Commit e44d8fe2 authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Marek Lindner

batman-adv: Disallow regular interface as mesh device

When trying to associate a net_device with another net_device which
already exists, batman-adv assumes that this interface is a fully
initialized batman mesh interface without checking it. The behaviour
when accessing data behind netdev_priv of a random net_device is
undefined and potentially dangerous.
Reported-by: default avatarLinus Lüssing <linus.luessing@ascom.ch>
Signed-off-by: default avatarMarek Lindner <lindner_marek@yahoo.de>
parent 7cefb149
......@@ -79,13 +79,8 @@ static int is_valid_iface(struct net_device *net_dev)
return 0;
/* no batman over batman */
#ifdef HAVE_NET_DEVICE_OPS
if (net_dev->netdev_ops->ndo_start_xmit == interface_tx)
if (softif_is_valid(net_dev))
return 0;
#else
if (net_dev->hard_start_xmit == interface_tx)
return 0;
#endif
/* Device is being bridged */
/* if (net_dev->priv_flags & IFF_BRIDGE_PORT)
......@@ -282,6 +277,8 @@ int hardif_enable_interface(struct hard_iface *hard_iface, char *iface_name)
{
struct bat_priv *bat_priv;
struct batman_packet *batman_packet;
struct net_device *soft_iface;
int ret;
if (hard_iface->if_status != IF_NOT_IN_USE)
goto out;
......@@ -289,18 +286,30 @@ int hardif_enable_interface(struct hard_iface *hard_iface, char *iface_name)
if (!atomic_inc_not_zero(&hard_iface->refcount))
goto out;
hard_iface->soft_iface = dev_get_by_name(&init_net, iface_name);
soft_iface = dev_get_by_name(&init_net, iface_name);
if (!hard_iface->soft_iface) {
hard_iface->soft_iface = softif_create(iface_name);
if (!soft_iface) {
soft_iface = softif_create(iface_name);
if (!hard_iface->soft_iface)
if (!soft_iface) {
ret = -ENOMEM;
goto err;
}
/* dev_get_by_name() increases the reference counter for us */
dev_hold(hard_iface->soft_iface);
dev_hold(soft_iface);
}
if (!softif_is_valid(soft_iface)) {
pr_err("Can't create batman mesh interface %s: "
"already exists as regular interface\n",
soft_iface->name);
dev_put(soft_iface);
ret = -EINVAL;
goto err;
}
hard_iface->soft_iface = soft_iface;
bat_priv = netdev_priv(hard_iface->soft_iface);
hard_iface->packet_len = BAT_PACKET_LEN;
hard_iface->packet_buff = kmalloc(hard_iface->packet_len, GFP_ATOMIC);
......@@ -308,6 +317,7 @@ int hardif_enable_interface(struct hard_iface *hard_iface, char *iface_name)
if (!hard_iface->packet_buff) {
bat_err(hard_iface->soft_iface, "Can't add interface packet "
"(%s): out of memory\n", hard_iface->net_dev->name);
ret = -ENOMEM;
goto err;
}
......@@ -370,7 +380,7 @@ int hardif_enable_interface(struct hard_iface *hard_iface, char *iface_name)
err:
hardif_free_ref(hard_iface);
return -ENOMEM;
return ret;
}
void hardif_disable_interface(struct hard_iface *hard_iface)
......
......@@ -622,6 +622,19 @@ void softif_destroy(struct net_device *soft_iface)
unregister_netdevice(soft_iface);
}
int softif_is_valid(struct net_device *net_dev)
{
#ifdef HAVE_NET_DEVICE_OPS
if (net_dev->netdev_ops->ndo_start_xmit == interface_tx)
return 1;
#else
if (net_dev->hard_start_xmit == interface_tx)
return 1;
#endif
return 0;
}
/* ethtool */
static int bat_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
......
......@@ -31,5 +31,6 @@ void interface_rx(struct net_device *soft_iface,
int hdr_size);
struct net_device *softif_create(char *name);
void softif_destroy(struct net_device *soft_iface);
int softif_is_valid(struct net_device *net_dev);
#endif /* _NET_BATMAN_ADV_SOFT_INTERFACE_H_ */
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