Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/linville/wireless-2.6.26

7 files changed, 204 insertions, 96 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 8af576c..699d97b 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -33,6 +33,8 @@ nl80211_type_to_mac80211_type(enum nl80211_iftype type)
 	case NL80211_IFTYPE_MESH_POINT:
 		return IEEE80211_IF_TYPE_MESH_POINT;
 #endif
+	case NL80211_IFTYPE_WDS:
+		return IEEE80211_IF_TYPE_WDS;
 	default:
 		return IEEE80211_IF_TYPE_INVALID;
 	}
@@ -718,12 +720,18 @@ static int ieee80211_del_station(struct wiphy *wiphy, struct net_device *dev,
 	struct sta_info *sta;
 
 	if (mac) {
+		rcu_read_lock();
+
 		/* XXX: get sta belonging to dev */
 		sta = sta_info_get(local, mac);
-		if (!sta)
+		if (!sta) {
+			rcu_read_unlock();
 			return -ENOENT;
+		}
 
 		sta_info_unlink(&sta);
+		rcu_read_unlock();
+
 		sta_info_destroy(sta);
 	} else
 		sta_info_flush(local, sdata);
@@ -740,17 +748,23 @@ static int ieee80211_change_station(struct wiphy *wiphy,
 	struct sta_info *sta;
 	struct ieee80211_sub_if_data *vlansdata;
 
+	rcu_read_lock();
+
 	/* XXX: get sta belonging to dev */
 	sta = sta_info_get(local, mac);
-	if (!sta)
+	if (!sta) {
+		rcu_read_unlock();
 		return -ENOENT;
+	}
 
 	if (params->vlan && params->vlan != sta->sdata->dev) {
 		vlansdata = IEEE80211_DEV_TO_SUB_IF(params->vlan);
 
 		if (vlansdata->vif.type != IEEE80211_IF_TYPE_VLAN ||
-		    vlansdata->vif.type != IEEE80211_IF_TYPE_AP)
+		    vlansdata->vif.type != IEEE80211_IF_TYPE_AP) {
+			rcu_read_unlock();
 			return -EINVAL;
+		}
 
 		sta->sdata = IEEE80211_DEV_TO_SUB_IF(params->vlan);
 		ieee80211_send_layer2_update(sta);
@@ -758,6 +772,8 @@ static int ieee80211_change_station(struct wiphy *wiphy,
 
 	sta_apply_parameters(local, sta, params);
 
+	rcu_read_unlock();
+
 	return 0;
 }
 
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c642538..8e53ce7 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -102,7 +102,7 @@ struct ieee80211_sta_bss {
 	u64 timestamp;
 	int beacon_int;
 
-	int probe_resp;
+	bool probe_resp;
 	unsigned long last_update;
 
 	/* during assocation, we save an ERP value from a probe response so
@@ -600,8 +600,7 @@ struct ieee80211_local {
 	/*
 	 * The lock only protects the list, hash, timer and counter
 	 * against manipulation, reads are done in RCU. Additionally,
-	 * the lock protects each BSS's TIM bitmap, a few items in
-	 * STA info structures and various key pointers.
+	 * the lock protects each BSS's TIM bitmap.
 	 */
 	spinlock_t sta_lock;
 	unsigned long num_sta;
@@ -635,6 +634,13 @@ struct ieee80211_local {
 
 	struct list_head interfaces;
 
+	/*
+	 * Key lock, protects sdata's key_list and sta_info's
+	 * key pointers (write access, they're RCU.)
+	 */
+	spinlock_t key_lock;
+
+
 	bool sta_sw_scanning;
 	bool sta_hw_scanning;
 	int scan_channel_idx;
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index 711e36e..150d66d 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -74,9 +74,12 @@ static void add_todo(struct ieee80211_key *key, u32 flag)
 
