Merge branch 'ifa_list-RCU'

Florian Westphal says:

====================
net: add rcu annotations for ifa_list

v3: fix typo in patch1 commit message
    All other patches are unchanged.
v2: remove ifa_list iteration in afs instead of conversion

Eric Dumazet reported following problem:

  It looks that unless RTNL is held, accessing ifa_list needs proper RCU
  protection.  indev->ifa_list can be changed under us by another cpu
  (which owns RTNL) [..]

  A proper rcu_dereference() with an happy sparse support would require
  adding __rcu attribute.

This patch series does that: add __rcu to the ifa_list pointers.
That makes sparse complain, so the series also adds the required
rcu_assign_pointer/dereference helpers where needed.

All patches except the last one are preparation work.
Two new macros are introduced for in_ifaddr walks.

Last patch adds the __rcu annotations and the assign_pointer/dereference
helper calls.

This patch is a bit large, but I found no better way -- other
approaches (annotate-first or add helpers-first) all result in
mid-series sparse warnings.

This series is submitted vs. net-next rather than net for several
reasons:

1. Its (mostly) compile-tested only
2. 3rd patch changes behaviour wrt. secondary addresses
   (see changelog)
3. The problem exists for a very long time (2004), so it doesn't
   seem to be urgent to fix this -- rcu use to free ifa_list
   predates the git era.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

34 files changed, 250 insertions, 229 deletions

diff --git a/drivers/infiniband/core/roce_gid_mgmt.c b/drivers/infiniband/core/roce_gid_mgmt.c
index 558de0b9895c..2860def84f4d 100644
--- a/drivers/infiniband/core/roce_gid_mgmt.c
+++ b/drivers/infiniband/core/roce_gid_mgmt.c
@@ -330,6 +330,7 @@ static void bond_delete_netdev_default_gids(struct ib_device *ib_dev,
 static void enum_netdev_ipv4_ips(struct ib_device *ib_dev,
 				 u8 port, struct net_device *ndev)
 {
+	const struct in_ifaddr *ifa;
 	struct in_device *in_dev;
 	struct sin_list {
 		struct list_head	list;
@@ -349,7 +350,7 @@ static void enum_netdev_ipv4_ips(struct ib_device *ib_dev,
 		return;
 	}
 
-	for_ifa(in_dev) {
+	in_dev_for_each_ifa_rcu(ifa, in_dev) {
 		struct sin_list *entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 
 		if (!entry)
@@ -359,7 +360,7 @@ static void enum_netdev_ipv4_ips(struct ib_device *ib_dev,
 		entry->ip.sin_addr.s_addr = ifa->ifa_address;
 		list_add_tail(&entry->list, &sin_list);
 	}
-	endfor_ifa(in_dev);
+
 	rcu_read_unlock();
 
 	list_for_each_entry_safe(sin_iter, sin_temp, &sin_list, list) {
diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index 0f3b1193d5f8..09fcfc9e052d 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -3230,17 +3230,22 @@ static int pick_local_ipaddrs(struct c4iw_dev *dev, struct iw_cm_id *cm_id)
 	int found = 0;
 	struct sockaddr_in *laddr = (struct sockaddr_in *)&cm_id->m_local_addr;
 	struct sockaddr_in *raddr = (struct sockaddr_in *)&cm_id->m_remote_addr;
+	const struct in_ifaddr *ifa;
 
