[PATCH 3.13.y-ckt 129/156] nl80211: ignore HT/VHT capabilities without QoS/WMM

From: Kamal Mostafa
Date: Tue Apr 07 2015 - 19:03:41 EST

3.13.11-ckt19 -stable review patch. If anyone has any objections, please let me know.


From: Johannes Berg <johannes.berg@xxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
net/wireless/nl80211.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 30caa5c..37f1ddc 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4162,6 +4162,16 @@ static int nl80211_new_station(struct sk_buff *skb, struct genl_info *info)
if (parse_station_flags(info, dev->ieee80211_ptr->iftype, &params))
return -EINVAL;

+ /* HT/VHT 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;
+ params.vht_capa = NULL;
+ }
/* When you run into this, adjust the code below for the new flag */


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