[PATCH v2] mac80211: Prevent unregistering of unregistered hw

[Ivo van Doorn <ivdoorn@gmail.com>]

At the moment it is possible to call ieee80211_unregister_hw()
for an unregistered hw structure. This will cause a big panic.
This patch will add a BUG_ON() line to warn about this situation.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>

---

diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c
index 577dbe3..e7a613d 100644
--- a/net/mac80211/ieee80211.c
+++ b/net/mac80211/ieee80211.c
@@ -4765,6 +4765,9 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw)
 	/* TODO: skb_queue should be empty here, no need to do anything? */
 
 	rtnl_lock();
+
+	BUG_ON(local->reg_state != IEEE80211_DEV_REGISTERED);
+
 	local->reg_state = IEEE80211_DEV_UNREGISTERED;
 	if (local->apdev)
 		ieee80211_if_del_mgmt(local);