 	ind = in_dev_get(dev->rdev.lldi.ports[0]);
 	if (!ind)
 		return -EADDRNOTAVAIL;
-	for_primary_ifa(ind) {
+	rcu_read_lock();
+	in_dev_for_each_ifa_rcu(ifa, ind) {
+		if (ifa->ifa_flags & IFA_F_SECONDARY)
+			continue;
 		laddr->sin_addr.s_addr = ifa->ifa_address;
 		raddr->sin_addr.s_addr = ifa->ifa_address;
 		found = 1;
 		break;
 	}
-	endfor_ifa(ind);
+	rcu_read_unlock();
+
 	in_dev_put(ind);
 	return found ? 0 : -EADDRNOTAVAIL;
 }
diff --git a/drivers/infiniband/hw/i40iw/i40iw_cm.c b/drivers/infiniband/hw/i40iw/i40iw_cm.c
index 8233f5a4e623..700a5d06b60c 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_cm.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_cm.c
@@ -1773,8 +1773,11 @@ static enum i40iw_status_code i40iw_add_mqh_4(
 		if ((((rdma_vlan_dev_vlan_id(dev) < I40IW_NO_VLAN) &&
 		      (rdma_vlan_dev_real_dev(dev) == iwdev->netdev)) ||
 		    (dev == iwdev->netdev)) && (dev->flags & IFF_UP)) {
+			const struct in_ifaddr *ifa;
+
 			idev = in_dev_get(dev);
-			for_ifa(idev) {
+
+			in_dev_for_each_ifa_rtnl(ifa, idev) {
 				i40iw_debug(&iwdev->sc_dev,
 					    I40IW_DEBUG_CM,
 					    "Allocating child CM Listener forIP=%pI4, vlan_id=%d, MAC=%pM\n",
@@ -1819,7 +1822,7 @@ static enum i40iw_status_code i40iw_add_mqh_4(
 					cm_parent_listen_node->cm_core->stats_listen_nodes_created--;
 				}
 			}
-			endfor_ifa(idev);
+
 			in_dev_put(idev);
 		}
 	}
diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c b/drivers/infiniband/hw/i40iw/i40iw_main.c
index 10932baee279..d44cf33df81a 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_main.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_main.c
@@ -1222,8 +1222,10 @@ static void i40iw_add_ipv4_addr(struct i40iw_device *iwdev)
 		if ((((rdma_vlan_dev_vlan_id(dev) < 0xFFFF) &&
 		      (rdma_vlan_dev_real_dev(dev) == iwdev->netdev)) ||
 		    (dev == iwdev->netdev)) && (dev->flags & IFF_UP)) {
+			const struct in_ifaddr *ifa;
+
 			idev = in_dev_get(dev);
-			for_ifa(idev) {
+			in_dev_for_each_ifa_rtnl(ifa, idev) {
 				i40iw_debug(&iwdev->sc_dev, I40IW_DEBUG_CM,
 					    "IP=%pI4, vlan_id=%d, MAC=%pM\n", &ifa->ifa_address,
 					     rdma_vlan_dev_vlan_id(dev), dev->dev_addr);
@@ -1235,7 +1237,7 @@ static void i40iw_add_ipv4_addr(struct i40iw_device *iwdev)
 						       true,
 						       I40IW_ARP_ADD);
 			}
-			endfor_ifa(idev);
+
 			in_dev_put(idev);
 		}
 	}
diff --git a/drivers/infiniband/hw/i40iw/i40iw_utils.c b/drivers/infiniband/hw/i40iw/i40iw_utils.c
index 337410f40860..016524683e17 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_utils.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_utils.c
@@ -174,10 +174,14 @@ int i40iw_inetaddr_event(struct notifier_block *notifier,
 		rcu_read_lock();
 		in = __in_dev_get_rcu(upper_dev);
 
-		if (!in->ifa_list)
-			local_ipaddr = 0;
-		else
-			local_ipaddr = ntohl(in->ifa_list->ifa_address);
+		local_ipaddr = 0;
+		if (in) {
+			struct in_ifaddr *ifa;
+
+			ifa = rcu_dereference(in->ifa_list);
+			if (ifa)
+				local_ipaddr = ntohl(ifa->ifa_address);
+		}
 
 		rcu_read_unlock();
 	} else {
diff --git a/drivers/infiniband/hw/nes/nes.c b/drivers/infiniband/hw/nes/nes.c
index e00add6d78ec..29b324726ea6 100644
--- a/drivers/infiniband/hw/nes/nes.c
+++ b/drivers/infiniband/hw/nes/nes.c
@@ -183,7 +183,13 @@ static int nes_inetaddr_event(struct notifier_block *notifier,
 
