nl80211: Stop scheduled scan if netlink client disappears

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>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index bacdf22..7029201 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -6214,6 +6214,9 @@
 	sched_scan_req->dev = dev;
 	sched_scan_req->wiphy = &rdev->wiphy;
 
+	if (info->attrs[NL80211_ATTR_SOCKET_OWNER])
+		sched_scan_req->owner_nlportid = info->snd_portid;
+
 	rcu_assign_pointer(rdev->sched_scan_req, sched_scan_req);
 
 	nl80211_send_sched_scan(rdev, dev,
@@ -12618,6 +12621,13 @@
 
 	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);
@@ -12648,6 +12658,12 @@
 				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);
 		}
 	}