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>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 4b4d3c8a1aed..19dc796bb0b8 100644
--- 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]);