Merge branch 'net-improve-netns-handling-in-rtnetlink'

Xiao Liang says:

====================
net: Improve netns handling in rtnetlink

This patch series includes some netns-related improvements and fixes for
rtnetlink, to make link creation more intuitive:

 1) Creating link in another net namespace doesn't conflict with link
    names in current one.
 2) Refector rtnetlink link creation. Create link in target namespace
    directly.

So that

  # ip link add netns ns1 link-netns ns2 tun0 type gre ...

will create tun0 in ns1, rather than create it in ns2 and move to ns1.
And don't conflict with another interface named "tun0" in current netns.

Patch 01 avoids link name conflict in different netns.

To achieve 2), there're mainly 3 steps:

 - Patch 02 packs newlink() parameters into a struct, including
   the original "src_net" along with more netns context. No semantic
   changes are introduced.
 - Patch 03 ~ 09 converts device drivers to use the explicit netns
   extracted from params.
 - Patch 10 ~ 11 removes the old netns parameter, and converts
   rtnetlink to create device in target netns directly.

Patch 12 ~ 13 adds some tests for link name and link netns.

---

Please note there're some issues found in current code:

- In amt_newlink() drivers/net/amt.c:

    amt->net = net;
    ...
    amt->stream_dev = dev_get_by_index(net, ...

  Uses net, but amt_lookup_upper_dev() only searches in dev_net.
  So the AMT device may not be properly deleted if it's in a different
  netns from lower dev.

- In lowpan_newlink() in net/ieee802154/6lowpan/core.c:

    wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK]));

  Looks for IFLA_LINK in dev_net, but in theory the ifindex is defined
  in link netns.

And thanks to Kuniyuki for fixing related issues in gtp and pfcp:
https://lore.kernel.org/netdev/20250110014754.33847-1-kuniyu@amazon.com/

v9: https://lore.kernel.org/20250210133002.883422-1-shaw.leon@gmail.com
v8: https://lore.kernel.org/20250113143719.7948-1-shaw.leon@gmail.com
v7: https://lore.kernel.org/20250104125732.17335-1-shaw.leon@gmail.com
v6: https://lore.kernel.org/20241218130909.2173-1-shaw.leon@gmail.com
v5: https://lore.kernel.org/20241209140151.231257-1-shaw.leon@gmail.com
v4: https://lore.kernel.org/20241118143244.1773-1-shaw.leon@gmail.com
v3: https://lore.kernel.org/20241113125715.150201-1-shaw.leon@gmail.com
v2: https://lore.kernel.org/20241107133004.7469-1-shaw.leon@gmail.com
v1: https://lore.kernel.org/20241023023146.372653-1-shaw.leon@gmail.com
====================

Link: https://patch.msgid.link/20250219125039.18024-1-shaw.leon@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

16 files changed, 130 insertions, 92 deletions

diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c
index 134419667d59..a000b1ef0520 100644
--- a/net/8021q/vlan_netlink.c
+++ b/net/8021q/vlan_netlink.c
@@ -135,11 +135,14 @@ static int vlan_changelink(struct net_device *dev, struct nlattr *tb[],
 	return 0;
 }
 
-static int vlan_newlink(struct net *src_net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
+static int vlan_newlink(struct net_device *dev,
+			struct rtnl_newlink_params *params,
 			struct netlink_ext_ack *extack)
 {
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
 	struct net_device *real_dev;
 	unsigned int max_mtu;
 	__be16 proto;
@@ -155,7 +158,7 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev,
 		return -EINVAL;
 	}
 
-	real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
+	real_dev = __dev_get_by_index(link_net, nla_get_u32(tb[IFLA_LINK]));
 	if (!real_dev) {
 		NL_SET_ERR_MSG_MOD(extack, "link does not exist");
 		return -ENODEV;
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 822d788a5f86..d893c8013261 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -1077,19 +1077,18 @@ static int batadv_softif_validate(struct nlattr *tb[], struct nlattr *data[],
 
