1 files changed, 8 insertions, 2 deletions

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index f813077234b7..0474f4c5707a 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -329,8 +329,14 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
                         hctx->ccid3hctx_x    = rfc3390_initial_rate(sk);
                         hctx->ccid3hctx_t_ld = now;
                 } else {
-                        /* Sender does not have RTT sample: X_pps = 1 pkt/sec */
-                        hctx->ccid3hctx_x = hctx->ccid3hctx_s;
+                        /*
+                         * Sender does not have RTT sample:
+                         * - set fallback RTT (RFC 4340, 3.4) since a RTT value
+                         *   is needed in several parts (e.g.  window counter);
+                         * - set sending rate X_pps = 1pps as per RFC 3448, 4.2.
+                         */
+                        hctx->ccid3hctx_rtt = DCCP_FALLBACK_RTT;
+                        hctx->ccid3hctx_x   = hctx->ccid3hctx_s;
                         hctx->ccid3hctx_x <<= 6;
                 }
                 ccid3_update_send_interval(hctx);