From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58072 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752724AbeDJJG4 (ORCPT ); Tue, 10 Apr 2018 05:06:56 -0400 Subject: Patch "net: move somaxconn init from sysctl code" has been added to the 4.4-stable tree To: roman.kapl@sysgo.com, alexander.levin@microsoft.com, davem@davemloft.net, gregkh@linuxfoundation.org Cc: , From: Date: Tue, 10 Apr 2018 11:05:09 +0200 Message-ID: <1523351109111191@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 4.4-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-4.4 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 Apr 10 10:31:53 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 @@ -310,6 +310,25 @@ 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 kmem_cache *net_cachep; --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -429,8 +429,6 @@ 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-4.4/net-move-somaxconn-init-from-sysctl-code.patch