A number of fixes:

* allow scanning when operating on radar channels in
    ETSI regdomains
  * accept deauth frames in IBSS - we have code to parse
    and handle them, but were dropping them early
  * fix an allocation failure path in hwsim
  * fix a failure path memory leak in nl80211 FTM code
  * fix RCU handling & locking in multi-BSSID parsing
  * reject malformed SSID in mac80211 (this shouldn't
    really be able to happen, but defense in depth)
  * avoid userspace buffer overrun in ancient wext code
    if SSID was too long
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Merge tag 'mac80211-for-davem-2019-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
A number of fixes:
 * allow scanning when operating on radar channels in
   ETSI regdomains
 * accept deauth frames in IBSS - we have code to parse
   and handle them, but were dropping them early
 * fix an allocation failure path in hwsim
 * fix a failure path memory leak in nl80211 FTM code
 * fix RCU handling & locking in multi-BSSID parsing
 * reject malformed SSID in mac80211 (this shouldn't
   really be able to happen, but defense in depth)
 * avoid userspace buffer overrun in ancient wext code
   if SSID was too long
====================

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

drivers/net/wireless/mac80211_hwsim.c

@@ -4026,7 +4026,7 @@ static int __init init_mac80211_hwsim(void)
 	err = dev_alloc_name(hwsim_mon, hwsim_mon->name);
 	if (err < 0) {
 		rtnl_unlock();
-		goto out_free_radios;
+		goto out_free_mon;
 	}
 
 	err = register_netdevice(hwsim_mon);

include/net/cfg80211.h

@@ -5549,6 +5549,14 @@ const struct ieee80211_reg_rule *freq_reg_info(struct wiphy *wiphy,
  */
 const char *reg_initiator_name(enum nl80211_reg_initiator initiator);
 
+/**
+ * regulatory_pre_cac_allowed - check if pre-CAC allowed in the current regdom
+ * @wiphy: wiphy for which pre-CAC capability is checked.
+ *
+ * Pre-CAC is allowed only in some regdomains (notable ETSI).
+ */
+bool regulatory_pre_cac_allowed(struct wiphy *wiphy);
+
 /**
  * DOC: Internal regulatory db functions
  *

net/mac80211/mlme.c

@@ -2633,7 +2633,8 @@ struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw,
 
 	rcu_read_lock();
 	ssid = ieee80211_bss_get_ie(cbss, WLAN_EID_SSID);
-	if (WARN_ON_ONCE(ssid == NULL))
+	if (WARN_ONCE(!ssid || ssid[1] > IEEE80211_MAX_SSID_LEN,
+		      "invalid SSID element (len=%d)", ssid ? ssid[1] : -1))
 		ssid_len = 0;
 	else
 		ssid_len = ssid[1];
@@ -5233,7 +5234,7 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 
 	rcu_read_lock();
 	ssidie = ieee80211_bss_get_ie(req->bss, WLAN_EID_SSID);
-	if (!ssidie) {
+	if (!ssidie || ssidie[1] > sizeof(assoc_data->ssid)) {
 		rcu_read_unlock();
 		kfree(assoc_data);
 		return -EINVAL;

net/mac80211/rx.c

@@ -3467,9 +3467,18 @@ ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
 	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
 		/* process for all: mesh, mlme, ibss */
 		break;
+	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
+		if (is_multicast_ether_addr(mgmt->da) &&
+		    !is_broadcast_ether_addr(mgmt->da))
+			return RX_DROP_MONITOR;
+
+		/* process only for station/IBSS */
+		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
+		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
+			return RX_DROP_MONITOR;
+		break;
 	case cpu_to_le16(IEEE80211_STYPE_ASSOC_RESP):
 	case cpu_to_le16(IEEE80211_STYPE_REASSOC_RESP):
-	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
 	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
 		if (is_multicast_ether_addr(mgmt->da) &&
 		    !is_broadcast_ether_addr(mgmt->da))

net/mac80211/scan.c

@@ -520,10 +520,33 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 	return 0;
 }
 
+static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_sub_if_data *sdata_iter;
+
+	if (!ieee80211_is_radar_required(local))
+		return true;
+
+	if (!regulatory_pre_cac_allowed(local->hw.wiphy))
+		return false;
+
+	mutex_lock(&local->iflist_mtx);
+	list_for_each_entry(sdata_iter, &local->interfaces, list) {
+		if (sdata_iter->wdev.cac_started) {
+			mutex_unlock(&local->iflist_mtx);
+			return false;
+		}
+	}
+	mutex_unlock(&local->iflist_mtx);
+
+	return true;
+}
+
 static bool ieee80211_can_scan(struct ieee80211_local *local,
 			       struct ieee80211_sub_if_data *sdata)
 {
-	if (ieee80211_is_radar_required(local))
+	if (!__ieee80211_can_leave_ch(sdata))
 		return false;
 
 	if (!list_empty(&local->roc_list))
@@ -630,7 +653,10 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 
 	lockdep_assert_held(&local->mtx);
 
