wifi: cfg80211: hold wiphy lock in pmsr work

Most code paths in cfg80211 already hold the wiphy lock,
mostly by virtue of being called from nl80211, so make
the pmsr cleanup worker also hold it, aligning the
locking promises between different parts of cfg80211.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/core.c

@@ -1145,8 +1145,6 @@ static void _cfg80211_unregister_wdev(struct wireless_dev *wdev,
 	ASSERT_RTNL();
 	lockdep_assert_held(&rdev->wiphy.mtx);
 
-	flush_work(&wdev->pmsr_free_wk);
-
 	nl80211_notify_iface(rdev, wdev, NL80211_CMD_DEL_INTERFACE);
 
 	wdev->registered = false;
@@ -1453,6 +1451,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 		wiphy_unlock(&rdev->wiphy);
 		/* since we just did cfg80211_leave() nothing to do there */
 		cancel_work_sync(&wdev->disconnect_wk);
+		cancel_work_sync(&wdev->pmsr_free_wk);
 		break;
 	case NETDEV_DOWN:
 		wiphy_lock(&rdev->wiphy);

net/wireless/pmsr.c

 /* SPDX-License-Identifier: GPL-2.0 */
 /*
- * Copyright (C) 2018 - 2021 Intel Corporation
+ * Copyright (C) 2018 - 2021, 2023 Intel Corporation
  */
 #include <net/cfg80211.h>
 #include "core.h"
@@ -623,9 +623,11 @@ void cfg80211_pmsr_free_wk(struct work_struct *work)
 	struct wireless_dev *wdev = container_of(work, struct wireless_dev,
 						 pmsr_free_wk);
 
+	wiphy_lock(wdev->wiphy);
 	wdev_lock(wdev);
 	cfg80211_pmsr_process_abort(wdev);
 	wdev_unlock(wdev);
+	wiphy_unlock(wdev->wiphy);
 }
 
 void cfg80211_pmsr_wdev_down(struct wireless_dev *wdev)