1 files changed, 28 insertions, 12 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index ca75f60..0f1b18f2 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1928,18 +1928,20 @@ static int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
 }
 
 static int __nl80211_set_channel(struct cfg80211_registered_device *rdev,
-				 struct wireless_dev *wdev,
+				 struct net_device *dev,
 				 struct genl_info *info)
 {
 	struct cfg80211_chan_def chandef;
 	int result;
 	enum nl80211_iftype iftype = NL80211_IFTYPE_MONITOR;
+	struct wireless_dev *wdev = NULL;
 
-	if (wdev)
-		iftype = wdev->iftype;
-
+	if (dev)
+		wdev = dev->ieee80211_ptr;
 	if (!nl80211_can_set_dev_channel(wdev))
 		return -EOPNOTSUPP;
+	if (wdev)
+		iftype = wdev->iftype;
 
 	result = nl80211_parse_chandef(rdev, info, &chandef);
 	if (result)
@@ -1948,14 +1950,27 @@ static int __nl80211_set_channel(struct cfg80211_registered_device *rdev,
 	switch (iftype) {
 	case NL80211_IFTYPE_AP:
 	case NL80211_IFTYPE_P2P_GO:
-		if (wdev->beacon_interval) {
-			result = -EBUSY;
-			break;
-		}
 		if (!cfg80211_reg_can_beacon(&rdev->wiphy, &chandef, iftype)) {
 			result = -EINVAL;
 			break;
 		}
+		if (wdev->beacon_interval) {
+			if (!dev || !rdev->ops->set_ap_chanwidth ||
+			    !(rdev->wiphy.features &
+			      NL80211_FEATURE_AP_MODE_CHAN_WIDTH_CHANGE)) {
+				result = -EBUSY;
+				break;
+			}
+
+			/* Only allow dynamic channel width changes */
+			if (chandef.chan != wdev->preset_chandef.chan) {
+				result = -EBUSY;
+				break;
+			}
+			result = rdev_set_ap_chanwidth(rdev, dev, &chandef);
+			if (result)
+				break;
+		}
 		wdev->preset_chandef = chandef;
 		result = 0;
 		break;
@@ -1977,7 +1992,7 @@ static int nl80211_set_channel(struct sk_buff *skb, struct genl_info *info)
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
 	struct net_device *netdev = info->user_ptr[1];
 
-	return __nl80211_set_channel(rdev, netdev->ieee80211_ptr, info);
+	return __nl80211_set_channel(rdev, netdev, info);
 }
 
 static int nl80211_set_wds_peer(struct sk_buff *skb, struct genl_info *info)
@@ -2099,9 +2114,10 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
-		result = __nl80211_set_channel(rdev,
-				nl80211_can_set_dev_channel(wdev) ? wdev : NULL,
-				info);
+		result = __nl80211_set_channel(
+			rdev,
+			nl80211_can_set_dev_channel(wdev) ? netdev : NULL,
+			info);
 		if (result)
 			return result;
 	}