net: Fix inconsistent teardown and release of private netdev state.
Network devices can allocate reasources and private memory using
netdev_ops->ndo_init(). However, the release of these resources
can occur in one of two different places.
Either netdev_ops->ndo_uninit() or netdev->destructor().
The decision of which operation frees the resources depends upon
whether it is necessary for all netdev refs to be released before it
is safe to perform the freeing.
netdev_ops->ndo_uninit() presumably can occur right after the
NETDEV_UNREGISTER notifier completes and the unicast and multicast
address lists are flushed.
netdev->destructor(), on the other hand, does not run until the
netdev references all go away.
Further complicating the situation is that netdev->destructor()
almost universally does also a free_netdev().
This creates a problem for the logic in register_netdevice().
Because all callers of register_netdevice() manage the freeing
of the netdev, and invoke free_netdev(dev) if register_netdevice()
fails.
If netdev_ops->ndo_init() succeeds, but something else fails inside
of register_netdevice(), it does call ndo_ops->ndo_uninit(). But
it is not able to invoke netdev->destructor().
This is because netdev->destructor() will do a free_netdev() and
then the caller of register_netdevice() will do the same.
However, this means that the resources that would normally be released
by netdev->destructor() will not be.
Over the years drivers have added local hacks to deal with this, by
invoking their destructor parts by hand when register_netdevice()
fails.
Many drivers do not try to deal with this, and instead we have leaks.
Let's close this hole by formalizing the distinction between what
private things need to be freed up by netdev->destructor() and whether
the driver needs unregister_netdevice() to perform the free_netdev().
netdev->priv_destructor() performs all actions to free up the private
resources that used to be freed by netdev->destructor(), except for
free_netdev().
netdev->needs_free_netdev is a boolean that indicates whether
free_netdev() should be done at the end of unregister_netdevice().
Now, register_netdevice() can sanely release all resources after
ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit()
and netdev->priv_destructor().
And at the end of unregister_netdevice(), we invoke
netdev->priv_destructor() and optionally call free_netdev().
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 953b672..abc5f40 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -813,7 +813,6 @@
free_percpu(vlan->vlan_pcpu_stats);
vlan->vlan_pcpu_stats = NULL;
- free_netdev(dev);
}
void vlan_setup(struct net_device *dev)
@@ -826,7 +825,8 @@
netif_keep_dst(dev);
dev->netdev_ops = &vlan_netdev_ops;
- dev->destructor = vlan_dev_free;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = vlan_dev_free;
dev->ethtool_ops = &vlan_ethtool_ops;
dev->min_mtu = 0;
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index b25789a..10f7edf 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -1034,8 +1034,6 @@
* netdev and its private data (bat_priv)
*/
rcu_barrier();
-
- free_netdev(dev);
}
/**
@@ -1047,7 +1045,8 @@
ether_setup(dev);
dev->netdev_ops = &batadv_netdev_ops;
- dev->destructor = batadv_softif_free;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = batadv_softif_free;
dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_NETNS_LOCAL;
dev->priv_flags |= IFF_NO_QUEUE;
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 6089599..ab3b654 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -598,7 +598,7 @@
