From b0e50c4e895aa2e8b8469eb359a43778df3db27e Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Wed, 1 Nov 2017 16:32:15 +0300 Subject: [PATCH] tcp_nv: fix division by zero in tcpnv_acked() [ 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 Acked-by: Lawrence Brakmo Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_nv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_nv.c b/net/ipv4/tcp_nv.c index 5de82a8d4d87..e45e2c41c7bd 100644 --- a/net/ipv4/tcp_nv.c +++ b/net/ipv4/tcp_nv.c @@ -263,7 +263,7 @@ static void tcpnv_acked(struct sock *sk, const struct ack_sample *sample) /* 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 -- 2.11.0