diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 09a1f92..901bfe3 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -129,6 +129,11 @@ out:
 	return err;
 }
 
+
+typedef int proc_handler_extended(struct ctl_table *ctl, int write,
+				  void __user *buffer, size_t *lenp, loff_t *ppos,
+				  struct file *filp);
+
 static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf,
 		size_t count, loff_t *ppos, int write)
 {
@@ -137,6 +142,7 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf,
 	struct ctl_table *table = PROC_I(inode)->sysctl_entry;
 	ssize_t error;
 	size_t res;
+	proc_handler_extended *phx = (proc_handler_extended *) table->proc_handler;
 
 	if (IS_ERR(head))
 		return PTR_ERR(head);
@@ -156,7 +162,10 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf,
 
 	/* careful: calling conventions are nasty here */
 	res = count;
-	error = table->proc_handler(table, write, buf, &res, ppos);
+	/* most handlers only use the first 5 arguments (without @filp).
+	 * Changing all is too much of work, as, at the time of writting only
+	 * one proc_handler knows about and uses the @filp. */
+	error = phx(table, write, buf, &res, ppos, filp);
 	if (!error)
 		error = res;
 out:
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index ae8fdc5..abe2e25 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -43,8 +43,20 @@ enum
 
 #define IPV4_DEVCONF_MAX (__IPV4_DEVCONF_MAX - 1)
 
+
+struct devinet_sysctl {
+	/*
+	 * dev_name holds a copy of dev_name, because '.procname' is regarded as const
+	 * by sysctl and we wouldn't want anyone to change it under our feet
+	 * (see SIOCSIFNAME).
+	 */
+	char *dev_name;
+	struct ctl_table_header *sysctl_header;
+};
+
+
 struct ipv4_devconf {
-	void	*sysctl;
+	struct devinet_sysctl devinet_sysctl;
 	int	data[IPV4_DEVCONF_MAX];
 	DECLARE_BITMAP(state, IPV4_DEVCONF_MAX);
 };
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index d68c3f1..5210215 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -7,6 +7,7 @@
 
 #include <net/inet_frag.h>
 
+struct ctl_table;
 struct ctl_table_header;
 struct ipv4_devconf;
 struct fib_rules_ops;
@@ -19,6 +20,19 @@ struct netns_ipv4 {
 	struct ctl_table_header	*frags_hdr;
 	struct ctl_table_header	*ipv4_hdr;
 	struct ctl_table_header *route_hdr;
+	/* This holds the contents of /proc/sys/net/ipv4/conf/$DEV_NAME/
+	 *
+	 * The devinet_sysctl_table is shared by all network devices
+	 * in the same network namespace, but each network namespace
+	 * needs it's own copy of the table (the ->extra2 member of
+	 * each ctl_table must point to the corresponding 'struct net*').
+	 *
+	 * The ->data member is not used as defined in this table. The
+	 * proc_handler determines the apropiate data location based
+	 * on the 'struct net_device*' having the same name as
+	 * $DEV_NAME above.
+	 */
+	struct ctl_table	*devinet_sysctl_table;
 #endif
 	struct ipv4_devconf	*devconf_all;
 	struct ipv4_devconf	*devconf_dflt;
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 748cb5b..d03dfdc 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -158,7 +158,8 @@ static struct in_device *inetdev_init(struct net_device *dev)
 		goto out;
 	memcpy(&in_dev->cnf, dev_net(dev)->ipv4.devconf_dflt,
 			sizeof(in_dev->cnf));
-	in_dev->cnf.sysctl = NULL;
+	in_dev->cnf.devinet_sysctl.dev_name = NULL;
+	in_dev->cnf.devinet_sysctl.sysctl_header = NULL;
 	in_dev->dev = dev;
 	in_dev->arp_parms = neigh_parms_alloc(dev, &arp_tbl);
 	if (!in_dev->arp_parms)
@@ -1375,9 +1376,56 @@ static void inet_forward_change(struct net *net)
 	}
 }
 