dev->netdev_ops = &netdev_ops;
dev->header_ops = &header_ops;
- dev->destructor = free_netdev;
+ dev->needs_free_netdev = true;
}
static struct device_type bt_type = {
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 430b53e..f0f3447 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -379,7 +379,7 @@
ether_setup(dev);
dev->netdev_ops = &br_netdev_ops;
- dev->destructor = free_netdev;
+ dev->needs_free_netdev = true;
dev->ethtool_ops = &br_ethtool_ops;
SET_NETDEV_DEVTYPE(dev, &br_type);
dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
diff --git a/net/caif/chnl_net.c b/net/caif/chnl_net.c
index 1816fc9..fe3c53e 100644
--- a/net/caif/chnl_net.c
+++ b/net/caif/chnl_net.c
@@ -392,14 +392,14 @@
{
struct chnl_net *priv = netdev_priv(dev);
caif_free_client(&priv->chnl);
- free_netdev(dev);
}
static void ipcaif_net_setup(struct net_device *dev)
{
struct chnl_net *priv;
dev->netdev_ops = &netdev_ops;
- dev->destructor = chnl_net_destructor;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = chnl_net_destructor;
dev->flags |= IFF_NOARP;
dev->flags |= IFF_POINTOPOINT;
dev->mtu = GPRS_PDP_MTU;
diff --git a/net/core/dev.c b/net/core/dev.c
index 84e1e86..4c15466 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7502,6 +7502,8 @@
err_uninit:
if (dev->netdev_ops->ndo_uninit)
dev->netdev_ops->ndo_uninit(dev);
+ if (dev->priv_destructor)
+ dev->priv_destructor(dev);
goto out;
}
EXPORT_SYMBOL(register_netdevice);
@@ -7709,8 +7711,10 @@
WARN_ON(rcu_access_pointer(dev->ip6_ptr));
WARN_ON(dev->dn_ptr);
- if (dev->destructor)
- dev->destructor(dev);
+ if (dev->priv_destructor)
+ dev->priv_destructor(dev);
+ if (dev->needs_free_netdev)
+ free_netdev(dev);
/* Report a network device has been unregistered */
rtnl_lock();
diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c
index c73160f..0a0a392 100644
--- a/net/hsr/hsr_device.c
+++ b/net/hsr/hsr_device.c
@@ -378,7 +378,6 @@
del_timer_sync(&hsr->announce_timer);
synchronize_rcu();
- free_netdev(hsr_dev);
}
static const struct net_device_ops hsr_device_ops = {
@@ -404,7 +403,8 @@
SET_NETDEV_DEVTYPE(dev, &hsr_type);
dev->priv_flags |= IFF_NO_QUEUE;
- dev->destructor = hsr_dev_destroy;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = hsr_dev_destroy;
dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c
index d7efbf0..0a866f33 100644
--- a/net/ieee802154/6lowpan/core.c
+++ b/net/ieee802154/6lowpan/core.c
@@ -107,7 +107,7 @@
ldev->netdev_ops = &lowpan_netdev_ops;
ldev->header_ops = &lowpan_header_ops;
- ldev->destructor = free_netdev;
+ ldev->needs_free_netdev = true;
ldev->features |= NETIF_F_NETNS_LOCAL;
}
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index b878ecb..b436d07 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -967,7 +967,6 @@
gro_cells_destroy(&tunnel->gro_cells);
dst_cache_destroy(&tunnel->dst_cache);
free_percpu(dev->tstats);
- free_netdev(dev);
}
void ip_tunnel_dellink(struct net_device *dev, struct list_head *head)
@@ -1155,7 +1154,8 @@
struct iphdr *iph = &tunnel->parms.iph;
int err;
- dev->destructor = ip_tunnel_dev_free;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = ip_tunnel_dev_free;
dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
if (!dev->tstats)
return -ENOMEM;
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 551de4d..b4f9622 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -501,7 +501,7 @@
dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 8;
dev->flags = IFF_NOARP;
