nl80211: fix netns separation

There are currently a few ways to "escape"
the network namespace and access a wiphy
that belongs to another namespace. Add a
netns argument to the relevant functions
to fix this.

One remaining issue with testmode will be
fixed in a follow-up patch.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 12 insertions, 9 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0ec9779c2b56..af232912fff8 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -71,7 +71,7 @@ static int get_rdev_dev_by_ifindex(struct net *netns, struct nlattr **attrs,
 }
 
 static struct cfg80211_registered_device *
-__cfg80211_rdev_from_info(struct genl_info *info)
+__cfg80211_rdev_from_info(struct net *netns, struct genl_info *info)
 {
         struct cfg80211_registered_device *rdev = NULL, *tmp;
         struct net_device *netdev;
@@ -88,7 +88,7 @@ __cfg80211_rdev_from_info(struct genl_info *info)
 
         if (info->attrs[NL80211_ATTR_IFINDEX]) {
                 int ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
-                netdev = dev_get_by_index(genl_info_net(info), ifindex);
+                netdev = dev_get_by_index(netns, ifindex);
                 if (netdev) {
                         if (netdev->ieee80211_ptr)
                                 tmp = wiphy_to_dev(
@@ -110,10 +110,13 @@ __cfg80211_rdev_from_info(struct genl_info *info)
                 }
         }
 
-        if (rdev)
-                return rdev;
+        if (!rdev)
+                return ERR_PTR(-ENODEV);
 
-        return ERR_PTR(-ENODEV);
+        if (netns != wiphy_net(&rdev->wiphy))
+                return ERR_PTR(-ENODEV);
+
+        return rdev;
 }
 
 /*
@@ -137,12 +140,12 @@ __cfg80211_rdev_from_info(struct genl_info *info)
  * be checked with IS_ERR() for errors.
  */
 static struct cfg80211_registered_device *
-cfg80211_get_dev_from_info(struct genl_info *info)
+cfg80211_get_dev_from_info(struct net *netns, struct genl_info *info)
 {
         struct cfg80211_registered_device *rdev;
 
         mutex_lock(&cfg80211_mutex);
-        rdev = __cfg80211_rdev_from_info(info);
+        rdev = __cfg80211_rdev_from_info(netns, info);
 
         /* if it is not an error we grab the lock on
          * it to assure it won't be going away while
@@ -1419,7 +1422,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
         }
 
         if (!netdev) {
-                rdev = __cfg80211_rdev_from_info(info);
+                rdev = __cfg80211_rdev_from_info(genl_info_net(info), info);
                 if (IS_ERR(rdev)) {
                         mutex_unlock(&cfg80211_mutex);
                         return PTR_ERR(rdev);
@@ -6623,7 +6626,7 @@ static int nl80211_pre_doit(struct genl_ops *ops, struct sk_buff *skb,
                 rtnl_lock();
 
         if (ops->internal_flags & NL80211_FLAG_NEED_WIPHY) {
-                rdev = cfg80211_get_dev_from_info(info);
+                rdev = cfg80211_get_dev_from_info(genl_info_net(info), info);
                 if (IS_ERR(rdev)) {
                         if (rtnl)
                                 rtnl_unlock();