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>

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0ec9779..af23291 100644 (file)
--- 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();