-static int devinet_conf_proc(ctl_table *ctl, int write,
-			     void __user *buffer,
-			     size_t *lenp, loff_t *ppos)
+
+
+static int devinet_conf_handler(ctl_table *ctl, int write,
+				void __user *buffer,
+				size_t *lenp, loff_t *ppos,
+				struct file *filp,
+				proc_handler *proc_handler)
+{
+	/* The path to this file is of the form /proc/sys/net/ipv4/conf/$DEVNAME/$CTL
+	 *
+	 * To save space, ctl_table is shared between all network
+	 * devices in the same network namespace, but we need to
+	 * change the data corresponding to the $DEVNAME network
+	 * device, not any other's.
+	 *
+	 * Use $DEVNAME to obtain the coresponding ipv4_devconf.
+	 */
+	struct net *net = ctl->extra2;
+	const char *dev_name = filp->f_path.dentry->d_parent->d_name.name;
+	struct ctl_table tmp_ctl = *ctl;
+	struct net_device *dev = NULL;
+	struct ipv4_devconf *cnf;
+	int ret;
+
+	if (strcmp(dev_name, "all") == 0) {
+		cnf = net->ipv4.devconf_all;
+	} else if (strcmp(dev_name, "default") == 0) {
+		cnf = net->ipv4.devconf_dflt;
+	} else {
+		/* the device could have been renamed (SIOCSIFADDR) or
+		 * deleted since we started accessing it's proc sysctl */
+		dev = dev_get_by_name(net, dev_name);
+		if (dev == NULL)
+			return -ENOENT;
+		cnf = &in_dev_get(dev)->cnf;
+	}
+
+	tmp_ctl.data += (char *)cnf - (char *)&ipv4_devconf;
+	tmp_ctl.extra1 = cnf;
+
+	ret = proc_handler(&tmp_ctl, write, buffer, lenp, ppos);
+
+	if (dev)
+		dev_put(dev);
+	return ret;
+}
+
+static int __devinet_conf_proc(ctl_table *ctl, int write,
+			       void __user *buffer,
+			       size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
 
@@ -1395,9 +1443,9 @@ static int devinet_conf_proc(ctl_table *ctl, int write,
 	return ret;
 }
 
-static int devinet_sysctl_forward(ctl_table *ctl, int write,
-				  void __user *buffer,
-				  size_t *lenp, loff_t *ppos)
+static int __devinet_sysctl_forward(ctl_table *ctl, int write,
+				    void __user *buffer,
+				    size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
@@ -1430,9 +1478,10 @@ static int devinet_sysctl_forward(ctl_table *ctl, int write,
 	return ret;
 }
 
-static int ipv4_doint_and_flush(ctl_table *ctl, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+
+static int __ipv4_doint_and_flush(ctl_table *ctl, int write,
+				  void __user *buffer,
+				  size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
@@ -1445,6 +1494,33 @@ static int ipv4_doint_and_flush(ctl_table *ctl, int write,
 	return ret;
 }
 
+static int devinet_conf_proc(ctl_table *ctl, int write,
+			     void __user *buffer,
+			     size_t *lenp, loff_t *ppos,
+			     struct file *filp)
+{
+	return devinet_conf_handler(ctl, write, buffer, lenp, ppos, filp,
+				    __devinet_conf_proc);
+}
+
+static int devinet_sysctl_forward(ctl_table *ctl, int write,
+				  void __user *buffer,
+				  size_t *lenp, loff_t *ppos,
+				  struct file *filp)
+{
+	return devinet_conf_handler(ctl, write, buffer, lenp, ppos, filp,
+				    __devinet_sysctl_forward);
+}
+
+static int ipv4_doint_and_flush(ctl_table *ctl, int write,
+				void __user *buffer,
+				size_t *lenp, loff_t *ppos,
+				struct file *filp)
+{
+	return devinet_conf_handler(ctl, write, buffer, lenp, ppos, filp,
+				    __ipv4_doint_and_flush);
+}
+
 #define DEVINET_SYSCTL_ENTRY(attr, name, mval, proc) \
 	{ \
 		.procname	= name, \
@@ -1454,6 +1530,7 @@ static int ipv4_doint_and_flush(ctl_table *ctl, int write,
 		.mode		= mval, \
 		.proc_handler	= proc, \
 		.extra1		= &ipv4_devconf, \
+		.extra2		= &init_net, \
 	}
 