 						rcu_read_lock();
 						in = __in_dev_get_rcu(upper_dev);
-						nesvnic->local_ipaddr = in->ifa_list->ifa_address;
+						if (in) {
+							struct in_ifaddr *ifa;
+
+							ifa = rcu_dereference(in->ifa_list);
+							if (ifa)
+								nesvnic->local_ipaddr = ifa->ifa_address;
+						}
 						rcu_read_unlock();
 					} else {
 						nesvnic->local_ipaddr = ifa->ifa_address;
diff --git a/drivers/infiniband/hw/usnic/usnic_ib_main.c b/drivers/infiniband/hw/usnic/usnic_ib_main.c
index d88d9f8a7f9a..34c1f9d6c915 100644
--- a/drivers/infiniband/hw/usnic/usnic_ib_main.c
+++ b/drivers/infiniband/hw/usnic/usnic_ib_main.c
@@ -427,11 +427,16 @@ static void *usnic_ib_device_add(struct pci_dev *dev)
 	if (netif_carrier_ok(us_ibdev->netdev))
 		usnic_fwd_carrier_up(us_ibdev->ufdev);
 
-	ind = in_dev_get(netdev);
-	if (ind->ifa_list)
-		usnic_fwd_add_ipaddr(us_ibdev->ufdev,
-				     ind->ifa_list->ifa_address);
-	in_dev_put(ind);
+	rcu_read_lock();
+	ind = __in_dev_get_rcu(netdev);
+	if (ind) {
+		const struct in_ifaddr *ifa;
+
+		ifa = rcu_dereference(ind->ifa_list);
+		if (ifa)
+			usnic_fwd_add_ipaddr(us_ibdev->ufdev, ifa->ifa_address);
+	}
+	rcu_read_unlock();
 
 	usnic_mac_ip_to_gid(us_ibdev->netdev->perm_addr,
 				us_ibdev->ufdev->inaddr, &gid.raw[0]);
diff --git a/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c b/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c
index 84cb62434556..58e2eaf77014 100644
--- a/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c
+++ b/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c
@@ -3248,6 +3248,7 @@ netxen_config_indev_addr(struct netxen_adapter *adapter,
 		struct net_device *dev, unsigned long event)
 {
 	struct in_device *indev;
+	struct in_ifaddr *ifa;
 
 	if (!netxen_destip_supported(adapter))
 		return;
@@ -3256,7 +3257,8 @@ netxen_config_indev_addr(struct netxen_adapter *adapter,
 	if (!indev)
 		return;
 
-	for_ifa(indev) {
+	rcu_read_lock();
+	in_dev_for_each_ifa_rcu(ifa, indev) {
 		switch (event) {
 		case NETDEV_UP:
 			netxen_list_config_ip(adapter, ifa, NX_IP_UP);
@@ -3267,8 +3269,8 @@ netxen_config_indev_addr(struct netxen_adapter *adapter,
 		default:
 			break;
 		}
-	} endfor_ifa(indev);
-
+	}
+	rcu_read_unlock();
 	in_dev_put(indev);
 }
 
diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
index 7a873002e626..c07438db30ba 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
@@ -4119,13 +4119,14 @@ static void
 qlcnic_config_indev_addr(struct qlcnic_adapter *adapter,
 			struct net_device *dev, unsigned long event)
 {
+	const struct in_ifaddr *ifa;
 	struct in_device *indev;
 
 	indev = in_dev_get(dev);
 	if (!indev)
 		return;
 
-	for_ifa(indev) {
+	in_dev_for_each_ifa_rtnl(ifa, indev) {
 		switch (event) {
 		case NETDEV_UP:
 			qlcnic_config_ipaddr(adapter,
@@ -4138,7 +4139,7 @@ qlcnic_config_indev_addr(struct qlcnic_adapter *adapter,
 		default:
 			break;
 		}
-	} endfor_ifa(indev);
+	}
 
