BACKPORT: nl80211: Stop scheduled scan if netlink client disappears

(cherry pick from commit 93a1e86ce10e4898f9ca9cd09d659a8a7780ee5e)

An attribute NL80211_ATTR_SOCKET_OWNER can be set by the scan initiator.
If present, the attribute will cause the scan to be stopped if the client
dies.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Bug: 25561044
Change-Id: Ibe4a555b29b64b6df1b9ed4cdcd0f05a69416d14

3 files changed, 34 insertions, 0 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 0603f5982..0fc9d7531 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -344,6 +344,20 @@ static void cfg80211_destroy_iface_wk(struct work_struct *work)
 	rtnl_unlock();
 }
 
+static void cfg80211_sched_scan_stop_wk(struct work_struct *work)
+{
+	struct cfg80211_registered_device *rdev;
+
+	rdev = container_of(work, struct cfg80211_registered_device,
+			   sched_scan_stop_wk);
+
+	rtnl_lock();
+
+	__cfg80211_stop_sched_scan(rdev, false);
+
+	rtnl_unlock();
+}
+
 /* exported functions */
 
 struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
@@ -410,6 +424,7 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
 	INIT_LIST_HEAD(&rdev->destroy_list);
 	spin_lock_init(&rdev->destroy_list_lock);
 	INIT_WORK(&rdev->destroy_work, cfg80211_destroy_iface_wk);
+	INIT_WORK(&rdev->sched_scan_stop_wk, cfg80211_sched_scan_stop_wk);
 
 #ifdef CONFIG_CFG80211_DEFAULT_PS
 	rdev->wiphy.flags |= WIPHY_FLAG_PS_ON_BY_DEFAULT;
@@ -780,6 +795,7 @@ void wiphy_unregister(struct wiphy *wiphy)
 	flush_work(&rdev->event_work);
 	cancel_delayed_work_sync(&rdev->dfs_update_channels_wk);
 	flush_work(&rdev->destroy_work);
+	flush_work(&rdev->sched_scan_stop_wk);
 
 	if (rdev->wowlan && rdev->ops->set_wakeup)
 		rdev_set_wakeup(rdev, false);
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 9363ac0a4..20db2b1ec 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -94,6 +94,8 @@ struct cfg80211_registered_device {
 	struct list_head destroy_list;
 	struct work_struct destroy_work;
 
+	struct work_struct sched_scan_stop_wk;
+
 	/* must be last because of the way we do wiphy_priv(),
 	 * and it should at least be aligned to NETDEV_ALIGN */
 	struct wiphy wiphy __aligned(NETDEV_ALIGN);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 7cd5224d5..713d9439b 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5600,6 +5600,9 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
 
 	err = rdev_sched_scan_start(rdev, dev, request);
 	if (!err) {
+		if (info->attrs[NL80211_ATTR_IFACE_SOCKET_OWNER])
+			request->owner_nlportid = info->snd_portid;
+
 		rdev->sched_scan_req = request;
 		nl80211_send_sched_scan(rdev, dev,
 					NL80211_CMD_START_SCHED_SCAN);
@@ -10907,6 +10910,13 @@ static int nl80211_netlink_notify(struct notifier_block * nb,
 
 	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;
 
 		list_for_each_entry_rcu(wdev, &rdev->wdev_list, list) {
 			cfg80211_mlme_unregister_socket(wdev, notify->portid);
@@ -10937,6 +10947,12 @@ 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);
 		}
 	}