 	spin_lock(&todo_lock);
 	key->flags |= flag;
-	/* only add if not already added */
-	if (list_empty(&key->todo))
-		list_add(&key->todo, &todo_list);
+	/*
+	 * Remove again if already on the list so that we move it to the end.
+	 */
+	if (!list_empty(&key->todo))
+		list_del(&key->todo);
+	list_add_tail(&key->todo, &todo_list);
 	schedule_work(&todo_work);
 	spin_unlock(&todo_lock);
 }
@@ -210,9 +213,9 @@ void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&sdata->local->sta_lock, flags);
+	spin_lock_irqsave(&sdata->local->key_lock, flags);
 	__ieee80211_set_default_key(sdata, idx);
-	spin_unlock_irqrestore(&sdata->local->sta_lock, flags);
+	spin_unlock_irqrestore(&sdata->local->key_lock, flags);
 }
 
 
@@ -339,7 +342,7 @@ void ieee80211_key_link(struct ieee80211_key *key,
 		}
 	}
 
-	spin_lock_irqsave(&sdata->local->sta_lock, flags);
+	spin_lock_irqsave(&sdata->local->key_lock, flags);
 
 	if (sta)
 		old_key = sta->key;
@@ -348,68 +351,81 @@ void ieee80211_key_link(struct ieee80211_key *key,
 
 	__ieee80211_key_replace(sdata, sta, old_key, key);
 
-	spin_unlock_irqrestore(&sdata->local->sta_lock, flags);
+	spin_unlock_irqrestore(&sdata->local->key_lock, flags);
 
 	/* free old key later */
 	add_todo(old_key, KEY_FLAG_TODO_DELETE);
 
 	add_todo(key, KEY_FLAG_TODO_ADD_DEBUGFS);
 	if (netif_running(sdata->dev))
-		add_todo(key, KEY_FLAG_TODO_HWACCEL);
+		add_todo(key, KEY_FLAG_TODO_HWACCEL_ADD);
 }
 
-void ieee80211_key_free(struct ieee80211_key *key)
+static void __ieee80211_key_free(struct ieee80211_key *key)
 {
-	unsigned long flags;
-
-	if (!key)
-		return;
-
 	/*
 	 * Replace key with nothingness if it was ever used.
 	 */
-	if (key->sdata) {
-		spin_lock_irqsave(&key->sdata->local->sta_lock, flags);
+	if (key->sdata)
 		__ieee80211_key_replace(key->sdata, key->sta,
 					key, NULL);
-		spin_unlock_irqrestore(&key->sdata->local->sta_lock, flags);
-	}
 
 	add_todo(key, KEY_FLAG_TODO_DELETE);
 }
 
-void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
+void ieee80211_key_free(struct ieee80211_key *key)
 {
-	struct ieee80211_key *key;
-
-	might_sleep();
+	unsigned long flags;
 
-	if (WARN_ON(!netif_running(sdata->dev)))
+	if (!key)
 		return;
 
-	ieee80211_key_lock();
+	spin_lock_irqsave(&key->sdata->local->key_lock, flags);
+	__ieee80211_key_free(key);
+	spin_unlock_irqrestore(&key->sdata->local->key_lock, flags);
+}
+
+/*
+ * To be safe against concurrent manipulations of the list (which shouldn't
+ * actually happen) we need to hold the spinlock. But under the spinlock we
+ * can't actually do much, so we defer processing to the todo list. Then run
+ * the todo list to be sure the operation and possibly previously pending
+ * operations are completed.
+ */
+static void ieee80211_todo_for_each_key(struct ieee80211_sub_if_data *sdata,
+					u32 todo_flags)
+{
+	struct ieee80211_key *key;
+	unsigned long flags;
 
+	might_sleep();
+
+	spin_lock_irqsave(&sdata->local->key_lock, flags);
 	list_for_each_entry(key, &sdata->key_list, list)
-		ieee80211_key_enable_hw_accel(key);
+		add_todo(key, todo_flags);
+	spin_unlock_irqrestore(&sdata->local->key_lock, flags);
 
-	ieee80211_key_unlock();
+	ieee80211_key_todo();
 }
 
-void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
+void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
 {
-	struct ieee80211_key *key;
+	ASSERT_RTNL();
 