 	in_dev_put(indev);
 }
diff --git a/drivers/net/ethernet/via/via-velocity.h b/drivers/net/ethernet/via/via-velocity.h
index c0ecc6c7b5e0..cdfe7809e3c1 100644
--- a/drivers/net/ethernet/via/via-velocity.h
+++ b/drivers/net/ethernet/via/via-velocity.h
@@ -1509,7 +1509,7 @@ static inline int velocity_get_ip(struct velocity_info *vptr)
 	rcu_read_lock();
 	in_dev = __in_dev_get_rcu(vptr->netdev);
 	if (in_dev != NULL) {
-		ifa = (struct in_ifaddr *) in_dev->ifa_list;
+		ifa = rcu_dereference(in_dev->ifa_list);
 		if (ifa != NULL) {
 			memcpy(vptr->ip_addr, &ifa->ifa_address, 4);
 			res = 0;
diff --git a/drivers/net/plip/plip.c b/drivers/net/plip/plip.c
index feb92ecd1880..3e3ac2e496a1 100644
--- a/drivers/net/plip/plip.c
+++ b/drivers/net/plip/plip.c
@@ -1012,7 +1012,7 @@ plip_rewrite_address(const struct net_device *dev, struct ethhdr *eth)
 	in_dev = __in_dev_get_rcu(dev);
 	if (in_dev) {
 		/* Any address will do - we take the first */
-		const struct in_ifaddr *ifa = in_dev->ifa_list;
+		const struct in_ifaddr *ifa = rcu_dereference(in_dev->ifa_list);
 		if (ifa) {
 			memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
 			memset(eth->h_dest, 0xfc, 2);
@@ -1107,7 +1107,7 @@ plip_open(struct net_device *dev)
 		/* Any address will do - we take the first. We already
 		   have the first two bytes filled with 0xfc, from
 		   plip_init_dev(). */
-		struct in_ifaddr *ifa=in_dev->ifa_list;
+		const struct in_ifaddr *ifa = rcu_dereference(in_dev->ifa_list);
 		if (ifa != NULL) {
 			memcpy(dev->dev_addr+2, &ifa->ifa_local, 4);
 		}
diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index 89984fcab01e..1b2a18ea855c 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -3651,13 +3651,19 @@ vmxnet3_suspend(struct device *device)
 	}
 
 	if (adapter->wol & WAKE_ARP) {
-		in_dev = in_dev_get(netdev);
-		if (!in_dev)
+		rcu_read_lock();
+
+		in_dev = __in_dev_get_rcu(netdev);
+		if (!in_dev) {
+			rcu_read_unlock();
 			goto skip_arp;
+		}
 
-		ifa = (struct in_ifaddr *)in_dev->ifa_list;
-		if (!ifa)
+		ifa = rcu_dereference(in_dev->ifa_list);
+		if (!ifa) {
+			rcu_read_unlock();
 			goto skip_arp;
+		}
 
 		pmConf->filters[i].patternSize = ETH_HLEN + /* Ethernet header*/
 			sizeof(struct arphdr) +		/* ARP header */
@@ -3677,7 +3683,9 @@ vmxnet3_suspend(struct device *device)
 
 		/* The Unicast IPv4 address in 'tip' field. */
 		arpreq += 2 * ETH_ALEN + sizeof(u32);
-		*(u32 *)arpreq = ifa->ifa_address;
+		*(__be32 *)arpreq = ifa->ifa_address;
+
+		rcu_read_unlock();
 
 		/* The mask for the relevant bits. */
 		pmConf->filters[i].mask[0] = 0x00;
@@ -3686,7 +3694,6 @@ vmxnet3_suspend(struct device *device)
 		pmConf->filters[i].mask[3] = 0x00;
 		pmConf->filters[i].mask[4] = 0xC0; /* IPv4 TIP */
 		pmConf->filters[i].mask[5] = 0x03; /* IPv4 TIP */
-		in_dev_put(in_dev);
 
 		pmConf->wakeUpEvents |= VMXNET3_PM_WAKEUP_FILTER;
 		i++;
diff --git a/drivers/net/wan/hdlc_cisco.c b/drivers/net/wan/hdlc_cisco.c
index 320039d329c7..4976ca3f30c7 100644
--- a/drivers/net/wan/hdlc_cisco.c
+++ b/drivers/net/wan/hdlc_cisco.c
@@ -196,16 +196,15 @@ static int cisco_rx(struct sk_buff *skb)
 			mask = ~cpu_to_be32(0); /* is the mask correct? */
 
 			if (in_dev != NULL) {
-				struct in_ifaddr **ifap = &in_dev->ifa_list;
+				const struct in_ifaddr *ifa;
 
