[3.16.y-ckt stable] Patch "nl80211: ignore HT/VHT capabilities without QoS/WMM" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    nl80211: ignore HT/VHT capabilities without QoS/WMM

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt10.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 4adc33dc862474f8f5df0df9587e427e6386f973 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg at intel.com>
Date: Thu, 12 Mar 2015 08:53:27 +0200
Subject: nl80211: ignore HT/VHT capabilities without QoS/WMM

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 at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/wireless/nl80211.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index be4ba21df4d8..d316a9568238 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4266,6 +4266,16 @@ 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 */
 	BUILD_BUG_ON(NL80211_STA_FLAG_MAX != 7);