From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47822 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752361AbdKUMlC (ORCPT ); Tue, 21 Nov 2017 07:41:02 -0500 Subject: Patch "tcp_nv: fix division by zero in tcpnv_acked()" has been added to the 4.9-stable tree To: khlebnikov@yandex-team.ru, Brakmo@fb.com, davem@davemloft.net, gregkh@linuxfoundation.org Cc: , From: Date: Tue, 21 Nov 2017 13:40:58 +0100 Message-ID: <151126805857198@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled tcp_nv: fix division by zero in tcpnv_acked() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tcp_nv-fix-division-by-zero-in-tcpnv_acked.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Tue Nov 21 13:08:13 CET 2017 From: Konstantin Khlebnikov Date: Wed, 1 Nov 2017 16:32:15 +0300 Subject: tcp_nv: fix division by zero in tcpnv_acked() 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 Patches currently in stable-queue which might be from khlebnikov@yandex-team.ru are queue-4.9/tcp_nv-fix-division-by-zero-in-tcpnv_acked.patch