-				while (*ifap != NULL) {
+				in_dev_for_each_ifa_rcu(ifa, in_dev) {
 					if (strcmp(dev->name,
-						   (*ifap)->ifa_label) == 0) {
-						addr = (*ifap)->ifa_local;
-						mask = (*ifap)->ifa_mask;
+						   ifa->ifa_label) == 0) {
+						addr = ifa->ifa_local;
+						mask = ifa->ifa_mask;
 						break;
 					}
-					ifap = &(*ifap)->ifa_next;
 				}
 
 				cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
diff --git a/drivers/net/wireless/ath/ath6kl/cfg80211.c b/drivers/net/wireless/ath/ath6kl/cfg80211.c
index 5477a014e1fb..37cf602d8adf 100644
--- a/drivers/net/wireless/ath/ath6kl/cfg80211.c
+++ b/drivers/net/wireless/ath/ath6kl/cfg80211.c
@@ -2194,13 +2194,13 @@ static int ath6kl_wow_suspend_vif(struct ath6kl_vif *vif,
 	if (!in_dev)
 		return 0;
 
-	ifa = in_dev->ifa_list;
+	ifa = rtnl_dereference(in_dev->ifa_list);
 	memset(&ips, 0, sizeof(ips));
 
 	/* Configure IP addr only if IP address count < MAX_IP_ADDRS */
 	while (index < MAX_IP_ADDRS && ifa) {
 		ips[index] = ifa->ifa_local;
-		ifa = ifa->ifa_next;
+		ifa = rtnl_dereference(ifa->ifa_next);
 		index++;
 	}
 
diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
index e11a4bb67172..5a7cdb981789 100644
--- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c
+++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
@@ -3268,7 +3268,7 @@ static void mwifiex_set_auto_arp_mef_entry(struct mwifiex_private *priv,
 			in_dev = __in_dev_get_rtnl(adapter->priv[i]->netdev);
 			if (!in_dev)
 				continue;
-			ifa = in_dev->ifa_list;
+			ifa = rtnl_dereference(in_dev->ifa_list);
 			if (!ifa || !ifa->ifa_local)
 				continue;
 			ips[i] = ifa->ifa_local;
diff --git a/drivers/staging/isdn/hysdn/hysdn_net.c b/drivers/staging/isdn/hysdn/hysdn_net.c
index 8e9c34f33d86..bea37ae30ebb 100644
--- a/drivers/staging/isdn/hysdn/hysdn_net.c
+++ b/drivers/staging/isdn/hysdn/hysdn_net.c
@@ -70,9 +70,13 @@ net_open(struct net_device *dev)
 		for (i = 0; i < ETH_ALEN; i++)
 			dev->dev_addr[i] = 0xfc;
 		if ((in_dev = dev->ip_ptr) != NULL) {
-			struct in_ifaddr *ifa = in_dev->ifa_list;
+			const struct in_ifaddr *ifa;
+
+			rcu_read_lock();
+			ifa = rcu_dereference(in_dev->ifa_list);
 			if (ifa != NULL)
 				memcpy(dev->dev_addr + (ETH_ALEN - sizeof(ifa->ifa_local)), &ifa->ifa_local, sizeof(ifa->ifa_local));
+			rcu_read_unlock();
 		}
 	} else
 		memcpy(dev->dev_addr, card->mac_addr, ETH_ALEN);
diff --git a/fs/afs/Makefile b/fs/afs/Makefile
index cbf31f6cd177..10359bea7070 100644
--- a/fs/afs/Makefile
+++ b/fs/afs/Makefile
@@ -29,7 +29,6 @@ kafs-y := \
 	server.o \
 	server_list.o \
 	super.o \
-	netdevices.o \
 	vlclient.o \
 	vl_list.o \
 	vl_probe.o \
diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 01437cfe5432..a61d2058c468 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -584,9 +584,8 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
  */
 static void SRXAFSCB_TellMeAboutYourself(struct work_struct *work)
 {
-	struct afs_interface *ifs;
 	struct afs_call *call = container_of(work, struct afs_call, work);
-	int loop, nifs;
+	int loop;
 
 	struct {
 		struct /* InterfaceAddr */ {
@@ -604,19 +603,7 @@ static void SRXAFSCB_TellMeAboutYourself(struct work_struct *work)
 