-	might_sleep();
+	if (WARN_ON(!netif_running(sdata->dev)))
+		return;
 
-	ieee80211_key_lock();
+	ieee80211_todo_for_each_key(sdata, KEY_FLAG_TODO_HWACCEL_ADD);
+}
 
-	list_for_each_entry(key, &sdata->key_list, list)
-		ieee80211_key_disable_hw_accel(key);
+void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
+{
+	ASSERT_RTNL();
 
-	ieee80211_key_unlock();
+	ieee80211_todo_for_each_key(sdata, KEY_FLAG_TODO_HWACCEL_REMOVE);
 }
 
-static void __ieee80211_key_free(struct ieee80211_key *key)
+static void __ieee80211_key_destroy(struct ieee80211_key *key)
 {
 	if (!key)
 		return;
@@ -440,7 +456,8 @@ static void __ieee80211_key_todo(void)
 		list_del_init(&key->todo);
 		todoflags = key->flags & (KEY_FLAG_TODO_ADD_DEBUGFS |
 					  KEY_FLAG_TODO_DEFKEY |
-					  KEY_FLAG_TODO_HWACCEL |
+					  KEY_FLAG_TODO_HWACCEL_ADD |
+					  KEY_FLAG_TODO_HWACCEL_REMOVE |
 					  KEY_FLAG_TODO_DELETE);
 		key->flags &= ~todoflags;
 		spin_unlock(&todo_lock);
@@ -456,12 +473,16 @@ static void __ieee80211_key_todo(void)
 			ieee80211_debugfs_key_add_default(key->sdata);
 			work_done = true;
 		}
-		if (todoflags & KEY_FLAG_TODO_HWACCEL) {
+		if (todoflags & KEY_FLAG_TODO_HWACCEL_ADD) {
 			ieee80211_key_enable_hw_accel(key);
 			work_done = true;
 		}
+		if (todoflags & KEY_FLAG_TODO_HWACCEL_REMOVE) {
+			ieee80211_key_disable_hw_accel(key);
+			work_done = true;
+		}
 		if (todoflags & KEY_FLAG_TODO_DELETE) {
-			__ieee80211_key_free(key);
+			__ieee80211_key_destroy(key);
 			work_done = true;
 		}
 
@@ -482,14 +503,16 @@ void ieee80211_key_todo(void)
 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_key *key, *tmp;
-	LIST_HEAD(tmp_list);
+	unsigned long flags;
 
 	ieee80211_key_lock();
 
 	ieee80211_debugfs_key_remove_default(sdata);
 
+	spin_lock_irqsave(&sdata->local->key_lock, flags);
 	list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
-		ieee80211_key_free(key);
+		__ieee80211_key_free(key);
+	spin_unlock_irqrestore(&sdata->local->key_lock, flags);
 
 	__ieee80211_key_todo();
 
diff --git a/net/mac80211/key.h b/net/mac80211/key.h
index 5d48518..f52c3df 100644
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -54,16 +54,19 @@ struct sta_info;
  * @KEY_FLAG_TODO_DELETE: Key is marked for deletion and will, after an
  *	RCU grace period, no longer be reachable other than from the
  *	todo list.
- * @KEY_FLAG_TODO_HWACCEL: Key needs to be added to hardware acceleration.
+ * @KEY_FLAG_TODO_HWACCEL_ADD: Key needs to be added to hardware acceleration.
+ * @KEY_FLAG_TODO_HWACCEL_REMOVE: Key needs to be removed from hardware
+ *	acceleration.
  * @KEY_FLAG_TODO_DEFKEY: Key is default key and debugfs needs to be updated.
  * @KEY_FLAG_TODO_ADD_DEBUGFS: Key needs to be added to debugfs.
  */
 enum ieee80211_internal_key_flags {
 	KEY_FLAG_UPLOADED_TO_HARDWARE	= BIT(0),
 	KEY_FLAG_TODO_DELETE		= BIT(1),
-	KEY_FLAG_TODO_HWACCEL		= BIT(2),
-	KEY_FLAG_TODO_DEFKEY		= BIT(3),
-	KEY_FLAG_TODO_ADD_DEBUGFS	= BIT(4),
+	KEY_FLAG_TODO_HWACCEL_ADD	= BIT(2),
+	KEY_FLAG_TODO_HWACCEL_REMOVE	= BIT(3),
+	KEY_FLAG_TODO_DEFKEY		= BIT(4),
+	KEY_FLAG_TODO_ADD_DEBUGFS	= BIT(5),
 };
 
