nl80211: ignore HT/VHT capabilities without QoS/WMM

commit 496fcc29 upstream.

As HT/VHT depend heavily on QoS/WMM, it's not a good idea to
let userspace add clients that have HT/VHT but not QoS/WMM.
Since it does so in certain cases we've observed (client is
using HT IEs but not QoS/WMM) just ignore the HT/VHT info at
this point and don't pass it down to the drivers which might
unconditionally use it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[bwh: Backported to 3.2:
 - Adjust context
 - VHT is not supported]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

net/wireless/nl80211.c

@@ -2650,6 +2650,14 @@ static int nl80211_new_station(struct sk_buff *skb, struct genl_info *info)
 	if (parse_station_flags(info, &params))
 		return -EINVAL;
 
+	/* HT requires QoS, but if we don't have that just ignore HT/VHT
+	 * as userspace might just pass through the capabilities from the IEs
+	 * directly, rather than enforcing this restriction and returning an
+	 * error in this case.
+	 */
+	if (!(params.sta_flags_set & BIT(NL80211_STA_FLAG_WME)))
+		params.ht_capa = NULL;
+
 	/* parse WME attributes if sta is WME capable */
 	if ((rdev->wiphy.flags & WIPHY_FLAG_AP_UAPSD) &&
 	    (params.sta_flags_set & BIT(NL80211_STA_FLAG_WME)) &&