 	_enter("");
 
-	nifs = 0;
-	ifs = kcalloc(32, sizeof(*ifs), GFP_KERNEL);
-	if (ifs) {
-		nifs = afs_get_ipv4_interfaces(call->net, ifs, 32, false);
-		if (nifs < 0) {
-			kfree(ifs);
-			ifs = NULL;
-			nifs = 0;
-		}
-	}
-
 	memset(&reply, 0, sizeof(reply));
-	reply.ia.nifs = htonl(nifs);
 
 	reply.ia.uuid[0] = call->net->uuid.time_low;
 	reply.ia.uuid[1] = htonl(ntohs(call->net->uuid.time_mid));
@@ -626,15 +613,6 @@ static void SRXAFSCB_TellMeAboutYourself(struct work_struct *work)
 	for (loop = 0; loop < 6; loop++)
 		reply.ia.uuid[loop + 5] = htonl((s8) call->net->uuid.node[loop]);
 
-	if (ifs) {
-		for (loop = 0; loop < nifs; loop++) {
-			reply.ia.ifaddr[loop] = ifs[loop].address.s_addr;
-			reply.ia.netmask[loop] = ifs[loop].netmask.s_addr;
-			reply.ia.mtu[loop] = htonl(ifs[loop].mtu);
-		}
-		kfree(ifs);
-	}
-
 	reply.cap.capcount = htonl(1);
 	reply.cap.caps[0] = htonl(AFS_CAP_ERROR_TRANSLATION);
 	afs_send_simple_reply(call, &reply, sizeof(reply));
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 2073c1a3ab4b..a22fa3b77b3c 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -725,15 +725,6 @@ struct afs_permits {
 };
 
 /*
- * record of one of a system's set of network interfaces
- */
-struct afs_interface {
-	struct in_addr	address;	/* IPv4 address bound to interface */
-	struct in_addr	netmask;	/* netmask applied to address */
-	unsigned	mtu;		/* MTU of interface */
-};
-
-/*
  * Error prioritisation and accumulation.
  */
 struct afs_error {
@@ -1096,12 +1087,6 @@ extern struct vfsmount *afs_d_automount(struct path *);
 extern void afs_mntpt_kill_timer(void);
 
 /*
- * netdevices.c
- */
-extern int afs_get_ipv4_interfaces(struct afs_net *, struct afs_interface *,
-				   size_t, bool);
-
-/*
  * proc.c
  */
 #ifdef CONFIG_PROC_FS
diff --git a/fs/afs/netdevices.c b/fs/afs/netdevices.c
deleted file mode 100644
index 2a009d1939d7..000000000000
--- a/fs/afs/netdevices.c
+++ /dev/null
@@ -1,48 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/* AFS network device helpers
- *
- * Copyright (c) 2007 Patrick McHardy <kaber@trash.net>
- */
-
-#include <linux/string.h>
-#include <linux/rtnetlink.h>
-#include <linux/inetdevice.h>
-#include <linux/netdevice.h>
-#include <linux/if_arp.h>
-#include <net/net_namespace.h>
-#include "internal.h"
-
-/*
- * get a list of this system's interface IPv4 addresses, netmasks and MTUs
- * - maxbufs must be at least 1
- * - returns the number of interface records in the buffer
- */
-int afs_get_ipv4_interfaces(struct afs_net *net, struct afs_interface *bufs,
-			    size_t maxbufs, bool wantloopback)
-{
-	struct net_device *dev;
-	struct in_device *idev;
-	int n = 0;
-
-	ASSERT(maxbufs > 0);
-
-	rtnl_lock();
-	for_each_netdev(net->net, dev) {
-		if (dev->type == ARPHRD_LOOPBACK && !wantloopback)
-			continue;
-		idev = __in_dev_get_rtnl(dev);
-		if (!idev)
-			continue;
-		for_primary_ifa(idev) {
-			bufs[n].address.s_addr = ifa->ifa_address;
-			bufs[n].netmask.s_addr = ifa->ifa_mask;
-			bufs[n].mtu = dev->mtu;
-			n++;
-			if (n >= maxbufs)
-				goto out;
-		} endfor_ifa(idev);
-	}
-out:
-	rtnl_unlock();
-	return n;
-}
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index 367dc2a0f84a..3515ca64e638 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -26,7 +26,7 @@ struct in_device {
 	struct net_device	*dev;
 	refcount_t		refcnt;
 	int			dead;
-	struct in_ifaddr	*ifa_list;	/* IP ifaddr chain		*/
+	struct in_ifaddr	__rcu *ifa_list;/* IP ifaddr chain		*/
 