 /**
  * batadv_softif_newlink() - pre-initialize and register new batadv link
- * @src_net: the applicable net namespace
  * @dev: network device to register
- * @tb: IFLA_INFO_DATA netlink attributes
- * @data: enum batadv_ifla_attrs attributes
+ * @params: rtnl newlink parameters
  * @extack: extended ACK report struct
  *
  * Return: 0 if successful or error otherwise.
  */
-static int batadv_softif_newlink(struct net *src_net, struct net_device *dev,
-				 struct nlattr *tb[], struct nlattr *data[],
+static int batadv_softif_newlink(struct net_device *dev,
+				 struct rtnl_newlink_params *params,
 				 struct netlink_ext_ack *extack)
 {
 	struct batadv_priv *bat_priv = netdev_priv(dev);
+	struct nlattr **data = params->data;
 	const char *algo_name;
 	int err;
 
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 3e0f47203f2a..6e337937d0d7 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1553,11 +1553,13 @@ static int br_changelink(struct net_device *brdev, struct nlattr *tb[],
 	return 0;
 }
 
-static int br_dev_newlink(struct net *src_net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
+static int br_dev_newlink(struct net_device *dev,
+			  struct rtnl_newlink_params *params,
 			  struct netlink_ext_ack *extack)
 {
 	struct net_bridge *br = netdev_priv(dev);
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
 	int err;
 
 	err = register_netdevice(dev);
diff --git a/net/caif/chnl_net.c b/net/caif/chnl_net.c
index 94ad09e36df2..fa6a3c2634a8 100644
--- a/net/caif/chnl_net.c
+++ b/net/caif/chnl_net.c
@@ -438,10 +438,11 @@ static void caif_netlink_parms(struct nlattr *data[],
 	}
 }
 
-static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
+static int ipcaif_newlink(struct net_device *dev,
+			  struct rtnl_newlink_params *params,
 			  struct netlink_ext_ack *extack)
 {
+	struct nlattr **data = params->data;
 	int ret;
 	struct chnl_net *caifdev;
 	ASSERT_RTNL();
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index abe1a461ea67..b52e610e157e 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3767,7 +3767,13 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
 			       struct netlink_ext_ack *extack)
 {
 	unsigned char name_assign_type = NET_NAME_USER;
-	struct net *net = sock_net(skb->sk);
+	struct rtnl_newlink_params params = {
+		.src_net = sock_net(skb->sk),
+		.link_net = link_net,
+		.peer_net = peer_net,
+		.tb = tb,
+		.data = data,
+	};
 	u32 portid = NETLINK_CB(skb).portid;
 	struct net_device *dev;
 	char ifname[IFNAMSIZ];
@@ -3783,8 +3789,8 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
 		name_assign_type = NET_NAME_ENUM;
 	}
 
-	dev = rtnl_create_link(link_net ? : tgt_net, ifname,
-			       name_assign_type, ops, tb, extack);
+	dev = rtnl_create_link(tgt_net, ifname, name_assign_type, ops, tb,
+			       extack);
 	if (IS_ERR(dev)) {
 		err = PTR_ERR(dev);
 		goto out;
@@ -3792,13 +3798,8 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
 
 	dev->ifindex = ifm->ifi_index;
 
-	if (link_net)
-		net = link_net;
-	if (peer_net)
-		net = peer_net;
-
 	if (ops->newlink)
-		err = ops->newlink(net, dev, tb, data, extack);
+		err = ops->newlink(dev, &params, extack);
 	else
 		err = register_netdevice(dev);
 	if (err < 0) {
@@ -3809,11 +3810,6 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
 	err = rtnl_configure_link(dev, ifm, portid, nlh);
 	if (err < 0)
 		goto out_unregister;
-	if (link_net) {
-		err = dev_change_net_namespace(dev, tgt_net, ifname);
-		if (err < 0)
-			goto out_unregister;
-	}
 	if (tb[IFLA_MASTER]) {
 		err = do_set_master(dev, nla_get_u32(tb[IFLA_MASTER]), extack);
 		if (err)
@@ -3867,20 +3863,26 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
 {
 	struct nlattr ** const tb = tbs->tb;
 	struct net *net = sock_net(skb->sk);
+	struct net *device_net;
 	struct net_device *dev;
 	struct ifinfomsg *ifm;
 	bool link_specified;
 
