	    TCP_SKB_CB(skb)->seq == tp->rcv_nxt &&
-	    !after(TCP_SKB_CB(skb)->ack_seq, tp->snd_nxt)) {
+	    between(TCP_SKB_CB(skb)->ack_seq, tp->snd_una, tp->snd_nxt)) {
 		int tcp_header_len = tp->tcp_header_len;
 		s32 delta = 0;
 		int flag = 0;