 	struct ip_mc_list __rcu	*mc_list;	/* IP multicast filter chain    */
 	struct ip_mc_list __rcu	* __rcu *mc_hash;
@@ -136,7 +136,7 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev)
 
 struct in_ifaddr {
 	struct hlist_node	hash;
-	struct in_ifaddr	*ifa_next;
+	struct in_ifaddr	__rcu *ifa_next;
 	struct in_device	*ifa_dev;
 	struct rcu_head		rcu_head;
 	__be32			ifa_local;
@@ -186,7 +186,7 @@ __be32 inet_confirm_addr(struct net *net, struct in_device *in_dev, __be32 dst,
 struct in_ifaddr *inet_ifa_byprefix(struct in_device *in_dev, __be32 prefix,
 				    __be32 mask);
 struct in_ifaddr *inet_lookup_ifaddr_rcu(struct net *net, __be32 addr);
-static __inline__ bool inet_ifa_match(__be32 addr, struct in_ifaddr *ifa)
+static inline bool inet_ifa_match(__be32 addr, const struct in_ifaddr *ifa)
 {
 	return !((addr^ifa->ifa_address)&ifa->ifa_mask);
 }
@@ -206,14 +206,13 @@ static __inline__ bool bad_mask(__be32 mask, __be32 addr)
 	return false;
 }
 
-#define for_primary_ifa(in_dev)	{ struct in_ifaddr *ifa; \
-  for (ifa = (in_dev)->ifa_list; ifa && !(ifa->ifa_flags&IFA_F_SECONDARY); ifa = ifa->ifa_next)
+#define in_dev_for_each_ifa_rtnl(ifa, in_dev)			\
+	for (ifa = rtnl_dereference((in_dev)->ifa_list); ifa;	\
+	     ifa = rtnl_dereference(ifa->ifa_next))
 
-#define for_ifa(in_dev)	{ struct in_ifaddr *ifa; \
-  for (ifa = (in_dev)->ifa_list; ifa; ifa = ifa->ifa_next)
-
-
-#define endfor_ifa(in_dev) }
+#define in_dev_for_each_ifa_rcu(ifa, in_dev)			\
+	for (ifa = rcu_dereference((in_dev)->ifa_list); ifa;	\
+	     ifa = rcu_dereference(ifa->ifa_next))
 
 static inline struct in_device *__in_dev_get_rcu(const struct net_device *dev)
 {
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index dd8b1a460d64..2cf27da1baeb 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -696,16 +696,22 @@ int netpoll_setup(struct netpoll *np)
 
 	if (!np->local_ip.ip) {
 		if (!np->ipv6) {
+			const struct in_ifaddr *ifa;
+
 			in_dev = __in_dev_get_rtnl(ndev);
+			if (!in_dev)
+				goto put_noaddr;
 
-			if (!in_dev || !in_dev->ifa_list) {
+			ifa = rtnl_dereference(in_dev->ifa_list);
+			if (!ifa) {
+put_noaddr:
 				np_err(np, "no IP address for %s, aborting\n",
 				       np->dev_name);
 				err = -EDESTADDRREQ;
 				goto put;
 			}
 
