cfg80211: validate AID of stations being added

We have some validation code in mac80211 but said code will
force an invalid AID to 0 which isn't a valid AID either;
instead require a valid AID (1-2007) to be passed in from
userspace in cfg80211 already. Also move the code before
the race comment since it can only be executed during STA
addition and thus is not racy.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 77e9ff5..cdfdb2e 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -664,18 +664,19 @@ static void sta_apply_parameters(struct ieee80211_local *local,
        spin_unlock_bh(&sta->lock);
 
        /*
+        * cfg80211 validates this (1-2007) and allows setting the AID
+        * only when creating a new station entry
+        */
+       if (params->aid)
+               sta->sta.aid = params->aid;
+
+       /*
         * FIXME: updating the following information is racy when this
         *        function is called from ieee80211_change_station().
         *        However, all this information should be static so
         *        maybe we should just reject attemps to change it.
         */
 
-       if (params->aid) {
-               sta->sta.aid = params->aid;
-               if (sta->sta.aid > IEEE80211_MAX_AID)
-                       sta->sta.aid = 0; /* XXX: should this be an error? */
-       }
-
        if (params->listen_interval >= 0)
                sta->listen_interval = params->listen_interval;
 

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 4b4d3c8..19dc796 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1738,7 +1738,11 @@ static int nl80211_new_station(struct sk_buff *skb, struct genl_info *info)
                nla_len(info->attrs[NL80211_ATTR_STA_SUPPORTED_RATES]);
        params.listen_interval =
                nla_get_u16(info->attrs[NL80211_ATTR_STA_LISTEN_INTERVAL]);
+
        params.aid = nla_get_u16(info->attrs[NL80211_ATTR_STA_AID]);
+       if (!params.aid || params.aid > IEEE80211_MAX_AID)
+               return -EINVAL;
+
        if (info->attrs[NL80211_ATTR_HT_CAPABILITY])
                params.ht_capa =
                        nla_data(info->attrs[NL80211_ATTR_HT_CAPABILITY]);