-	if (local->scan_req || ieee80211_is_radar_required(local))
+	if (local->scan_req)
+		return -EBUSY;
+
+	if (!__ieee80211_can_leave_ch(sdata))
 		return -EBUSY;
 
 	if (!ieee80211_can_scan(local, sdata)) {

net/wireless/nl80211.c

@@ -13682,7 +13682,7 @@ static int nl80211_get_ftm_responder_stats(struct sk_buff *skb,
 	hdr = nl80211hdr_put(msg, info->snd_portid, info->snd_seq, 0,
 			     NL80211_CMD_GET_FTM_RESPONDER_STATS);
 	if (!hdr)
-		return -ENOBUFS;
+		goto nla_put_failure;
 
 	if (nla_put_u32(msg, NL80211_ATTR_IFINDEX, dev->ifindex))
 		goto nla_put_failure;

net/wireless/reg.c

@@ -3883,6 +3883,7 @@ bool regulatory_pre_cac_allowed(struct wiphy *wiphy)
 
 	return pre_cac_allowed;
 }
+EXPORT_SYMBOL(regulatory_pre_cac_allowed);
 
 void regulatory_propagate_dfs_state(struct wiphy *wiphy,
 				    struct cfg80211_chan_def *chandef,

net/wireless/reg.h

@@ -155,14 +155,6 @@ bool regulatory_indoor_allowed(void);
  */
 #define REG_PRE_CAC_EXPIRY_GRACE_MS 2000
 
-/**
- * regulatory_pre_cac_allowed - if pre-CAC allowed in the current dfs domain
- * @wiphy: wiphy for which pre-CAC capability is checked.
-
- * Pre-CAC is allowed only in ETSI domain.
- */
-bool regulatory_pre_cac_allowed(struct wiphy *wiphy);
-
 /**
  * regulatory_propagate_dfs_state - Propagate DFS channel state to other wiphys
  * @wiphy - wiphy on which radar is detected and the event will be propagated

net/wireless/scan.c

@@ -1703,8 +1703,7 @@ cfg80211_parse_mbssid_frame_data(struct wiphy *wiphy,
 static void
 cfg80211_update_notlisted_nontrans(struct wiphy *wiphy,
 				   struct cfg80211_bss *nontrans_bss,
-				   struct ieee80211_mgmt *mgmt, size_t len,
-				   gfp_t gfp)
+				   struct ieee80211_mgmt *mgmt, size_t len)
 {
 	u8 *ie, *new_ie, *pos;
 	const u8 *nontrans_ssid, *trans_ssid, *mbssid;
@@ -1715,6 +1714,8 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy,
 	const struct cfg80211_bss_ies *old;
 	u8 cpy_len;
 
+	lockdep_assert_held(&wiphy_to_rdev(wiphy)->bss_lock);
+
 	ie = mgmt->u.probe_resp.variable;
 
 	new_ie_len = ielen;
@@ -1731,23 +1732,22 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy,
 	if (!mbssid || mbssid < trans_ssid)
 		return;
 	new_ie_len -= mbssid[1];
-	rcu_read_lock();
+
 	nontrans_ssid = ieee80211_bss_get_ie(nontrans_bss, WLAN_EID_SSID);
-	if (!nontrans_ssid) {
-		rcu_read_unlock();
+	if (!nontrans_ssid)
 		return;
-	}
+
 	new_ie_len += nontrans_ssid[1];
-	rcu_read_unlock();
 
 	/* generate new ie for nontrans BSS
 	 * 1. replace SSID with nontrans BSS' SSID
 	 * 2. skip MBSSID IE
 	 */
-	new_ie = kzalloc(new_ie_len, gfp);
+	new_ie = kzalloc(new_ie_len, GFP_ATOMIC);
 	if (!new_ie)
 		return;
-	new_ies = kzalloc(sizeof(*new_ies) + new_ie_len, gfp);
+
+	new_ies = kzalloc(sizeof(*new_ies) + new_ie_len, GFP_ATOMIC);
 	if (!new_ies)
 		goto out_free;
 
@@ -1901,6 +1901,8 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
 	cfg80211_parse_mbssid_frame_data(wiphy, data, mgmt, len,
 					 &non_tx_data, gfp);
 
+	spin_lock_bh(&wiphy_to_rdev(wiphy)->bss_lock);
+
 	/* check if the res has other nontransmitting bss which is not
 	 * in MBSSID IE
 	 */
@@ -1915,8 +1917,9 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
 		ies2 = rcu_access_pointer(tmp_bss->ies);
 		if (ies2->tsf < ies1->tsf)
 			cfg80211_update_notlisted_nontrans(wiphy, tmp_bss,
-							   mgmt, len, gfp);
+							   mgmt, len);
 	}
+	spin_unlock_bh(&wiphy_to_rdev(wiphy)->bss_lock);
 
 	return res;
 }

net/wireless/wext-sme.c

@@ -202,6 +202,7 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev,
 			       struct iw_point *data, char *ssid)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	int ret = 0;
 
 	/* call only for station! */
 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
@@ -219,6 +220,9 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev,
 		if (ie) {
 			data->flags = 1;
 			data->length = ie[1];
+			if (data->length > IW_ESSID_MAX_SIZE)
+				ret = -EINVAL;
+			else
 				memcpy(ssid, ie + 2, data->length);
 		}
 		rcu_read_unlock();
@@ -229,7 +233,7 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev,
 	}
 	wdev_unlock(wdev);
 
-	return 0;
+	return ret;
 }
 
 int cfg80211_mgd_wext_siwap(struct net_device *dev,