dev->netdev_ops = ®_vif_netdev_ops;
- dev->destructor = free_netdev;
+ dev->needs_free_netdev = true;
dev->features |= NETIF_F_NETNS_LOCAL;
}
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 0c5b4caa..64eea396 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -991,13 +991,13 @@
dst_cache_destroy(&t->dst_cache);
free_percpu(dev->tstats);
- free_netdev(dev);
}
static void ip6gre_tunnel_setup(struct net_device *dev)
{
dev->netdev_ops = &ip6gre_netdev_ops;
- dev->destructor = ip6gre_dev_free;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = ip6gre_dev_free;
dev->type = ARPHRD_IP6GRE;
@@ -1148,7 +1148,7 @@
return 0;
err_reg_dev:
- ip6gre_dev_free(ign->fb_tunnel_dev);
+ free_netdev(ign->fb_tunnel_dev);
err_alloc_dev:
return err;
}
@@ -1300,7 +1300,8 @@
ether_setup(dev);
dev->netdev_ops = &ip6gre_tap_netdev_ops;
- dev->destructor = ip6gre_dev_free;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = ip6gre_dev_free;
dev->features |= NETIF_F_NETNS_LOCAL;
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 9b37f97..c358197 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -254,7 +254,6 @@
gro_cells_destroy(&t->gro_cells);
dst_cache_destroy(&t->dst_cache);
free_percpu(dev->tstats);
- free_netdev(dev);
}
static int ip6_tnl_create2(struct net_device *dev)
@@ -322,7 +321,7 @@
return t;
failed_free:
- ip6_dev_free(dev);
+ free_netdev(dev);
failed:
return ERR_PTR(err);
}
@@ -1777,7 +1776,8 @@
static void ip6_tnl_dev_setup(struct net_device *dev)
{
dev->netdev_ops = &ip6_tnl_netdev_ops;
- dev->destructor = ip6_dev_free;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = ip6_dev_free;
dev->type = ARPHRD_TUNNEL6;
dev->flags |= IFF_NOARP;
@@ -2224,7 +2224,7 @@
return 0;
err_register:
- ip6_dev_free(ip6n->fb_tnl_dev);
+ free_netdev(ip6n->fb_tnl_dev);
err_alloc_dev:
return err;
}
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index d67ef564..837ea1e 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -180,7 +180,6 @@
static void vti6_dev_free(struct net_device *dev)
{
free_percpu(dev->tstats);
- free_netdev(dev);
}
static int vti6_tnl_create2(struct net_device *dev)
@@ -235,7 +234,7 @@
return t;
failed_free:
- vti6_dev_free(dev);
+ free_netdev(dev);
failed:
return NULL;
}
@@ -842,7 +841,8 @@
static void vti6_dev_setup(struct net_device *dev)
{
dev->netdev_ops = &vti6_netdev_ops;
- dev->destructor = vti6_dev_free;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = vti6_dev_free;
dev->type = ARPHRD_TUNNEL6;
dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr);
@@ -1100,7 +1100,7 @@
return 0;
err_register:
- vti6_dev_free(ip6n->fb_tnl_dev);
+ free_netdev(ip6n->fb_tnl_dev);
err_alloc_dev:
return err;
}
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 374997d..2ecb39b 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -733,7 +733,7 @@
dev->mtu = 1500 - sizeof(struct ipv6hdr) - 8;
dev->flags = IFF_NOARP;
dev->netdev_ops = ®_vif_netdev_ops;
- dev->destructor = free_netdev;
+ dev->needs_free_netdev = true;
dev->features |= NETIF_F_NETNS_LOCAL;
}
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 61e5902..2378503 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -265,7 +265,7 @@
return nt;
failed_free:
- ipip6_dev_free(dev);
+ free_netdev(dev);
failed:
return NULL;
}
@@ -1336,7 +1336,6 @@
dst_cache_destroy(&tunnel->dst_cache);
free_percpu(dev->tstats);
- free_netdev(dev);
}
#define SIT_FEATURES (NETIF_F_SG | \
@@ -1351,7 +1350,8 @@
int t_hlen = tunnel->hlen + sizeof(struct iphdr);
dev->netdev_ops = &ipip6_netdev_ops;