 struct ieee80211_key {
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index bfcbcf5..e9a9789 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1587,6 +1587,8 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 
 	INIT_LIST_HEAD(&local->interfaces);
 
+	spin_lock_init(&local->key_lock);
+
 	INIT_DELAYED_WORK(&local->scan_work, ieee80211_sta_scan_work);
 
 	sta_info_init(local);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index bdaab13..6b75cb6 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -350,14 +350,12 @@ static void ieee80211_sta_wmm_params(struct net_device *dev,
 	}
 }
 
-
-static u32 ieee80211_handle_erp_ie(struct ieee80211_sub_if_data *sdata,
-				   u8 erp_value)
+static u32 ieee80211_handle_protect_preamb(struct ieee80211_sub_if_data *sdata,
+					   bool use_protection,
+					   bool use_short_preamble)
 {
 	struct ieee80211_bss_conf *bss_conf = &sdata->bss_conf;
 	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
-	bool use_protection = (erp_value & WLAN_ERP_USE_PROTECTION) != 0;
-	bool use_short_preamble = (erp_value & WLAN_ERP_BARKER_PREAMBLE) == 0;
 	DECLARE_MAC_BUF(mac);
 	u32 changed = 0;
 
@@ -388,6 +386,32 @@ static u32 ieee80211_handle_erp_ie(struct ieee80211_sub_if_data *sdata,
 	return changed;
 }
 
+static u32 ieee80211_handle_erp_ie(struct ieee80211_sub_if_data *sdata,
+				   u8 erp_value)
+{
+	bool use_protection = (erp_value & WLAN_ERP_USE_PROTECTION) != 0;
+	bool use_short_preamble = (erp_value & WLAN_ERP_BARKER_PREAMBLE) == 0;
+
+	return ieee80211_handle_protect_preamb(sdata,
+			use_protection, use_short_preamble);
+}
+
+static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,
+					   struct ieee80211_sta_bss *bss)
+{
+	u32 changed = 0;
+
+	if (bss->has_erp_value)
+		changed |= ieee80211_handle_erp_ie(sdata, bss->erp_value);
+	else {
+		u16 capab = bss->capability;
+		changed |= ieee80211_handle_protect_preamb(sdata, false,
+				(capab & WLAN_CAPABILITY_SHORT_PREAMBLE) != 0);
+	}
+
+	return changed;
+}
+
 int ieee80211_ht_cap_ie_to_ht_info(struct ieee80211_ht_cap *ht_cap_ie,
 				   struct ieee80211_ht_info *ht_info)
 {
@@ -511,9 +535,7 @@ static void ieee80211_set_associated(struct net_device *dev,
 			sdata->bss_conf.beacon_int = bss->beacon_int;
 			sdata->bss_conf.timestamp = bss->timestamp;
 
-			if (bss->has_erp_value)
-				changed |= ieee80211_handle_erp_ie(
-						sdata, bss->erp_value);
+			changed |= ieee80211_handle_bss_capability(sdata, bss);
 
 			ieee80211_rx_bss_put(dev, bss);
 		}
@@ -2566,22 +2588,29 @@ static void ieee80211_rx_bss_info(struct net_device *dev,
 #endif
 	}
 
-	bss->band = rx_status->band;
-
-	if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
-	    bss->probe_resp && beacon) {
-		/* STA mode:
-		 * Do not allow beacon to override data from Probe Response. */
-		ieee80211_rx_bss_put(dev, bss);
-		return;
-	}
-
 	/* save the ERP value so that it is available at association time */
 	if (elems.erp_info && elems.erp_info_len >= 1) {
 		bss->erp_value = elems.erp_info[0];
 		bss->has_erp_value = 1;
 	}
 
