1 files changed, 2 insertions, 1 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 305cd0526a78..6ffe41a82c00 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2856,7 +2856,8 @@ static inline bool tcp_ack_update_rtt(struct sock *sk, const int flag,
          * left edge of the send window.
          * See draft-ietf-tcplw-high-performance-00, section 3.3.
          */
-        if (seq_rtt < 0 && tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr)
+        if (seq_rtt < 0 && tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr &&
+            flag & FLAG_ACKED)
                 seq_rtt = tcp_time_stamp - tp->rx_opt.rcv_tsecr;
 
         if (seq_rtt < 0)