1 files changed, 5 insertions, 0 deletions

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);