1 files changed, 5 insertions, 5 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 40661fc1e233..40639c288dc2 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1106,7 +1106,7 @@ static bool tcp_check_dsack(struct sock *sk, const struct sk_buff *ack_skb,
         }
 
         /* D-SACK for already forgotten data... Do dumb counting. */
-        if (dup_sack && tp->undo_marker && tp->undo_retrans &&
+        if (dup_sack && tp->undo_marker && tp->undo_retrans > 0 &&
             !after(end_seq_0, prior_snd_una) &&
             after(end_seq_0, tp->undo_marker))
                 tp->undo_retrans--;
@@ -1162,7 +1162,7 @@ static int tcp_match_skb_to_sack(struct sock *sk, struct sk_buff *skb,
                         unsigned int new_len = (pkt_len / mss) * mss;
                         if (!in_sack && new_len < pkt_len) {
                                 new_len += mss;
-                                if (new_len > skb->len)
+                                if (new_len >= skb->len)
                                         return 0;
                         }
                         pkt_len = new_len;
@@ -1187,7 +1187,7 @@ static u8 tcp_sacktag_one(struct sock *sk,
 
         /* Account D-SACK for retransmitted packet. */
         if (dup_sack && (sacked & TCPCB_RETRANS)) {
-                if (tp->undo_marker && tp->undo_retrans &&
+                if (tp->undo_marker && tp->undo_retrans > 0 &&
                     after(end_seq, tp->undo_marker))
                         tp->undo_retrans--;
                 if (sacked & TCPCB_SACKED_ACKED)
@@ -1893,7 +1893,7 @@ static void tcp_clear_retrans_partial(struct tcp_sock *tp)
         tp->lost_out = 0;
 
         tp->undo_marker = 0;
-        tp->undo_retrans = 0;
+        tp->undo_retrans = -1;
 }
 
 void tcp_clear_retrans(struct tcp_sock *tp)
@@ -2665,7 +2665,7 @@ static void tcp_enter_recovery(struct sock *sk, bool ece_ack)
 
         tp->prior_ssthresh = 0;
         tp->undo_marker = tp->snd_una;
-        tp->undo_retrans = tp->retrans_out;
+        tp->undo_retrans = tp->retrans_out ? : -1;
 
         if (inet_csk(sk)->icsk_ca_state < TCP_CA_CWR) {
                 if (!ece_ack)