+	/* When creating, lookup for existing device in target net namespace */
+	device_net = (nlh->nlmsg_flags & NLM_F_CREATE) &&
+		     (nlh->nlmsg_flags & NLM_F_EXCL) ?
+		     tgt_net : net;
+
 	ifm = nlmsg_data(nlh);
 	if (ifm->ifi_index > 0) {
 		link_specified = true;
-		dev = __dev_get_by_index(net, ifm->ifi_index);
+		dev = __dev_get_by_index(device_net, ifm->ifi_index);
 	} else if (ifm->ifi_index < 0) {
 		NL_SET_ERR_MSG(extack, "ifindex can't be negative");
 		return -EINVAL;
 	} else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME]) {
 		link_specified = true;
-		dev = rtnl_dev_get(net, tb);
+		dev = rtnl_dev_get(device_net, tb);
 	} else {
 		link_specified = false;
 		dev = NULL;
diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c
index b68f2f71d0e1..b120470246cc 100644
--- a/net/hsr/hsr_netlink.c
+++ b/net/hsr/hsr_netlink.c
@@ -29,10 +29,12 @@ static const struct nla_policy hsr_policy[IFLA_HSR_MAX + 1] = {
 /* Here, it seems a netdevice has already been allocated for us, and the
  * hsr_dev_setup routine has been executed. Nice!
  */
-static int hsr_newlink(struct net *src_net, struct net_device *dev,
-		       struct nlattr *tb[], struct nlattr *data[],
+static int hsr_newlink(struct net_device *dev,
+		       struct rtnl_newlink_params *params,
 		       struct netlink_ext_ack *extack)
 {
+	struct net *link_net = rtnl_newlink_link_net(params);
+	struct nlattr **data = params->data;
 	enum hsr_version proto_version;
 	unsigned char multicast_spec;
 	u8 proto = HSR_PROTOCOL_HSR;
@@ -46,7 +48,7 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev,
 		NL_SET_ERR_MSG_MOD(extack, "Slave1 device not specified");
 		return -EINVAL;
 	}
-	link[0] = __dev_get_by_index(src_net,
+	link[0] = __dev_get_by_index(link_net,
 				     nla_get_u32(data[IFLA_HSR_SLAVE1]));
 	if (!link[0]) {
 		NL_SET_ERR_MSG_MOD(extack, "Slave1 does not exist");
@@ -56,7 +58,7 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev,
 		NL_SET_ERR_MSG_MOD(extack, "Slave2 device not specified");
 		return -EINVAL;
 	}
-	link[1] = __dev_get_by_index(src_net,
+	link[1] = __dev_get_by_index(link_net,
 				     nla_get_u32(data[IFLA_HSR_SLAVE2]));
 	if (!link[1]) {
 		NL_SET_ERR_MSG_MOD(extack, "Slave2 does not exist");
@@ -69,7 +71,7 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev,
 	}
 
 	if (data[IFLA_HSR_INTERLINK])
-		interlink = __dev_get_by_index(src_net,
+		interlink = __dev_get_by_index(link_net,
 					       nla_get_u32(data[IFLA_HSR_INTERLINK]));
 
 	if (interlink && interlink == link[0]) {
diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c
index 175efd860f7b..ee318d46817d 100644
--- a/net/ieee802154/6lowpan/core.c
+++ b/net/ieee802154/6lowpan/core.c
@@ -129,10 +129,11 @@ static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[],
 	return 0;
 }
 
-static int lowpan_newlink(struct net *src_net, struct net_device *ldev,
-			  struct nlattr *tb[], struct nlattr *data[],
+static int lowpan_newlink(struct net_device *ldev,
+			  struct rtnl_newlink_params *params,
 			  struct netlink_ext_ack *extack)
 {
+	struct nlattr **tb = params->tb;
 	struct net_device *wdev;
 	int ret;
 
