A few more bugfixes:

* limit # of scan results stored in memory - this is a long-standing bug
    Jouni and I only noticed while discussing other things in Santa Fe
  * revert AP_LINK_PS patch that was causing issues (Felix)
  * various A-MSDU/A-MPDU fixes for TXQ code (Felix)
  * interoperability workaround for peers with broken VHT capabilities
    (Filip Matusiak)
  * add bitrate definition for a VHT MCS that's supposed to be invalid
    but gets used by some hardware anyway (Thomas Pedersen)
  * beacon timer fix in hwsim (Benjamin Beichler)
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABCgAGBQJYLrKJAAoJEGt7eEactAAdshYP/Rwi/k9WZ0RKQIA1QA0fnmwv
 TbUUvPHQ4LA39Czs0JwOPDIbter7TBzFXV5EK0y39jGm8St4a/oHuN072kzBYvob
 YbBzM0YKV2uQCAjH3AjWjS3RPOlTzfUqSRWgEqtgUTC5VZrpNfhd2r0q+jfwpQ7s
 +qUsdwqvVJMZKfOEngIXzNXdI95N1d8tpGwzkUqDbOJ+7amdriiJKyTsKEOMqREA
 0Mdhu6roEcMDVO+xt5ZkilmpLZOUEHAzaWkwm7d6VToWi7k3pwMiEZ4fthvHZHEZ
 6K2bn1UMLdKAExRcQBE3wrmn5jFfUbts1mhmoN1drHocI12epcgw5I4ZjEbfpqMB
 IBkOM+2hbSdUVfE4KVH6iubqiJwtHB8YSTdKFmMO4jPx7UshPF7YCny6XWC+EqQm
 ktjyG/lhlXJ0HaOKC/MAwd/KSzfH0eJWGNBDV5s/FIWiqu2oWn+ZIX7vGTpp4K1Z
 Rery/ZUiJGzVITNG1ka+GXq2tUvDXfkMApr+jFH4G6zioWovxB6+4uyMEeclvC5q
 zjgYEpZhbn2wQUNEJ8btDDgXkyDGh3UPjy93fO8fMEvv8d9CCOKTQkIUpjPp6jbZ
 EoLCTW0NNjnAmQRiUFF3vO2O7e3ZTJ4hyNEVkc7mJ2X3DllXRSelTIFSfZVHpb2k
 P+gY7uC0cAPZ4s6q8GSb
 =q2mI
 -----END PGP SIGNATURE-----

Merge tag 'mac80211-for-davem-2016-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
A few more bugfixes:
 * limit # of scan results stored in memory - this is a long-standing bug
   Jouni and I only noticed while discussing other things in Santa Fe
 * revert AP_LINK_PS patch that was causing issues (Felix)
 * various A-MSDU/A-MPDU fixes for TXQ code (Felix)
 * interoperability workaround for peers with broken VHT capabilities
   (Filip Matusiak)
 * add bitrate definition for a VHT MCS that's supposed to be invalid
   but gets used by some hardware anyway (Thomas Pedersen)
 * beacon timer fix in hwsim (Benjamin Beichler)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wireless/mac80211_hwsim.c

@@ -826,7 +826,7 @@ static void mac80211_hwsim_set_tsf(struct ieee80211_hw *hw,
 		data->bcn_delta = do_div(delta, bcn_int);
 	} else {
 		data->tsf_offset -= delta;
-		data->bcn_delta = -do_div(delta, bcn_int);
+		data->bcn_delta = -(s64)do_div(delta, bcn_int);
 	}
 }
 

net/mac80211/sta_info.c

@@ -688,7 +688,7 @@ static void __sta_info_recalc_tim(struct sta_info *sta, bool ignore_pending)
 	}
 
