From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59892 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754475AbeDIUFH (ORCPT ); Mon, 9 Apr 2018 16:05:07 -0400 Subject: Patch "net: move somaxconn init from sysctl code" has been added to the 4.9-stable tree To: roman.kapl@sysgo.com, alexander.levin@microsoft.com, davem@davemloft.net, gregkh@linuxfoundation.org Cc: , From: Date: Mon, 09 Apr 2018 21:59:00 +0200 Message-ID: <152330394022154@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 net: move somaxconn init from sysctl code 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: net-move-somaxconn-init-from-sysctl-code.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 Mon Apr 9 17:09:24 CEST 2018 From: Roman Kapl Date: Wed, 24 May 2017 10:22:22 +0200 Subject: net: move somaxconn init from sysctl code From: Roman Kapl [ Upstream commit 7c3f1875c66fbc19762760097cabc91849ea0bbb ] The default value for somaxconn is set in sysctl_core_net_init(), but this function is not called when kernel is configured without CONFIG_SYSCTL. This results in the kernel not being able to accept TCP connections, because the backlog has zero size. Usually, the user ends up with: "TCP: request_sock_TCP: Possible SYN flooding on port 7. Dropping request. Check SNMP counters." If SYN cookies are not enabled the connection is rejected. Before ef547f2ac16 (tcp: remove max_qlen_log), the effects were less severe, because the backlog was always at least eight slots long. Signed-off-by: Roman Kapl Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/core/net_namespace.c | 19 +++++++++++++++++++ net/core/sysctl_net_core.c | 2 -- 2 files changed, 19 insertions(+), 2 deletions(-) --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -312,6 +312,25 @@ out_undo: goto out; } +static int __net_init net_defaults_init_net(struct net *net) +{ + net->core.sysctl_somaxconn = SOMAXCONN; + return 0; +} + +static struct pernet_operations net_defaults_ops = { + .init = net_defaults_init_net, +}; + +static __init int net_defaults_init(void) +{ + if (register_pernet_subsys(&net_defaults_ops)) + panic("Cannot initialize net default settings"); + + return 0; +} + +core_initcall(net_defaults_init); #ifdef CONFIG_NET_NS static struct ucounts *inc_net_namespaces(struct user_namespace *ns) --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -438,8 +438,6 @@ static __net_init int sysctl_core_net_in { struct ctl_table *tbl; - net->core.sysctl_somaxconn = SOMAXCONN; - tbl = netns_core_table; if (!net_eq(net, &init_net)) { tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL); Patches currently in stable-queue which might be from roman.kapl@sysgo.com are queue-4.9/net-move-somaxconn-init-from-sysctl-code.patch