@@ -142,6 +143,8 @@ static int lowpan_newlink(struct net *src_net, struct net_device *ldev,
 
 	if (!tb[IFLA_LINK])
 		return -EINVAL;
+	if (params->link_net && !net_eq(params->link_net, dev_net(ldev)))
+		return -EINVAL;
 	/* find and hold wpan device */
 	wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK]));
 	if (!wdev)
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index c9f11a046c26..26d15f907551 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1396,10 +1396,12 @@ ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[])
 	return 0;
 }
 
-static int ipgre_newlink(struct net *src_net, struct net_device *dev,
-			 struct nlattr *tb[], struct nlattr *data[],
+static int ipgre_newlink(struct net_device *dev,
+			 struct rtnl_newlink_params *params,
 			 struct netlink_ext_ack *extack)
 {
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
 	struct ip_tunnel_parm_kern p;
 	__u32 fwmark = 0;
 	int err;
@@ -1411,13 +1413,16 @@ static int ipgre_newlink(struct net *src_net, struct net_device *dev,
 	err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
 	if (err < 0)
 		return err;
-	return ip_tunnel_newlink(dev, tb, &p, fwmark);
+	return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p,
+				 fwmark);
 }
 
-static int erspan_newlink(struct net *src_net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
+static int erspan_newlink(struct net_device *dev,
+			  struct rtnl_newlink_params *params,
 			  struct netlink_ext_ack *extack)
 {
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
 	struct ip_tunnel_parm_kern p;
 	__u32 fwmark = 0;
 	int err;
@@ -1429,7 +1434,8 @@ static int erspan_newlink(struct net *src_net, struct net_device *dev,
 	err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
 	if (err)
 		return err;
-	return ip_tunnel_newlink(dev, tb, &p, fwmark);
+	return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p,
+				 fwmark);
 }
 
 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
@@ -1697,6 +1703,7 @@ static struct rtnl_link_ops erspan_link_ops __read_mostly = {
 struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 					u8 name_assign_type)
 {
+	struct rtnl_newlink_params params = { .src_net = net };
 	struct nlattr *tb[IFLA_MAX + 1];
 	struct net_device *dev;
 	LIST_HEAD(list_kill);
@@ -1704,6 +1711,7 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 	int err;
 
 	memset(&tb, 0, sizeof(tb));
+	params.tb = tb;
 
 	dev = rtnl_create_link(net, name, name_assign_type,
 			       &ipgre_tap_ops, tb, NULL);
@@ -1714,7 +1722,7 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 	t = netdev_priv(dev);
 	t->collect_md = true;
 
-	err = ipgre_newlink(net, dev, tb, NULL, NULL);
+	err = ipgre_newlink(dev, &params, NULL);
 	if (err < 0) {
 		free_netdev(dev);
 		return ERR_PTR(err);
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 09b73acf037a..011f2a5aab3b 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -1213,11 +1213,11 @@ void ip_tunnel_delete_nets(struct list_head *net_list, unsigned int id,
 }
 EXPORT_SYMBOL_GPL(ip_tunnel_delete_nets);
 
-int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
-		      struct ip_tunnel_parm_kern *p, __u32 fwmark)
+int ip_tunnel_newlink(struct net *net, struct net_device *dev,
+		      struct nlattr *tb[], struct ip_tunnel_parm_kern *p,
+		      __u32 fwmark)
 {
 	struct ip_tunnel *nt;
-	struct net *net = dev_net(dev);
 	struct ip_tunnel_net *itn;
 	int mtu;
 	int err;
@@ -1326,7 +1326,6 @@ int ip_tunnel_init(struct net_device *dev)
 	}
 
 	tunnel->dev = dev;
-	tunnel->net = dev_net(dev);
 	strscpy(tunnel->parms.name, dev->name);
 	iph->version		= 4;
 	iph->ihl		= 5;
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index f0b4419cef34..159b4473290e 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -575,15 +575,18 @@ static void vti_netlink_parms(struct nlattr *data[],
 		*fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
 }
 
