diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 12ae9a68cdaa..3f126ece8eb5 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1269,6 +1269,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
 	if (before(TCP_SKB_CB(ack_skb)->ack_seq, prior_snd_una - tp->max_window))
 		return 0;
 
+	if (!tp->packets_out)
+		goto out;
+
 	/* SACK fastpath:
 	 * if the only SACK change is the increase of the end_seq of
 	 * the first block then only apply that SACK block
@@ -1515,6 +1518,8 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
 	    (!tp->frto_highmark || after(tp->snd_una, tp->frto_highmark)))
 		tcp_update_reordering(sk, tp->fackets_out - reord, 0);
 
+out:
+
 #if FASTRETRANS_DEBUG > 0
 	BUG_TRAP((int)tp->sacked_out >= 0);
 	BUG_TRAP((int)tp->lost_out >= 0);