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Commit cdda8891 authored by bingtian.ly@taobao.com's avatar bingtian.ly@taobao.com Committed by David S. Miller
Browse files

net: avoid to hang up on sending due to sysctl configuration overflow. 



    I found if we write a larger than 4GB value to some sysctl
variables, the sending syscall will hang up forever, because these
variables are 32 bits, such large values make them overflow to 0 or
negative.

    This patch try to fix overflow or prevent from zero value setup
of below sysctl variables:

net.core.wmem_default
net.core.rmem_default

net.core.rmem_max
net.core.wmem_max

net.ipv4.udp_rmem_min
net.ipv4.udp_wmem_min

net.ipv4.tcp_wmem
net.ipv4.tcp_rmem

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarLi Yu <raise.sail@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f7b5d1b9

net/core/sysctl_net_core.c

+10 −4
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 
#include <net/sock.h>

#include <net/net_ratelimit.h>



static int one = 1;



#ifdef CONFIG_RPS

static int rps_sock_flow_sysctl(ctl_table *table, int write,

				void __user *buffer, size_t *lenp, loff_t *ppos)
@@ -92,28 +94,32 @@ static struct ctl_table net_core_table[] = { 
		.data		= &sysctl_wmem_max,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= proc_dointvec

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= &one,

	},

	{

		.procname	= "rmem_max",

		.data		= &sysctl_rmem_max,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= proc_dointvec

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= &one,

	},

	{

		.procname	= "wmem_default",

		.data		= &sysctl_wmem_default,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= proc_dointvec

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= &one,

	},

	{

		.procname	= "rmem_default",

		.data		= &sysctl_rmem_default,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= proc_dointvec

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= &one,

	},

	{

		.procname	= "dev_weight",

net/ipv4/sysctl_net_ipv4.c

+7 −4
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <net/tcp_memcontrol.h>



static int zero;

static int one = 1;

static int two = 2;

static int tcp_retr1_max = 255;

static int ip_local_port_range_min[] = { 1, 1 };
@@ -549,14 +550,16 @@ static struct ctl_table ipv4_table[] = { 
		.data		= &sysctl_tcp_wmem,

		.maxlen		= sizeof(sysctl_tcp_wmem),

		.mode		= 0644,

		.proc_handler	= proc_dointvec

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= &one,

	},

	{

		.procname	= "tcp_rmem",

		.data		= &sysctl_tcp_rmem,

		.maxlen		= sizeof(sysctl_tcp_rmem),

		.mode		= 0644,

		.proc_handler	= proc_dointvec

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= &one,

	},

	{

		.procname	= "tcp_app_win",
@@ -779,7 +782,7 @@ static struct ctl_table ipv4_table[] = { 
		.maxlen		= sizeof(sysctl_udp_rmem_min),

		.mode		= 0644,

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= &zero

		.extra1		= &one

	},

	{

		.procname	= "udp_wmem_min",
@@ -787,7 +790,7 @@ static struct ctl_table ipv4_table[] = { 
		.maxlen		= sizeof(sysctl_udp_wmem_min),

		.mode		= 0644,

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= &zero

		.extra1		= &one

	},

	{ }

};