-static int vti_newlink(struct net *src_net, struct net_device *dev,
-		       struct nlattr *tb[], struct nlattr *data[],
+static int vti_newlink(struct net_device *dev,
+		       struct rtnl_newlink_params *params,
 		       struct netlink_ext_ack *extack)
 {
+	struct nlattr **data = params->data;
 	struct ip_tunnel_parm_kern parms;
+	struct nlattr **tb = params->tb;
 	__u32 fwmark = 0;
 
 	vti_netlink_parms(data, &parms, &fwmark);
-	return ip_tunnel_newlink(dev, tb, &parms, fwmark);
+	return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb,
+				 &parms, fwmark);
 }
 
 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index dc0db5895e0e..bab0bf90c908 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -436,11 +436,13 @@ static void ipip_netlink_parms(struct nlattr *data[],
 		*fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
 }
 
-static int ipip_newlink(struct net *src_net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
+static int ipip_newlink(struct net_device *dev,
+			struct rtnl_newlink_params *params,
 			struct netlink_ext_ack *extack)
 {
 	struct ip_tunnel *t = netdev_priv(dev);
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
 	struct ip_tunnel_encap ipencap;
 	struct ip_tunnel_parm_kern p;
 	__u32 fwmark = 0;
@@ -453,7 +455,8 @@ static int ipip_newlink(struct net *src_net, struct net_device *dev,
 	}
 
 	ipip_netlink_parms(data, &p, &t->collect_md, &fwmark);
-	return ip_tunnel_newlink(dev, tb, &p, fwmark);
+	return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p,
+				 fwmark);
 }
 
 static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 235808cfec70..d31a4ce3b19f 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1498,7 +1498,6 @@ static int ip6gre_tunnel_init_common(struct net_device *dev)
 	tunnel = netdev_priv(dev);
 
 	tunnel->dev = dev;
-	tunnel->net = dev_net(dev);
 	strcpy(tunnel->parms.name, dev->name);
 
 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
@@ -1882,7 +1881,6 @@ static int ip6erspan_tap_init(struct net_device *dev)
 	tunnel = netdev_priv(dev);
 
 	tunnel->dev = dev;
-	tunnel->net = dev_net(dev);
 	strcpy(tunnel->parms.name, dev->name);
 
 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
@@ -1971,7 +1969,7 @@ static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
 	return ret;
 }
 
-static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
+static int ip6gre_newlink_common(struct net *link_net, struct net_device *dev,
 				 struct nlattr *tb[], struct nlattr *data[],
 				 struct netlink_ext_ack *extack)
 {
@@ -1992,7 +1990,7 @@ static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
 		eth_hw_addr_random(dev);
 
 	nt->dev = dev;
-	nt->net = dev_net(dev);
+	nt->net = link_net;
 
 	err = register_netdevice(dev);
 	if (err)
@@ -2005,12 +2003,14 @@ out:
 	return err;
 }
 
-static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
+static int ip6gre_newlink(struct net_device *dev,
+			  struct rtnl_newlink_params *params,
 			  struct netlink_ext_ack *extack)
 {
+	struct net *net = params->link_net ? : dev_net(dev);
 	struct ip6_tnl *nt = netdev_priv(dev);
-	struct net *net = dev_net(dev);
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
 	struct ip6gre_net *ign;
 	int err;
 
@@ -2025,7 +2025,7 @@ static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
 			return -EEXIST;
 	}
 
-	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
+	err = ip6gre_newlink_common(net, dev, tb, data, extack);
 	if (!err) {
 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
 		ip6gre_tunnel_link_md(ign, nt);
@@ -2241,12 +2241,14 @@ static void ip6erspan_tap_setup(struct net_device *dev)
 	netif_keep_dst(dev);
 }
 
-static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
-			     struct nlattr *tb[], struct nlattr *data[],
+static int ip6erspan_newlink(struct net_device *dev,
+			     struct rtnl_newlink_params *params,
 			     struct netlink_ext_ack *extack)
 {
+	struct net *net = params->link_net ? : dev_net(dev);
 	struct ip6_tnl *nt = netdev_priv(dev);
-	struct net *net = dev_net(dev);
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
 	struct ip6gre_net *ign;
 	int err;
 
@@ -2262,7 +2264,7 @@ static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
 			return -EEXIST;
 	}
 
