[PATCH 3.2 134/221] nl80211: ignore HT/VHT capabilities without QoS/WMM

Ben Hutchings
2015-05-05T02:06:58Z

From: Johannes Berg <johannes.berg@intel.com>

commit 496fcc294daab18799e190c0264863d653588d1f 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>
---
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2650,6 +2650,14 @@ static int nl80211_new_station(struct sk
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)) &&