From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753176AbdKVKPn (ORCPT ); Wed, 22 Nov 2017 05:15:43 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:33502 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753149AbdKVKPg (ORCPT ); Wed, 22 Nov 2017 05:15:36 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Konstantin Khlebnikov , Lawrence Brakmo , "David S. Miller" Subject: [PATCH 4.13 01/35] tcp_nv: fix division by zero in tcpnv_acked() Date: Wed, 22 Nov 2017 11:11:55 +0100 Message-Id: <20171122101137.854660134@linuxfoundation.org> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20171122101137.661212603@linuxfoundation.org> References: <20171122101137.661212603@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Konstantin Khlebnikov [ 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(-) --- 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