 #define DEVINET_SYSCTL_RW_ENTRY(attr, name) \
@@ -1468,51 +1545,45 @@ static int ipv4_doint_and_flush(ctl_table *ctl, int write,
 #define DEVINET_SYSCTL_FLUSHING_ENTRY(attr, name) \
 	DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, ipv4_doint_and_flush)
 
-static struct devinet_sysctl_table {
-	struct ctl_table_header *sysctl_header;
-	struct ctl_table devinet_vars[__IPV4_DEVCONF_MAX];
-	char *dev_name;
-} devinet_sysctl = {
-	.devinet_vars = {
-		DEVINET_SYSCTL_COMPLEX_ENTRY(FORWARDING, "forwarding",
-					     devinet_sysctl_forward),
-		DEVINET_SYSCTL_RO_ENTRY(MC_FORWARDING, "mc_forwarding"),
-
-		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_REDIRECTS, "accept_redirects"),
-		DEVINET_SYSCTL_RW_ENTRY(SECURE_REDIRECTS, "secure_redirects"),
-		DEVINET_SYSCTL_RW_ENTRY(SHARED_MEDIA, "shared_media"),
-		DEVINET_SYSCTL_RW_ENTRY(RP_FILTER, "rp_filter"),
-		DEVINET_SYSCTL_RW_ENTRY(SEND_REDIRECTS, "send_redirects"),
-		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_SOURCE_ROUTE,
-					"accept_source_route"),
-		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_LOCAL, "accept_local"),
-		DEVINET_SYSCTL_RW_ENTRY(SRC_VMARK, "src_valid_mark"),
-		DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP, "proxy_arp"),
-		DEVINET_SYSCTL_RW_ENTRY(MEDIUM_ID, "medium_id"),
-		DEVINET_SYSCTL_RW_ENTRY(BOOTP_RELAY, "bootp_relay"),
-		DEVINET_SYSCTL_RW_ENTRY(LOG_MARTIANS, "log_martians"),
-		DEVINET_SYSCTL_RW_ENTRY(TAG, "tag"),
-		DEVINET_SYSCTL_RW_ENTRY(ARPFILTER, "arp_filter"),
-		DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"),
-		DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),
-		DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"),
-		DEVINET_SYSCTL_RW_ENTRY(ARP_NOTIFY, "arp_notify"),
-		DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP_PVLAN, "proxy_arp_pvlan"),
-
-		DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"),
-		DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"),
-		DEVINET_SYSCTL_FLUSHING_ENTRY(FORCE_IGMP_VERSION,
-					      "force_igmp_version"),
-		DEVINET_SYSCTL_FLUSHING_ENTRY(PROMOTE_SECONDARIES,
-					      "promote_secondaries"),
-	},
+struct ctl_table ipv4_devinet_sysctl_table[__IPV4_DEVCONF_MAX] = {
+	DEVINET_SYSCTL_COMPLEX_ENTRY(FORWARDING, "forwarding",
+				     devinet_sysctl_forward),
+	DEVINET_SYSCTL_RO_ENTRY(MC_FORWARDING, "mc_forwarding"),
+
+	DEVINET_SYSCTL_RW_ENTRY(ACCEPT_REDIRECTS, "accept_redirects"),
+	DEVINET_SYSCTL_RW_ENTRY(SECURE_REDIRECTS, "secure_redirects"),
+	DEVINET_SYSCTL_RW_ENTRY(SHARED_MEDIA, "shared_media"),
+	DEVINET_SYSCTL_RW_ENTRY(RP_FILTER, "rp_filter"),
+	DEVINET_SYSCTL_RW_ENTRY(SEND_REDIRECTS, "send_redirects"),
+	DEVINET_SYSCTL_RW_ENTRY(ACCEPT_SOURCE_ROUTE,
+				"accept_source_route"),
+	DEVINET_SYSCTL_RW_ENTRY(ACCEPT_LOCAL, "accept_local"),
+	DEVINET_SYSCTL_RW_ENTRY(SRC_VMARK, "src_valid_mark"),
+	DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP, "proxy_arp"),
+	DEVINET_SYSCTL_RW_ENTRY(MEDIUM_ID, "medium_id"),
+	DEVINET_SYSCTL_RW_ENTRY(BOOTP_RELAY, "bootp_relay"),
+	DEVINET_SYSCTL_RW_ENTRY(LOG_MARTIANS, "log_martians"),
+	DEVINET_SYSCTL_RW_ENTRY(TAG, "tag"),
+	DEVINET_SYSCTL_RW_ENTRY(ARPFILTER, "arp_filter"),
+	DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"),
+	DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),
+	DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"),
+	DEVINET_SYSCTL_RW_ENTRY(ARP_NOTIFY, "arp_notify"),
+	DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP_PVLAN, "proxy_arp_pvlan"),
+
+	DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"),
+	DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"),
+	DEVINET_SYSCTL_FLUSHING_ENTRY(FORCE_IGMP_VERSION,
+				      "force_igmp_version"),
+	DEVINET_SYSCTL_FLUSHING_ENTRY(PROMOTE_SECONDARIES,
+				      "promote_secondaries"),
+	{ }
 };
 
