1 files changed, 7 insertions, 0 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index d65d17bb2a09..9df5b2a4da6e 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -692,6 +692,9 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
         TCP_SKB_CB(buff)->end_seq = TCP_SKB_CB(skb)->end_seq;
         TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(buff)->seq;
 
+        if (tp->sacked_out && (TCP_SKB_CB(skb)->seq == tp->highest_sack))
+                tp->highest_sack = TCP_SKB_CB(buff)->seq;
+
         /* PSH and FIN should only be set in the second packet. */
         flags = TCP_SKB_CB(skb)->flags;
         TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
@@ -1723,6 +1726,10 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
                 /* Update sequence range on original skb. */
                 TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq;
 
+                if (WARN_ON(tp->sacked_out &&
+                    (TCP_SKB_CB(next_skb)->seq == tp->highest_sack)))
+                        return;
+
                 /* Merge over control information. */
                 flags |= TCP_SKB_CB(next_skb)->flags; /* This moves PSH/FIN etc. over */
                 TCP_SKB_CB(skb)->flags = flags;