- dev->destructor = ipip6_dev_free;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = ipip6_dev_free;
dev->type = ARPHRD_SIT;
dev->hard_header_len = LL_MAX_HEADER + t_hlen;
diff --git a/net/irda/irlan/irlan_eth.c b/net/irda/irlan/irlan_eth.c
index 74d09f9..3be8528 100644
--- a/net/irda/irlan/irlan_eth.c
+++ b/net/irda/irlan/irlan_eth.c
@@ -65,7 +65,7 @@
ether_setup(dev);
dev->netdev_ops = &irlan_eth_netdev_ops;
- dev->destructor = free_netdev;
+ dev->needs_free_netdev = true;
dev->min_mtu = 0;
dev->max_mtu = ETH_MAX_MTU;
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 8b21af7..f7c54ec 100644
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -141,7 +141,7 @@
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
dev->features |= NETIF_F_LLTX;
dev->netdev_ops = &l2tp_eth_netdev_ops;
- dev->destructor = free_netdev;
+ dev->needs_free_netdev = true;
}
static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 8fae1a7..915d7e1 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1213,7 +1213,6 @@
static void ieee80211_if_free(struct net_device *dev)
{
free_percpu(dev->tstats);
- free_netdev(dev);
}
static void ieee80211_if_setup(struct net_device *dev)
@@ -1221,7 +1220,8 @@
ether_setup(dev);
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
dev->netdev_ops = &ieee80211_dataif_ops;
- dev->destructor = ieee80211_if_free;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = ieee80211_if_free;
}
static void ieee80211_if_setup_no_queue(struct net_device *dev)
@@ -1905,7 +1905,7 @@
ret = register_netdevice(ndev);
if (ret) {
- ieee80211_if_free(ndev);
+ free_netdev(ndev);
return ret;
}
}
diff --git a/net/mac802154/iface.c b/net/mac802154/iface.c
index 06019db..bd88a9b 100644
--- a/net/mac802154/iface.c
+++ b/net/mac802154/iface.c
@@ -526,8 +526,6 @@
struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
mac802154_llsec_destroy(&sdata->sec);
-
- free_netdev(dev);
}
static void ieee802154_if_setup(struct net_device *dev)
@@ -593,7 +591,8 @@
sdata->dev->dev_addr);
sdata->dev->header_ops = &mac802154_header_ops;
- sdata->dev->destructor = mac802154_wpan_free;
+ sdata->dev->needs_free_netdev = true;
+ sdata->dev->priv_destructor = mac802154_wpan_free;
sdata->dev->netdev_ops = &mac802154_wpan_ops;
sdata->dev->ml_priv = &mac802154_mlme_wpan;
wpan_dev->promiscuous_mode = false;
@@ -608,7 +607,7 @@
break;
case NL802154_IFTYPE_MONITOR:
- sdata->dev->destructor = free_netdev;
+ sdata->dev->needs_free_netdev = true;
sdata->dev->netdev_ops = &mac802154_monitor_ops;
wpan_dev->promiscuous_mode = true;
break;
diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c
index 89193a6..04a3128 100644
--- a/net/openvswitch/vport-internal_dev.c
+++ b/net/openvswitch/vport-internal_dev.c
@@ -94,7 +94,6 @@
struct vport *vport = ovs_internal_dev_get_vport(dev);
ovs_vport_free(vport);
- free_netdev(dev);
}
static void
@@ -156,7 +155,8 @@
netdev->priv_flags &= ~IFF_TX_SKB_SHARING;
netdev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_OPENVSWITCH |
IFF_PHONY_HEADROOM | IFF_NO_QUEUE;
- netdev->destructor = internal_dev_destructor;
+ netdev->needs_free_netdev = true;
+ netdev->priv_destructor = internal_dev_destructor;
netdev->ethtool_ops = &internal_dev_ethtool_ops;
netdev->rtnl_link_ops = &internal_dev_link_ops;
diff --git a/net/phonet/pep-gprs.c b/net/phonet/pep-gprs.c
index 21c28b5..2c93379 100644
--- a/net/phonet/pep-gprs.c
+++ b/net/phonet/pep-gprs.c
@@ -236,7 +236,7 @@
dev->tx_queue_len = 10;
dev->netdev_ops = &gprs_netdev_ops;
- dev->destructor = free_netdev;
+ dev->needs_free_netdev = true;
}
/*