 static int __devinet_sysctl_register(struct net *net, char *dev_name,
-					struct ipv4_devconf *p)
+				     struct ipv4_devconf *cnf)
 {
-	int i;
-	struct devinet_sysctl_table *t;
+	struct devinet_sysctl *dsys = &cnf->devinet_sysctl;
 
 #define DEVINET_CTL_PATH_DEV	3
 
@@ -1524,54 +1595,42 @@ static int __devinet_sysctl_register(struct net *net, char *dev_name,
 		{ },
 	};
 
-	t = kmemdup(&devinet_sysctl, sizeof(*t), GFP_KERNEL);
-	if (!t)
-		goto out;
-
-	for (i = 0; i < ARRAY_SIZE(t->devinet_vars) - 1; i++) {
-		t->devinet_vars[i].data += (char *)p - (char *)&ipv4_devconf;
-		t->devinet_vars[i].extra1 = p;
-		t->devinet_vars[i].extra2 = net;
-	}
-
 	/*
 	 * Make a copy of dev_name, because '.procname' is regarded as const
 	 * by sysctl and we wouldn't want anyone to change it under our feet
 	 * (see SIOCSIFNAME).
 	 */
-	t->dev_name = kstrdup(dev_name, GFP_KERNEL);
-	if (!t->dev_name)
-		goto free;
+	dsys->dev_name = kstrdup(dev_name, GFP_KERNEL);
+	if (!dsys->dev_name)
+		goto out;
 
-	devinet_ctl_path[DEVINET_CTL_PATH_DEV].procname = t->dev_name;
+	devinet_ctl_path[DEVINET_CTL_PATH_DEV].procname = dsys->dev_name;
 
-	t->sysctl_header = register_net_sysctl_table(net, devinet_ctl_path,
-			t->devinet_vars);
-	if (!t->sysctl_header)
+	dsys->sysctl_header = register_net_sysctl_table(net, devinet_ctl_path,
+						net->ipv4.devinet_sysctl_table);
+	if (!dsys->sysctl_header)
 		goto free_procname;
 