-	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
+	err = ip6gre_newlink_common(net, dev, tb, data, extack);
 	if (!err) {
 		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
 		ip6erspan_tunnel_link_md(ign, nt);
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 48fd53b98972..89d206731af0 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -253,8 +253,7 @@ static void ip6_dev_free(struct net_device *dev)
 static int ip6_tnl_create2(struct net_device *dev)
 {
 	struct ip6_tnl *t = netdev_priv(dev);
-	struct net *net = dev_net(dev);
-	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
+	struct ip6_tnl_net *ip6n = net_generic(t->net, ip6_tnl_net_id);
 	int err;
 
 	dev->rtnl_link_ops = &ip6_link_ops;
@@ -1878,7 +1877,6 @@ ip6_tnl_dev_init_gen(struct net_device *dev)
 	int t_hlen;
 
 	t->dev = dev;
-	t->net = dev_net(dev);
 
 	ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
 	if (ret)
@@ -1940,6 +1938,7 @@ static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
 	struct net *net = dev_net(dev);
 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 
+	t->net = net;
 	t->parms.proto = IPPROTO_IPV6;
 
 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
@@ -2002,17 +2001,22 @@ static void ip6_tnl_netlink_parms(struct nlattr *data[],
 		parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
 }
 
-static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
-			   struct nlattr *tb[], struct nlattr *data[],
+static int ip6_tnl_newlink(struct net_device *dev,
+			   struct rtnl_newlink_params *params,
 			   struct netlink_ext_ack *extack)
 {
-	struct net *net = dev_net(dev);
-	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
 	struct ip_tunnel_encap ipencap;
+	struct ip6_tnl_net *ip6n;
 	struct ip6_tnl *nt, *t;
+	struct net *net;
 	int err;
 
+	net = params->link_net ? : dev_net(dev);
+	ip6n = net_generic(net, ip6_tnl_net_id);
 	nt = netdev_priv(dev);
+	nt->net = net;
 
 	if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
 		err = ip6_tnl_encap_setup(nt, &ipencap);
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 590737c27537..83c055996fbb 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -177,8 +177,7 @@ vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t)
 static int vti6_tnl_create2(struct net_device *dev)
 {
 	struct ip6_tnl *t = netdev_priv(dev);
-	struct net *net = dev_net(dev);
-	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+	struct vti6_net *ip6n = net_generic(t->net, vti6_net_id);
 	int err;
 
 	dev->rtnl_link_ops = &vti6_link_ops;
@@ -925,7 +924,6 @@ static inline int vti6_dev_init_gen(struct net_device *dev)
 	struct ip6_tnl *t = netdev_priv(dev);
 
 	t->dev = dev;
-	t->net = dev_net(dev);
 	netdev_hold(dev, &t->dev_tracker, GFP_KERNEL);
 	netdev_lockdep_set_classes(dev);
 	return 0;
@@ -958,6 +956,7 @@ static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev)
 	struct net *net = dev_net(dev);
 	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
 
+	t->net = net;
 	t->parms.proto = IPPROTO_IPV6;
 
 	rcu_assign_pointer(ip6n->tnls_wc[0], t);
@@ -997,17 +996,20 @@ static void vti6_netlink_parms(struct nlattr *data[],
 		parms->fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
 }
 
-static int vti6_newlink(struct net *src_net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
+static int vti6_newlink(struct net_device *dev,
+			struct rtnl_newlink_params *params,
 			struct netlink_ext_ack *extack)
 {
-	struct net *net = dev_net(dev);
+	struct nlattr **data = params->data;
 	struct ip6_tnl *nt;
+	struct net *net;
 
+	net = params->link_net ? : dev_net(dev);
 	nt = netdev_priv(dev);
 	vti6_netlink_parms(data, &nt->parms);
 
 	nt->parms.proto = IPPROTO_IPV6;
+	nt->net = net;
 
 	if (vti6_locate(net, &nt->parms, 0))
 		return -EEXIST;
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 39bd8951bfca..f7b59bc957d3 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -201,8 +201,7 @@ static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
 static int ipip6_tunnel_create(struct net_device *dev)
 {
 	struct ip_tunnel *t = netdev_priv(dev);
-	struct net *net = dev_net(dev);
-	struct sit_net *sitn = net_generic(net, sit_net_id);
+	struct sit_net *sitn = net_generic(t->net, sit_net_id);
 	int err;
 