 	/* No need to do anything if the driver does all */
-	if (!local->ops->set_tim)
+	if (ieee80211_hw_check(&local->hw, AP_LINK_PS))
 		return;
 
 	if (sta->dead)

net/mac80211/tx.c

@@ -1501,7 +1501,6 @@ static bool ieee80211_queue_skb(struct ieee80211_local *local,
 				struct sta_info *sta,
 				struct sk_buff *skb)
 {
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct fq *fq = &local->fq;
 	struct ieee80211_vif *vif;
 	struct txq_info *txqi;
@@ -1526,8 +1525,6 @@ static bool ieee80211_queue_skb(struct ieee80211_local *local,
 	if (!txqi)
 		return false;
 
-	info->control.vif = vif;
-
 	spin_lock_bh(&fq->lock);
 	ieee80211_txq_enqueue(local, txqi, skb);
 	spin_unlock_bh(&fq->lock);
@@ -3213,7 +3210,6 @@ static void ieee80211_xmit_fast_finish(struct ieee80211_sub_if_data *sdata,
 
 	if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
 		tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
-		*ieee80211_get_qos_ctl(hdr) = tid;
 		hdr->seq_ctrl = ieee80211_tx_next_seq(sta, tid);
 	} else {
 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
@@ -3338,6 +3334,11 @@ static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
 		      (tid_tx ? IEEE80211_TX_CTL_AMPDU : 0);
 	info->control.flags = IEEE80211_TX_CTRL_FAST_XMIT;
 
+	if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
+		tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
+		*ieee80211_get_qos_ctl(hdr) = tid;
+	}
+
 	__skb_queue_head_init(&tx.skbs);
 
 	tx.flags = IEEE80211_TX_UNICAST;
@@ -3426,6 +3427,11 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
 		goto begin;
 	}
 
+	if (test_bit(IEEE80211_TXQ_AMPDU, &txqi->flags))
+		info->flags |= IEEE80211_TX_CTL_AMPDU;
+	else
+		info->flags &= ~IEEE80211_TX_CTL_AMPDU;
+
 	if (info->control.flags & IEEE80211_TX_CTRL_FAST_XMIT) {
 		struct sta_info *sta = container_of(txq->sta, struct sta_info,
 						    sta);

net/mac80211/vht.c

@@ -270,6 +270,22 @@ ieee80211_vht_cap_ie_to_sta_vht_cap(struct ieee80211_sub_if_data *sdata,
 		vht_cap->vht_mcs.tx_mcs_map |= cpu_to_le16(peer_tx << i * 2);
 	}
 
+	/*
+	 * This is a workaround for VHT-enabled STAs which break the spec
+	 * and have the VHT-MCS Rx map filled in with value 3 for all eight
+	 * spacial streams, an example is AR9462.
+	 *
+	 * As per spec, in section 22.1.1 Introduction to the VHT PHY
+	 * A VHT STA shall support at least single spactial stream VHT-MCSs
+	 * 0 to 7 (transmit and receive) in all supported channel widths.
+	 */
+	if (vht_cap->vht_mcs.rx_mcs_map == cpu_to_le16(0xFFFF)) {
+		vht_cap->vht_supported = false;
+		sdata_info(sdata, "Ignoring VHT IE from %pM due to invalid rx_mcs_map\n",
+			   sta->addr);
+		return;
+	}
+
 	/* finally set up the bandwidth */
 	switch (vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
 	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:

net/wireless/core.h

@@ -71,6 +71,7 @@ struct cfg80211_registered_device {
 	struct list_head bss_list;
 	struct rb_root bss_tree;
 	u32 bss_generation;
+	u32 bss_entries;
 	struct cfg80211_scan_request *scan_req; /* protected by RTNL */
 	struct sk_buff *scan_msg;
 	struct cfg80211_sched_scan_request __rcu *sched_scan_req;

