[PATCH 3.14 95/98] net: fix creation adjacent device symlinks

Greg Kroah-Hartman
2015-01-25T19:08:08Z

From: "Alexander Y. Fomichev" <git.user@gmail.com>

commit 7ce64c79c4decdeb1afe0bf2f6ef834b382871d1 upstream.

__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: 4c75431ac3520631f1d9e74aa88407e6374dbbc4

Signed-off-by: Alexander Fomichev <git.user@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Miquel van Smoorenburg <mikevs@xs4all.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/core/dev.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4705,9 +4705,14 @@ static void netdev_adjacent_sysfs_del(st
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,
@@ -4737,7 +4742,7 @@ static int __netdev_adjacent_dev_insert(
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;
@@ -4758,7 +4763,7 @@ static int __netdev_adjacent_dev_insert(
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);
@@ -4791,8 +4796,7 @@ static void __netdev_adjacent_dev_remove
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);