1 files changed, 8 insertions, 2 deletions

diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index c6ded6b2a79f..448c2615fece 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -154,14 +154,20 @@ static void bictcp_init(struct sock *sk)
 static void bictcp_cwnd_event(struct sock *sk, enum tcp_ca_event event)
 {
         if (event == CA_EVENT_TX_START) {
-                s32 delta = tcp_time_stamp - tcp_sk(sk)->lsndtime;
                 struct bictcp *ca = inet_csk_ca(sk);
+                u32 now = tcp_time_stamp;
+                s32 delta;
+
+                delta = now - tcp_sk(sk)->lsndtime;
 
                 /* We were application limited (idle) for a while.
                  * Shift epoch_start to keep cwnd growth to cubic curve.
                  */
-                if (ca->epoch_start && delta > 0)
+                if (ca->epoch_start && delta > 0) {
                         ca->epoch_start += delta;
+                        if (after(ca->epoch_start, now))
+                                ca->epoch_start = now;
+                }
                 return;
         }
 }