+	if (elems.ht_cap_elem &&
+	     (!bss->ht_ie || bss->ht_ie_len != elems.ht_cap_elem_len ||
+	     memcmp(bss->ht_ie, elems.ht_cap_elem, elems.ht_cap_elem_len))) {
+		kfree(bss->ht_ie);
+		bss->ht_ie = kmalloc(elems.ht_cap_elem_len + 2, GFP_ATOMIC);
+		if (bss->ht_ie) {
+			memcpy(bss->ht_ie, elems.ht_cap_elem - 2,
+				elems.ht_cap_elem_len + 2);
+			bss->ht_ie_len = elems.ht_cap_elem_len + 2;
+		} else
+			bss->ht_ie_len = 0;
+	} else if (!elems.ht_cap_elem && bss->ht_ie) {
+		kfree(bss->ht_ie);
+		bss->ht_ie = NULL;
+		bss->ht_ie_len = 0;
+	}
+
 	bss->beacon_int = le16_to_cpu(mgmt->u.beacon.beacon_int);
 	bss->capability = le16_to_cpu(mgmt->u.beacon.capab_info);
 
@@ -2603,6 +2632,26 @@ static void ieee80211_rx_bss_info(struct net_device *dev,
 		bss->supp_rates_len += clen;
 	}
 
+	bss->band = rx_status->band;
+
+	bss->timestamp = beacon_timestamp;
+	bss->last_update = jiffies;
+	bss->rssi = rx_status->ssi;
+	bss->signal = rx_status->signal;
+	bss->noise = rx_status->noise;
+	if (!beacon && !bss->probe_resp)
+		bss->probe_resp = true;
+
+	/*
+	 * In STA mode, the remaining parameters should not be overridden
+	 * by beacons because they're not necessarily accurate there.
+	 */
+	if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
+	    bss->probe_resp && beacon) {
+		ieee80211_rx_bss_put(dev, bss);
+		return;
+	}
+
 	if (elems.wpa &&
 	    (!bss->wpa_ie || bss->wpa_ie_len != elems.wpa_len ||
 	     memcmp(bss->wpa_ie, elems.wpa, elems.wpa_len))) {
@@ -2635,6 +2684,20 @@ static void ieee80211_rx_bss_info(struct net_device *dev,
 		bss->rsn_ie_len = 0;
 	}
 
+	/*
+	 * Cf.
+	 * http://www.wipo.int/pctdb/en/wo.jsp?wo=2007047181&IA=WO2007047181&DISPLAY=DESC
+	 *
+	 * quoting:
+	 *
+	 * In particular, "Wi-Fi CERTIFIED for WMM - Support for Multimedia
+	 * Applications with Quality of Service in Wi-Fi Networks," Wi- Fi
+	 * Alliance (September 1, 2004) is incorporated by reference herein.
+	 * The inclusion of the WMM Parameters in probe responses and
+	 * association responses is mandatory for WMM enabled networks. The
+	 * inclusion of the WMM Parameters in beacons, however, is optional.
+	 */
+
 	if (elems.wmm_param &&
 	    (!bss->wmm_ie || bss->wmm_ie_len != elems.wmm_param_len ||
 	     memcmp(bss->wmm_ie, elems.wmm_param, elems.wmm_param_len))) {
@@ -2651,30 +2714,6 @@ static void ieee80211_rx_bss_info(struct net_device *dev,
 		bss->wmm_ie = NULL;
 		bss->wmm_ie_len = 0;
 	}
-	if (elems.ht_cap_elem &&
-	    (!bss->ht_ie || bss->ht_ie_len != elems.ht_cap_elem_len ||
-	     memcmp(bss->ht_ie, elems.ht_cap_elem, elems.ht_cap_elem_len))) {
-		kfree(bss->ht_ie);
-		bss->ht_ie = kmalloc(elems.ht_cap_elem_len + 2, GFP_ATOMIC);
-		if (bss->ht_ie) {
-			memcpy(bss->ht_ie, elems.ht_cap_elem - 2,
-			       elems.ht_cap_elem_len + 2);
-			bss->ht_ie_len = elems.ht_cap_elem_len + 2;
-		} else
-			bss->ht_ie_len = 0;
-	} else if (!elems.ht_cap_elem && bss->ht_ie) {
-		kfree(bss->ht_ie);
-		bss->ht_ie = NULL;
-		bss->ht_ie_len = 0;
-	}
-
-	bss->timestamp = beacon_timestamp;
-	bss->last_update = jiffies;
-	bss->rssi = rx_status->ssi;
-	bss->signal = rx_status->signal;
-	bss->noise = rx_status->noise;
-	if (!beacon)
-		bss->probe_resp++;
 
