[PATCH v2] cfg80211: Acquire wiphy mutex on regulatory work

[Luca Coelho <luca@coelho.fi>]

From: Ilan Peer <ilan.peer@intel.com>

The function cfg80211_reg_can_beacon_relax() expects wiphy
mutex to be held when it is being called. However, when
reg_leave_invalid_chans() is called the mutex is not held.
Fix it by acquiring the lock before calling the function.

Fixes: a05829a7222e ("cfg80211: avoid holding the RTNL when calling the driver")
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
---

In v2:
    * Remove duplicate Fixes tag.

net/wireless/reg.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index df87c7f3a049..6f6da1cedd80 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -2338,6 +2338,7 @@ static bool reg_wdev_chan_valid(struct wiphy *wiphy, struct wireless_dev *wdev)
 	struct cfg80211_chan_def chandef = {};
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 	enum nl80211_iftype iftype;
+	bool ret;
 
 	wdev_lock(wdev);
 	iftype = wdev->iftype;
@@ -2387,7 +2388,11 @@ static bool reg_wdev_chan_valid(struct wiphy *wiphy, struct wireless_dev *wdev)
 	case NL80211_IFTYPE_AP:
 	case NL80211_IFTYPE_P2P_GO:
 	case NL80211_IFTYPE_ADHOC:
-		return cfg80211_reg_can_beacon_relax(wiphy, &chandef, iftype);
+		wiphy_lock(wiphy);
+		ret = cfg80211_reg_can_beacon_relax(wiphy, &chandef, iftype);
+		wiphy_unlock(wiphy);
+
+		return ret;
 	case NL80211_IFTYPE_STATION:
 	case NL80211_IFTYPE_P2P_CLIENT:
 		return cfg80211_chandef_usable(wiphy, &chandef,
@@ -2409,7 +2414,6 @@ static void reg_leave_invalid_chans(struct wiphy *wiphy)
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 
 	ASSERT_RTNL();
-
 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list)
 		if (!reg_wdev_chan_valid(wiphy, wdev))
 			cfg80211_leave(rdev, wdev);
-- 
2.33.1