4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> [ Upstream commit 4eebff27ca4182bbf5f039dd60d79e2d7c0a707e ] Average RTT could become zero. This happened in real life at least twice. This patch treats zero as 1us. Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> Acked-by: Lawrence Brakmo <Brakmo@xxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/tcp_nv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/tcp_nv.c +++ b/net/ipv4/tcp_nv.c @@ -263,7 +263,7 @@ static void tcpnv_acked(struct sock *sk, /* rate in 100's bits per second */ rate64 = ((u64)sample->in_flight) * 8000000; - rate = (u32)div64_u64(rate64, (u64)(avg_rtt * 100)); + rate = (u32)div64_u64(rate64, (u64)(avg_rtt ?: 1) * 100); /* Remember the maximum rate seen during this RTT * Note: It may be more than one RTT. This function should be