 	/* check if we need to merge IBSS */
 	if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && beacon &&
@@ -2775,8 +2814,24 @@ static void ieee80211_rx_mgmt_beacon(struct net_device *dev,
 
 	ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 
+	if (elems.wmm_param && (ifsta->flags & IEEE80211_STA_WMM_ENABLED)) {
+		ieee80211_sta_wmm_params(dev, ifsta, elems.wmm_param,
+					 elems.wmm_param_len);
+	}
+
+	/* Do not send changes to driver if we are scanning. This removes
+	 * requirement that driver's bss_info_changed function needs to be
+	 * atomic. */
+	if (local->sta_sw_scanning || local->sta_hw_scanning)
+		return;
+
 	if (elems.erp_info && elems.erp_info_len >= 1)
 		changed |= ieee80211_handle_erp_ie(sdata, elems.erp_info[0]);
+	else {
+		u16 capab = le16_to_cpu(mgmt->u.beacon.capab_info);
+		changed |= ieee80211_handle_protect_preamb(sdata, false,
+				(capab & WLAN_CAPABILITY_SHORT_PREAMBLE) != 0);
+	}
 
 	if (elems.ht_cap_elem && elems.ht_info_elem &&
 	    elems.wmm_param && conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE) {
@@ -2789,11 +2844,6 @@ static void ieee80211_rx_mgmt_beacon(struct net_device *dev,
 					       &bss_info);
 	}
 
-	if (elems.wmm_param && (ifsta->flags & IEEE80211_STA_WMM_ENABLED)) {
-		ieee80211_sta_wmm_params(dev, ifsta, elems.wmm_param,
-					 elems.wmm_param_len);
-	}
-
 	ieee80211_bss_info_change_notify(sdata, changed);
 }
 
diff --git a/net/mac80211/wext.c b/net/mac80211/wext.c
index 69aed16..76e1de1 100644
--- a/net/mac80211/wext.c
+++ b/net/mac80211/wext.c
@@ -236,6 +236,9 @@ static int ieee80211_ioctl_siwmode(struct net_device *dev,
 	case IW_MODE_ADHOC:
 		type = IEEE80211_IF_TYPE_IBSS;
 		break;
+	case IW_MODE_REPEAT:
+		type = IEEE80211_IF_TYPE_WDS;
+		break;
 	case IW_MODE_MONITOR:
 		type = IEEE80211_IF_TYPE_MNTR;
 		break;
@@ -980,6 +983,8 @@ static struct iw_statistics *ieee80211_get_wireless_stats(struct net_device *dev
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct sta_info *sta = NULL;
 
+	rcu_read_lock();
+
 	if (sdata->vif.type == IEEE80211_IF_TYPE_STA ||
 	    sdata->vif.type == IEEE80211_IF_TYPE_IBSS)
 		sta = sta_info_get(local, sdata->u.sta.bssid);
@@ -996,6 +1001,9 @@ static struct iw_statistics *ieee80211_get_wireless_stats(struct net_device *dev
 		wstats->qual.noise = sta->last_noise;
 		wstats->qual.updated = local->wstats_flags;
 	}
+
+	rcu_read_unlock();
+
 	return wstats;
 }