cfg80211: add missing device list locking

When calling into the wext code from the NETDEV_UP notifier, we need to hold the devlist_mtx mutex as the wext code ends up calling into channel checks.

---
 net/wireless/core.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -710,6 +710,7 @@ static int cfg80211_netdev_notifier_call
 	case NETDEV_UP:
 #ifdef CONFIG_WIRELESS_EXT
 		cfg80211_lock_rdev(rdev);
+		mutex_lock(&rdev->devlist_mtx);
 		wdev_lock(wdev);
 		switch (wdev->iftype) {
 		case NL80211_IFTYPE_ADHOC:

@@ -722,6 +723,7 @@ static int cfg80211_netdev_notifier_call
 			break;
 		}
 		wdev_unlock(wdev);
+		mutex_unlock(&rdev->devlist_mtx);
 		cfg80211_unlock_rdev(rdev);
 #endif
 		break;

Thanks for fixing this. I wasn't able to reproduce the warning after one suspend/resume cycle, but I'll test this patch a bit more before I send my Tested-by tag.

Kalle Valo

I have been testing with patch for a day now and no warnings anymore.

Kalle Valo