Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

5 files changed, 106 insertions, 11 deletions

diff --git a/kernel/net/wireless/core.h b/kernel/net/wireless/core.h
index a618b4b86..47ea169aa 100644
--- a/kernel/net/wireless/core.h
+++ b/kernel/net/wireless/core.h
@@ -72,6 +72,7 @@ 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;
@@ -397,6 +398,7 @@ void cfg80211_sme_disassoc(struct wireless_dev *wdev);
 void cfg80211_sme_deauth(struct wireless_dev *wdev);
 void cfg80211_sme_auth_timeout(struct wireless_dev *wdev);
 void cfg80211_sme_assoc_timeout(struct wireless_dev *wdev);
+void cfg80211_sme_abandon_assoc(struct wireless_dev *wdev);
 
 /* internal helpers */
 bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher);
diff --git a/kernel/net/wireless/mlme.c b/kernel/net/wireless/mlme.c
index fb44fa3bf..c0e02f72e 100644
--- a/kernel/net/wireless/mlme.c
+++ b/kernel/net/wireless/mlme.c
@@ -149,6 +149,18 @@ void cfg80211_assoc_timeout(struct net_device *dev, struct cfg80211_bss *bss)
 }
 EXPORT_SYMBOL(cfg80211_assoc_timeout);
 
+void cfg80211_abandon_assoc(struct net_device *dev, struct cfg80211_bss *bss)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	struct wiphy *wiphy = wdev->wiphy;
+
+	cfg80211_sme_abandon_assoc(wdev);
+
+	cfg80211_unhold_bss(bss_from_pub(bss));
+	cfg80211_put_bss(wiphy, bss);
+}
+EXPORT_SYMBOL(cfg80211_abandon_assoc);
+
 void cfg80211_tx_mlme_mgmt(struct net_device *dev, const u8 *buf, size_t len)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
diff --git a/kernel/net/wireless/nl80211.c b/kernel/net/wireless/nl80211.c
index 75b0d23ee..1f0de6d74 100644
--- a/kernel/net/wireless/nl80211.c
+++ b/kernel/net/wireless/nl80211.c
@@ -6628,7 +6628,7 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
 
 		params.n_counter_offsets_presp = len / sizeof(u16);
 		if (rdev->wiphy.max_num_csa_counters &&
-		    (params.n_counter_offsets_beacon >
+		    (params.n_counter_offsets_presp >
 		     rdev->wiphy.max_num_csa_counters))
 			return -EINVAL;
 
@@ -13161,20 +13161,24 @@ static int nl80211_netlink_notify(struct notifier_block * nb,
 	struct wireless_dev *wdev;
 	struct cfg80211_beacon_registration *reg, *tmp;
 
-	if (state != NETLINK_URELEASE)
+	if (state != NETLINK_URELEASE || notify->protocol != NETLINK_GENERIC)
 		return NOTIFY_DONE;
 
 	rcu_read_lock();
 
 	list_for_each_entry_rcu(rdev, &cfg80211_rdev_list, list) {
 		bool schedule_destroy_work = false;
-		bool schedule_scan_stop = false;
 		struct cfg80211_sched_scan_request *sched_scan_req =
 			rcu_dereference(rdev->sched_scan_req);
 
 		if (sched_scan_req && notify->portid &&
-		    sched_scan_req->owner_nlportid == notify->portid)
-			schedule_scan_stop = true;
+		    sched_scan_req->owner_nlportid == notify->portid) {
+			sched_scan_req->owner_nlportid = 0;
+
+			if (rdev->ops->sched_scan_stop &&
+			    rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_SCHED_SCAN)
+				schedule_work(&rdev->sched_scan_stop_wk);
+		}
 
 		list_for_each_entry_rcu(wdev, &rdev->wdev_list, list) {
 			cfg80211_mlme_unregister_socket(wdev, notify->portid);
@@ -13205,12 +13209,6 @@ static int nl80211_netlink_notify(struct notifier_block * nb,
 				spin_unlock(&rdev->destroy_list_lock);
 				schedule_work(&rdev->destroy_work);
 			}
-		} else if (schedule_scan_stop) {
-			sched_scan_req->owner_nlportid = 0;
-
-			if (rdev->ops->sched_scan_stop &&
-			    rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_SCHED_SCAN)
-				schedule_work(&rdev->sched_scan_stop_wk);
 		}
 	}
 
diff --git a/kernel/net/wireless/scan.c b/kernel/net/wireless/scan.c
index 14d5369eb..8dde12a11 100644
--- a/kernel/net/wireless/scan.c
+++ b/kernel/net/wireless/scan.c
@@ -56,6 +56,19 @@
  * 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)
@@ -136,6 +149,10 @@ 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;
 }
@@ -162,6 +179,40 @@ 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)
 {
@@ -687,6 +738,7 @@ 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))
@@ -710,6 +762,12 @@ 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)
@@ -738,6 +796,10 @@ 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;
 }
 
@@ -890,7 +952,14 @@ 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;
 	}
diff --git a/kernel/net/wireless/sme.c b/kernel/net/wireless/sme.c
index 8020b5b09..18b4a652c 100644
--- a/kernel/net/wireless/sme.c
+++ b/kernel/net/wireless/sme.c
@@ -39,6 +39,7 @@ struct cfg80211_conn {
 		CFG80211_CONN_ASSOCIATING,
 		CFG80211_CONN_ASSOC_FAILED,
 		CFG80211_CONN_DEAUTH,
+		CFG80211_CONN_ABANDON,
 		CFG80211_CONN_CONNECTED,
 	} state;
 	u8 bssid[ETH_ALEN], prev_bssid[ETH_ALEN];
@@ -204,6 +205,8 @@ static int cfg80211_conn_do_work(struct wireless_dev *wdev)
 		cfg80211_mlme_deauth(rdev, wdev->netdev, params->bssid,
 				     NULL, 0,
 				     WLAN_REASON_DEAUTH_LEAVING, false);
+		/* fall through */
+	case CFG80211_CONN_ABANDON:
 		/* free directly, disconnected event already sent */
 		cfg80211_sme_free(wdev);
 		return 0;
@@ -423,6 +426,17 @@ void cfg80211_sme_assoc_timeout(struct wireless_dev *wdev)
 	schedule_work(&rdev->conn_work);
 }
 
+void cfg80211_sme_abandon_assoc(struct wireless_dev *wdev)
+{
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
+
+	if (!wdev->conn)
+		return;
+
+	wdev->conn->state = CFG80211_CONN_ABANDON;
+	schedule_work(&rdev->conn_work);
+}
+
 static int cfg80211_sme_get_conn_ies(struct wireless_dev *wdev,
 				     const u8 *ies, size_t ies_len,
 				     const u8 **out_ies, size_t *out_ies_len)