 	__dev_addr_set(dev, &t->parms.iph.saddr, 4);
@@ -269,6 +268,7 @@ static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 
 	nt = netdev_priv(dev);
 
+	nt->net = net;
 	nt->parms = *parms;
 	if (ipip6_tunnel_create(dev) < 0)
 		goto failed_free;
@@ -1449,7 +1449,6 @@ static int ipip6_tunnel_init(struct net_device *dev)
 	int err;
 
 	tunnel->dev = dev;
-	tunnel->net = dev_net(dev);
 	strcpy(tunnel->parms.name, dev->name);
 
 	ipip6_tunnel_bind_dev(dev);
@@ -1550,19 +1549,23 @@ static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
 }
 #endif
 
-static int ipip6_newlink(struct net *src_net, struct net_device *dev,
-			 struct nlattr *tb[], struct nlattr *data[],
+static int ipip6_newlink(struct net_device *dev,
+			 struct rtnl_newlink_params *params,
 			 struct netlink_ext_ack *extack)
 {
-	struct net *net = dev_net(dev);
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
 	struct ip_tunnel *nt;
 	struct ip_tunnel_encap ipencap;
 #ifdef CONFIG_IPV6_SIT_6RD
 	struct ip_tunnel_6rd ip6rd;
 #endif
+	struct net *net;
 	int err;
 
+	net = params->link_net ? : dev_net(dev);
 	nt = netdev_priv(dev);
+	nt->net = net;
 
 	if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
 		err = ip_tunnel_encap_setup(nt, &ipencap);
@@ -1858,6 +1861,9 @@ static int __net_init sit_init_net(struct net *net)
 	 */
 	sitn->fb_tunnel_dev->netns_local = true;
 
+	t = netdev_priv(sitn->fb_tunnel_dev);
+	t->net = net;
+
 	err = register_netdev(sitn->fb_tunnel_dev);
 	if (err)
 		goto err_reg_dev;
@@ -1865,8 +1871,6 @@ static int __net_init sit_init_net(struct net *net)
 	ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
 	ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
 
-	t = netdev_priv(sitn->fb_tunnel_dev);
-
 	strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
 	return 0;
 
diff --git a/net/xfrm/xfrm_interface_core.c b/net/xfrm/xfrm_interface_core.c
index c397eb99d867..622445f041d3 100644
--- a/net/xfrm/xfrm_interface_core.c
+++ b/net/xfrm/xfrm_interface_core.c
@@ -242,10 +242,9 @@ static void xfrmi_dev_free(struct net_device *dev)
 	gro_cells_destroy(&xi->gro_cells);
 }
 
-static int xfrmi_create(struct net_device *dev)
+static int xfrmi_create(struct net *net, struct net_device *dev)
 {
 	struct xfrm_if *xi = netdev_priv(dev);
-	struct net *net = dev_net(dev);
 	struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id);
 	int err;
 
@@ -814,15 +813,17 @@ static void xfrmi_netlink_parms(struct nlattr *data[],
 		parms->collect_md = true;
 }
 
-static int xfrmi_newlink(struct net *src_net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
+static int xfrmi_newlink(struct net_device *dev,
+			 struct rtnl_newlink_params *params,
+			 struct netlink_ext_ack *extack)
 {
-	struct net *net = dev_net(dev);
+	struct nlattr **data = params->data;
 	struct xfrm_if_parms p = {};
 	struct xfrm_if *xi;
+	struct net *net;
 	int err;
 
+	net = params->link_net ? : dev_net(dev);
 	xfrmi_netlink_parms(data, &p);
 	if (p.collect_md) {
 		struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id);
@@ -851,7 +852,7 @@ static int xfrmi_newlink(struct net *src_net, struct net_device *dev,
 	xi->net = net;
 	xi->dev = dev;
 
-	err = xfrmi_create(dev);
+	err = xfrmi_create(net, dev);
 	return err;
 }