net/wireless/scan.c

@@ -57,6 +57,19 @@
  * also linked into the probe response struct.
  */
 
+/*
+ * Limit the number of BSS entries stored in mac80211. Each one is
+ * a bit over 4k at most, so this limits to roughly 4-5M of memory.
+ * If somebody wants to really attack this though, they'd likely
+ * use small beacons, and only one type of frame, limiting each of
+ * the entries to a much smaller size (in order to generate more
+ * entries in total, so overhead is bigger.)
+ */
+static int bss_entries_limit = 1000;
+module_param(bss_entries_limit, int, 0644);
+MODULE_PARM_DESC(bss_entries_limit,
+                 "limit to number of scan BSS entries (per wiphy, default 1000)");
+
 #define IEEE80211_SCAN_RESULT_EXPIRE	(30 * HZ)
 
 static void bss_free(struct cfg80211_internal_bss *bss)
@@ -137,6 +150,10 @@ static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
 
 	list_del_init(&bss->list);
 	rb_erase(&bss->rbn, &rdev->bss_tree);
+	rdev->bss_entries--;
+	WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list),
+		  "rdev bss entries[%d]/list[empty:%d] corruption\n",
+		  rdev->bss_entries, list_empty(&rdev->bss_list));
 	bss_ref_put(rdev, bss);
 	return true;
 }
@@ -163,6 +180,40 @@ static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
 		rdev->bss_generation++;
 }
 
+static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev)
+{
+	struct cfg80211_internal_bss *bss, *oldest = NULL;
+	bool ret;
+
+	lockdep_assert_held(&rdev->bss_lock);
+
+	list_for_each_entry(bss, &rdev->bss_list, list) {
+		if (atomic_read(&bss->hold))
+			continue;
+
+		if (!list_empty(&bss->hidden_list) &&
+		    !bss->pub.hidden_beacon_bss)
+			continue;
+
+		if (oldest && time_before(oldest->ts, bss->ts))
+			continue;
+		oldest = bss;
+	}
+
+	if (WARN_ON(!oldest))
+		return false;
+
+	/*
+	 * The callers make sure to increase rdev->bss_generation if anything
+	 * gets removed (and a new entry added), so there's no need to also do
+	 * it here.
+	 */
+
+	ret = __cfg80211_unlink_bss(rdev, oldest);
+	WARN_ON(!ret);
+	return ret;
+}
+
 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
 			   bool send_message)
 {
@@ -689,6 +740,7 @@ static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 	const u8 *ie;
 	int i, ssidlen;
 	u8 fold = 0;
+	u32 n_entries = 0;
 
 	ies = rcu_access_pointer(new->pub.beacon_ies);
 	if (WARN_ON(!ies))
@@ -712,6 +764,12 @@ static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 	/* This is the bad part ... */
 
 	list_for_each_entry(bss, &rdev->bss_list, list) {
+		/*
+		 * we're iterating all the entries anyway, so take the
+		 * opportunity to validate the list length accounting
+		 */
+		n_entries++;
+
 		if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 			continue;
 		if (bss->pub.channel != new->pub.channel)
@@ -740,6 +798,10 @@ static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 				   new->pub.beacon_ies);
 	}
 
+	WARN_ONCE(n_entries != rdev->bss_entries,
+		  "rdev bss entries[%d]/list[len:%d] corruption\n",
+		  rdev->bss_entries, n_entries);
+
 	return true;
 }
 
@@ -894,7 +956,14 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 			}
 		}
 
+		if (rdev->bss_entries >= bss_entries_limit &&
+		    !cfg80211_bss_expire_oldest(rdev)) {
+			kfree(new);
+			goto drop;
+		}
+
 		list_add_tail(&new->list, &rdev->bss_list);
+		rdev->bss_entries++;
 		rb_insert_bss(rdev, new);
 		found = new;
 	}

net/wireless/util.c

@@ -1158,7 +1158,8 @@ static u32 cfg80211_calculate_bitrate_vht(struct rate_info *rate)
 		   58500000,
 		   65000000,
 		   78000000,
-		   0,
+		/* not in the spec, but some devices use this: */
+		   86500000,
 		},
 		{  13500000,
 		   27000000,