veth: prevent oops caused by netdev destructor
From: Stephen Hemminger <shemminger@vyatta.com>
The veth driver will oops if sysfs hooks are open while module is removed.
The net device destructor can not point to code in a module; basically
there are only two possible safe values: NULL - no destructor, or
free_netdev - free on last use
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 015db1c..8e56fcf 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -210,14 +210,11 @@
static struct net_device_stats *veth_get_stats(struct net_device *dev)
{
- struct veth_priv *priv;
- struct net_device_stats *dev_stats;
- int cpu;
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device_stats *dev_stats = &dev->stats;
+ unsigned int cpu;
struct veth_net_stats *stats;
- priv = netdev_priv(dev);
- dev_stats = &dev->stats;
-
dev_stats->rx_packets = 0;
dev_stats->tx_packets = 0;
dev_stats->rx_bytes = 0;
@@ -225,16 +222,17 @@
dev_stats->tx_dropped = 0;
dev_stats->rx_dropped = 0;
- for_each_online_cpu(cpu) {
- stats = per_cpu_ptr(priv->stats, cpu);
+ if (priv->stats)
+ for_each_online_cpu(cpu) {
+ stats = per_cpu_ptr(priv->stats, cpu);
- dev_stats->rx_packets += stats->rx_packets;
- dev_stats->tx_packets += stats->tx_packets;
- dev_stats->rx_bytes += stats->rx_bytes;
- dev_stats->tx_bytes += stats->tx_bytes;
- dev_stats->tx_dropped += stats->tx_dropped;
- dev_stats->rx_dropped += stats->rx_dropped;
- }
+ dev_stats->rx_packets += stats->rx_packets;
+ dev_stats->tx_packets += stats->tx_packets;
+ dev_stats->rx_bytes += stats->rx_bytes;
+ dev_stats->tx_bytes += stats->tx_bytes;
+ dev_stats->tx_dropped += stats->tx_dropped;
+ dev_stats->rx_dropped += stats->rx_dropped;
+ }
return dev_stats;
}
@@ -261,6 +259,8 @@
netif_carrier_off(dev);
netif_carrier_off(priv->peer);
+ free_percpu(priv->stats);
+ priv->stats = NULL;
return 0;
}
@@ -291,15 +291,6 @@
return 0;
}
-static void veth_dev_free(struct net_device *dev)
-{
- struct veth_priv *priv;
-
- priv = netdev_priv(dev);
- free_percpu(priv->stats);
- free_netdev(dev);
-}
-
static const struct net_device_ops veth_netdev_ops = {
.ndo_init = veth_dev_init,
.ndo_open = veth_open,
@@ -317,7 +308,7 @@
dev->netdev_ops = &veth_netdev_ops;
dev->ethtool_ops = &veth_ethtool_ops;
dev->features |= NETIF_F_LLTX;
- dev->destructor = veth_dev_free;
+ dev->destructor = free_netdev;
}
/*