-			np->local_ip.ip = in_dev->ifa_list->ifa_local;
+			np->local_ip.ip = ifa->ifa_local;
 			np_info(np, "local IP %pI4\n", &np->local_ip.ip);
 		} else {
 #if IS_ENABLED(CONFIG_IPV6)
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 319ad5490fb3..4cd120dc30ad 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2125,9 +2125,11 @@ static void pktgen_setup_inject(struct pktgen_dev *pkt_dev)
 			rcu_read_lock();
 			in_dev = __in_dev_get_rcu(pkt_dev->odev);
 			if (in_dev) {
-				if (in_dev->ifa_list) {
-					pkt_dev->saddr_min =
-					    in_dev->ifa_list->ifa_address;
+				const struct in_ifaddr *ifa;
+
+				ifa = rcu_dereference(in_dev->ifa_list);
+				if (ifa) {
+					pkt_dev->saddr_min = ifa->ifa_address;
 					pkt_dev->saddr_max = pkt_dev->saddr_min;
 				}
 			}
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 701c5d113a34..ebaea05b4033 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -194,7 +194,8 @@ static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);
 
 static BLOCKING_NOTIFIER_HEAD(inetaddr_chain);
 static BLOCKING_NOTIFIER_HEAD(inetaddr_validator_chain);
-static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
+static void inet_del_ifa(struct in_device *in_dev,
+			 struct in_ifaddr __rcu **ifap,
 			 int destroy);
 #ifdef CONFIG_SYSCTL
 static int devinet_sysctl_register(struct in_device *idev);
@@ -300,8 +301,8 @@ static void in_dev_rcu_put(struct rcu_head *head)
 
 static void inetdev_destroy(struct in_device *in_dev)
 {
-	struct in_ifaddr *ifa;
 	struct net_device *dev;
+	struct in_ifaddr *ifa;
 
 	ASSERT_RTNL();
 
@@ -311,7 +312,7 @@ static void inetdev_destroy(struct in_device *in_dev)
 
 	ip_mc_destroy_dev(in_dev);
 
-	while ((ifa = in_dev->ifa_list) != NULL) {
+	while ((ifa = rtnl_dereference(in_dev->ifa_list)) != NULL) {
 		inet_del_ifa(in_dev, &in_dev->ifa_list, 0);
 		inet_free_ifa(ifa);
 	}
@@ -327,30 +328,35 @@ static void inetdev_destroy(struct in_device *in_dev)
 
 int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b)
 {
+	const struct in_ifaddr *ifa;
+
 	rcu_read_lock();
-	for_primary_ifa(in_dev) {
+	in_dev_for_each_ifa_rcu(ifa, in_dev) {
 		if (inet_ifa_match(a, ifa)) {
 			if (!b || inet_ifa_match(b, ifa)) {
 				rcu_read_unlock();
 				return 1;
 			}
 		}
-	} endfor_ifa(in_dev);
+	}
 	rcu_read_unlock();
 	return 0;
 }
 
-static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
-			 int destroy, struct nlmsghdr *nlh, u32 portid)
+static void __inet_del_ifa(struct in_device *in_dev,
+			   struct in_ifaddr __rcu **ifap,
+			   int destroy, struct nlmsghdr *nlh, u32 portid)
 {
 	struct in_ifaddr *promote = NULL;
-	struct in_ifaddr *ifa, *ifa1 = *ifap;
-	struct in_ifaddr *last_prim = in_dev->ifa_list;
+	struct in_ifaddr *ifa, *ifa1;
+	struct in_ifaddr *last_prim;
 	struct in_ifaddr *prev_prom = NULL;
 	int do_promote = IN_DEV_PROMOTE_SECONDARIES(in_dev);
 
 	ASSERT_RTNL();
 
+	ifa1 = rtnl_dereference(*ifap);
+	last_prim = rtnl_dereference(in_dev->ifa_list);
 	if (in_dev->dead)
 		goto no_promotions;
 
@@ -359,9 +365,9 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
 	 **/
 
 	if (!(ifa1->ifa_flags & IFA_F_SECONDARY)) {
-		struct in_ifaddr **ifap1 = &ifa1->ifa_next;
+		struct in_ifaddr __rcu **ifap1 = &ifa1->ifa_next;
 
-		while ((ifa = *ifap1) != NULL) {
+		while ((ifa = rtnl_dereference(*ifap1)) != NULL) {
 			if (!(ifa-&g