-	p->sysctl = t;
 	return 0;
 
 free_procname:
-	kfree(t->dev_name);
-free:
-	kfree(t);
+	kfree(dsys->dev_name);
 out:
 	return -ENOBUFS;
 }
 
 static void __devinet_sysctl_unregister(struct ipv4_devconf *cnf)
 {
-	struct devinet_sysctl_table *t = cnf->sysctl;
+	struct devinet_sysctl *dsys = &cnf->devinet_sysctl;
 
-	if (t == NULL)
+	if (dsys == NULL)
 		return;
 
-	cnf->sysctl = NULL;
-	unregister_sysctl_table(t->sysctl_header);
-	kfree(t->dev_name);
-	kfree(t);
+	unregister_sysctl_table(dsys->sysctl_header);
+	kfree(dsys->dev_name);
+
+	dsys->dev_name = NULL;
+	dsys->sysctl_header = NULL;
 }
 
 static void devinet_sysctl_register(struct in_device *idev)
@@ -1610,9 +1669,10 @@ static __net_initdata struct ctl_path net_ipv4_path[] = {
 
 static __net_init int devinet_init_net(struct net *net)
 {
-	int err;
+	int i, err;
 	struct ipv4_devconf *all, *dflt;
 #ifdef CONFIG_SYSCTL
+	struct ctl_table *devinet_sysctl_table;
 	struct ctl_table *tbl = ctl_forward_entry;
 	struct ctl_table_header *forw_hdr;
 #endif
@@ -1620,6 +1680,7 @@ static __net_init int devinet_init_net(struct net *net)
 	err = -ENOMEM;
 	all = &ipv4_devconf;
 	dflt = &ipv4_devconf_dflt;
+	devinet_sysctl_table = &ipv4_devinet_sysctl_table[0];
 
 	if (!net_eq(net, &init_net)) {
 		all = kmemdup(all, sizeof(ipv4_devconf), GFP_KERNEL);
@@ -1638,10 +1699,23 @@ static __net_init int devinet_init_net(struct net *net)
 		tbl[0].data = &all->data[IPV4_DEVCONF_FORWARDING - 1];
 		tbl[0].extra1 = all;
 		tbl[0].extra2 = net;
+
+		devinet_sysctl_table = kmemdup(ipv4_devinet_sysctl_table,
+					       sizeof(ipv4_devinet_sysctl_table),
+					       GFP_KERNEL);
+		if (devinet_sysctl_table == NULL)
+			goto err_alloc_devinet_sysctl_table;
+
+		/* the last element in the table is { } and must remain so */
+		for (i = 0; i < ARRAY_SIZE(ipv4_devinet_sysctl_table) - 1; i++) {
+			devinet_sysctl_table->extra2 = net;
+		}
 #endif
 	}
 
 #ifdef CONFIG_SYSCTL
+	net->ipv4.devinet_sysctl_table = devinet_sysctl_table;
+
 	err = __devinet_sysctl_register(net, "all", all);
 	if (err < 0)
 		goto err_reg_all;
@@ -1667,6 +1741,9 @@ err_reg_ctl:
 err_reg_dflt:
 	__devinet_sysctl_unregister(all);
 err_reg_all:
+	if (devinet_sysctl_table != &ipv4_devinet_sysctl_table[0])
+		kfree(devinet_sysctl_table);
+err_alloc_devinet_sysctl_table:
 	if (tbl != ctl_forward_entry)
 		kfree(tbl);
 err_alloc_ctl:
@@ -1689,6 +1766,7 @@ static __net_exit void devinet_exit_net(struct net *net)
 	unregister_net_sysctl_table(net->ipv4.forw_hdr);
 	__devinet_sysctl_unregister(net->ipv4.devconf_dflt);
 	__devinet_sysctl_unregister(net->ipv4.devconf_all);
+	kfree(net->ipv4.devinet_sysctl_table);
 	kfree(tbl);
 #endif
 	kfree(net->ipv4.devconf_dflt);