diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 684f095..923e0e5 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -109,6 +109,7 @@
 #define FLAG_SYN_ACKED		0x10 /* This ACK acknowledged SYN.		*/
 #define FLAG_DATA_SACKED	0x20 /* New SACK.				*/
 #define FLAG_ECE		0x40 /* ECE in this ACK				*/
+#define FLAG_LOST_RETRANS	0x80 /* This ACK marks some retransmission lost */
 #define FLAG_SLOWPATH		0x100 /* Do not skip RFC checks for window update.*/
 #define FLAG_ORIG_SACK_ACKED	0x200 /* Never retransmitted data are (s)acked	*/
 #define FLAG_SND_UNA_ADVANCED	0x400 /* Snd_una was changed (!= FLAG_DATA_ACKED) */
@@ -1037,7 +1038,7 @@
  * highest SACK block). Also calculate the lowest snd_nxt among the remaining
  * retransmitted skbs to avoid some costly processing per ACKs.
  */
-static void tcp_mark_lost_retrans(struct sock *sk)
+static void tcp_mark_lost_retrans(struct sock *sk, int *flag)
 {
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -1078,7 +1079,7 @@
 		if (after(received_upto, ack_seq)) {
 			TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
 			tp->retrans_out -= tcp_skb_pcount(skb);
-
+			*flag |= FLAG_LOST_RETRANS;
 			tcp_skb_mark_lost_uncond_verify(tp, skb);
 			NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSTRETRANSMIT);
 		} else {
@@ -1818,7 +1819,7 @@
 	    ((inet_csk(sk)->icsk_ca_state != TCP_CA_Loss) || tp->undo_marker))
 		tcp_update_reordering(sk, tp->fackets_out - state->reord, 0);
 
-	tcp_mark_lost_retrans(sk);
+	tcp_mark_lost_retrans(sk, &state->flag);
 	tcp_verify_left_out(tp);
 out:
 
@@ -2676,7 +2677,7 @@
 	tp->prior_ssthresh = 0;
 	tcp_init_undo(tp);
 
-	if (inet_csk(sk)->icsk_ca_state < TCP_CA_CWR) {
+	if (!tcp_in_cwnd_reduction(sk)) {
 		if (!ece_ack)
 			tp->prior_ssthresh = tcp_current_ssthresh(sk);
 		tcp_init_cwnd_reduction(sk);
@@ -2852,9 +2853,10 @@
 		break;
 	case TCP_CA_Loss:
 		tcp_process_loss(sk, flag, is_dupack);
-		if (icsk->icsk_ca_state != TCP_CA_Open)
+		if (icsk->icsk_ca_state != TCP_CA_Open &&
+		    !(flag & FLAG_LOST_RETRANS))
 			return;
-		/* Fall through to processing in Open state. */
+		/* Change state if cwnd is undone or retransmits are lost */
 	default:
 		if (tcp_is_reno(tp)) {
 			if (flag & FLAG_SND_UNA_ADVANCED)