net: fix creation adjacent device symlinks

__netdev_adjacent_dev_insert may add adjust device of different net
namespace, without proper check it leads to emergence of broken
sysfs links from/to devices in another namespace.
Fix: rewrite netdev_adjacent_is_neigh_list macro as a function,
     move net_eq check into netdev_adjacent_is_neigh_list.
     (thanks David)
     related to: 4c75431ac3

Signed-off-by: Alexander Fomichev <git.user@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexander Y. Fomichev 2014-09-15 14:22:35 +04:00 committed by David S. Miller
parent 95e8b10393
commit 7ce64c79c4

View file

@ -4809,9 +4809,14 @@ static void netdev_adjacent_sysfs_del(struct net_device *dev,
sysfs_remove_link(&(dev->dev.kobj), linkname);
}
#define netdev_adjacent_is_neigh_list(dev, dev_list) \
(dev_list == &dev->adj_list.upper || \
dev_list == &dev->adj_list.lower)
static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
struct net_device *adj_dev,
struct list_head *dev_list)
{
return (dev_list == &dev->adj_list.upper ||
dev_list == &dev->adj_list.lower) &&
net_eq(dev_net(dev), dev_net(adj_dev));
}
static int __netdev_adjacent_dev_insert(struct net_device *dev,
struct net_device *adj_dev,
@ -4841,7 +4846,7 @@ static int __netdev_adjacent_dev_insert(struct net_device *dev,
pr_debug("dev_hold for %s, because of link added from %s to %s\n",
adj_dev->name, dev->name, adj_dev->name);
if (netdev_adjacent_is_neigh_list(dev, dev_list)) {
if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
if (ret)
goto free_adj;
@ -4862,7 +4867,7 @@ static int __netdev_adjacent_dev_insert(struct net_device *dev,
return 0;
remove_symlinks:
if (netdev_adjacent_is_neigh_list(dev, dev_list))
if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
free_adj:
kfree(adj);
@ -4895,8 +4900,7 @@ static void __netdev_adjacent_dev_remove(struct net_device *dev,
if (adj->master)
sysfs_remove_link(&(dev->dev.kobj), "master");
if (netdev_adjacent_is_neigh_list(dev, dev_list) &&
net_eq(dev_net(dev),dev_net(adj_dev)))
if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
list_del_rcu(&adj->list);