[PATCH 3.18 060/183] cfg80211: Fix 160 MHz channels with 80+80 and 160 MHz drivers

[Greg Kroah-Hartman]

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

------------------

From: Jouni Malinen <jouni@xxxxxxxxxxxxxxxx>

commit 08f6f147773b23b765b94633a8eaa82e7defcf4c upstream.

The VHT supported channel width field is a two bit integer, not a
bitfield. cfg80211_chandef_usable() was interpreting it incorrectly and
ended up rejecting 160 MHz channel width if the driver indicated support
for both 160 and 80+80 MHz channels.

Fixes: 3d9d1d6656a73 ("nl80211/cfg80211: support VHT channel configuration")
       (however, no real drivers had 160 MHz support it until 3.16)
Signed-off-by: Jouni Malinen <jouni@xxxxxxxxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/wireless/chan.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -602,7 +602,7 @@ bool cfg80211_chandef_usable(struct wiph
 {
 	struct ieee80211_sta_ht_cap *ht_cap;
 	struct ieee80211_sta_vht_cap *vht_cap;
-	u32 width, control_freq;
+	u32 width, control_freq, cap;
 
 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 		return false;
@@ -642,7 +642,8 @@ bool cfg80211_chandef_usable(struct wiph
 			return false;
 		break;
 	case NL80211_CHAN_WIDTH_80P80:
-		if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))
+		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
+		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
 			return false;
 	case NL80211_CHAN_WIDTH_80:
 		if (!vht_cap->vht_supported)
@@ -653,7 +654,9 @@ bool cfg80211_chandef_usable(struct wiph
 	case NL80211_CHAN_WIDTH_160:
 		if (!vht_cap->vht_supported)
 			return false;
-		if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ))
+		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
+		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
+		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
 			return false;
 		prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
 		width = 160;


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