| 1 |
commit 4c75431ac3520631f1d9e74aa88407e6374dbbc4 |
| 2 |
Author: Alexander Y. Fomichev <git.user@gmail.com> |
| 3 |
Date: Mon Aug 25 16:26:20 2014 +0400 |
| 4 |
|
| 5 |
net: prevent of emerging cross-namespace symlinks |
| 6 |
|
| 7 |
Code manipulating sysfs symlinks on adjacent net_devices(s) |
| 8 |
currently doesn't take into account that devices potentially |
| 9 |
belong to different namespaces. |
| 10 |
|
| 11 |
This patch trying to fix an issue as follows: |
| 12 |
- check for net_ns before creating / deleting symlink. |
| 13 |
for now only netdev_adjacent_rename_links and |
| 14 |
__netdev_adjacent_dev_remove are affected, afaics |
| 15 |
__netdev_adjacent_dev_insert implies both net_devs |
| 16 |
belong to the same namespace. |
| 17 |
- Drop all existing symlinks to / from all adj_devs before |
| 18 |
switching namespace and recreate them just after. |
| 19 |
|
| 20 |
Signed-off-by: Alexander Y. Fomichev <git.user@gmail.com> |
| 21 |
Signed-off-by: David S. Miller <davem@davemloft.net> |
| 22 |
--- |
| 23 |
net/core/dev.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++- |
| 24 |
1 file changed, 60 insertions(+), 1 deletion(-) |
| 25 |
|
| 26 |
diff --git a/net/core/dev.c b/net/core/dev.c |
| 27 |
index b65a505..66738e9 100644 |
| 28 |
--- a/net/core/dev.c |
| 29 |
+++ b/net/core/dev.c |
| 30 |
@@ -4889,7 +4889,8 @@ static void __netdev_adjacent_dev_remove(struct net_device *dev, |
| 31 |
if (adj->master) |
| 32 |
sysfs_remove_link(&(dev->dev.kobj), "master"); |
| 33 |
|
| 34 |
- if (netdev_adjacent_is_neigh_list(dev, dev_list)) |
| 35 |
+ if (netdev_adjacent_is_neigh_list(dev, dev_list) && |
| 36 |
+ net_eq(dev_net(dev),dev_net(adj_dev))) |
| 37 |
netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list); |
| 38 |
|
| 39 |
list_del_rcu(&adj->list); |
| 40 |
@@ -5159,11 +5160,65 @@ void netdev_upper_dev_unlink(struct net_device *dev, |
| 41 |
} |
| 42 |
EXPORT_SYMBOL(netdev_upper_dev_unlink); |
| 43 |
|
| 44 |
+void netdev_adjacent_add_links(struct net_device *dev) |
| 45 |
+{ |
| 46 |
+ struct netdev_adjacent *iter; |
| 47 |
+ |
| 48 |
+ struct net *net = dev_net(dev); |
| 49 |
+ |
| 50 |
+ list_for_each_entry(iter, &dev->adj_list.upper, list) { |
| 51 |
+ if (!net_eq(net,dev_net(iter->dev))) |
| 52 |
+ continue; |
| 53 |
+ netdev_adjacent_sysfs_add(iter->dev, dev, |
| 54 |
+ &iter->dev->adj_list.lower); |
| 55 |
+ netdev_adjacent_sysfs_add(dev, iter->dev, |
| 56 |
+ &dev->adj_list.upper); |
| 57 |
+ } |
| 58 |
+ |
| 59 |
+ list_for_each_entry(iter, &dev->adj_list.lower, list) { |
| 60 |
+ if (!net_eq(net,dev_net(iter->dev))) |
| 61 |
+ continue; |
| 62 |
+ netdev_adjacent_sysfs_add(iter->dev, dev, |
| 63 |
+ &iter->dev->adj_list.upper); |
| 64 |
+ netdev_adjacent_sysfs_add(dev, iter->dev, |
| 65 |
+ &dev->adj_list.lower); |
| 66 |
+ } |
| 67 |
+} |
| 68 |
+ |
| 69 |
+void netdev_adjacent_del_links(struct net_device *dev) |
| 70 |
+{ |
| 71 |
+ struct netdev_adjacent *iter; |
| 72 |
+ |
| 73 |
+ struct net *net = dev_net(dev); |
| 74 |
+ |
| 75 |
+ list_for_each_entry(iter, &dev->adj_list.upper, list) { |
| 76 |
+ if (!net_eq(net,dev_net(iter->dev))) |
| 77 |
+ continue; |
| 78 |
+ netdev_adjacent_sysfs_del(iter->dev, dev->name, |
| 79 |
+ &iter->dev->adj_list.lower); |
| 80 |
+ netdev_adjacent_sysfs_del(dev, iter->dev->name, |
| 81 |
+ &dev->adj_list.upper); |
| 82 |
+ } |
| 83 |
+ |
| 84 |
+ list_for_each_entry(iter, &dev->adj_list.lower, list) { |
| 85 |
+ if (!net_eq(net,dev_net(iter->dev))) |
| 86 |
+ continue; |
| 87 |
+ netdev_adjacent_sysfs_del(iter->dev, dev->name, |
| 88 |
+ &iter->dev->adj_list.upper); |
| 89 |
+ netdev_adjacent_sysfs_del(dev, iter->dev->name, |
| 90 |
+ &dev->adj_list.lower); |
| 91 |
+ } |
| 92 |
+} |
| 93 |
+ |
| 94 |
void netdev_adjacent_rename_links(struct net_device *dev, char *oldname) |
| 95 |
{ |
| 96 |
struct netdev_adjacent *iter; |
| 97 |
|
| 98 |
+ struct net *net = dev_net(dev); |
| 99 |
+ |
| 100 |
list_for_each_entry(iter, &dev->adj_list.upper, list) { |
| 101 |
+ if (!net_eq(net,dev_net(iter->dev))) |
| 102 |
+ continue; |
| 103 |
netdev_adjacent_sysfs_del(iter->dev, oldname, |
| 104 |
&iter->dev->adj_list.lower); |
| 105 |
netdev_adjacent_sysfs_add(iter->dev, dev, |
| 106 |
@@ -5171,6 +5226,8 @@ void netdev_adjacent_rename_links(struct net_device *dev, char *oldname) |
| 107 |
} |
| 108 |
|
| 109 |
list_for_each_entry(iter, &dev->adj_list.lower, list) { |
| 110 |
+ if (!net_eq(net,dev_net(iter->dev))) |
| 111 |
+ continue; |
| 112 |
netdev_adjacent_sysfs_del(iter->dev, oldname, |
| 113 |
&iter->dev->adj_list.upper); |
| 114 |
netdev_adjacent_sysfs_add(iter->dev, dev, |
| 115 |
@@ -6773,6 +6830,7 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char |
| 116 |
|
| 117 |
/* Send a netdev-removed uevent to the old namespace */ |
| 118 |
kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE); |
| 119 |
+ netdev_adjacent_del_links(dev); |
| 120 |
|
| 121 |
/* Actually switch the network namespace */ |
| 122 |
dev_net_set(dev, net); |
| 123 |
@@ -6787,6 +6845,7 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char |
| 124 |
|
| 125 |
/* Send a netdev-add uevent to the new namespace */ |
| 126 |
kobject_uevent(&dev->dev.kobj, KOBJ_ADD); |
| 127 |
+ netdev_adjacent_add_links(dev); |
| 128 |
|
| 129 |
/* Fixup kobjects */ |
| 130 |
err = device_rename(&dev->dev, dev->name); |
Parent Directory
| 
Revision Log