From: Johannes Berg Date: Thu, 30 Jul 2009 12:04:01 +0000 (+0200) Subject: cfg80211: fix NETDEV_UNREGISTER notifier X-Git-Tag: v2.6.32-rc1~703^2~459^2~68 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=e40cbdac0629402a4cb0c3bca0cc19ab7a00e00d;p=~shefty%2Frdma-dev.git cfg80211: fix NETDEV_UNREGISTER notifier It's possible to get the NETDEV_UNREGISTER callback multiple times (see net/core/dev.c:netdev_wait_allrefs) and this will completely mess up our cleanup code. To avoid that, clean up only when the interface is still on the wiphy interface list from which it's removed on the first NETDEV_UNREGISTER call. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- diff --git a/net/wireless/core.c b/net/wireless/core.c index 755cdf1643c..1493285b6a4 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -725,15 +725,22 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb, break; case NETDEV_UNREGISTER: mutex_lock(&rdev->devlist_mtx); + /* + * It is possible to get NETDEV_UNREGISTER + * multiple times. To detect that, check + * that the interface is still on the list + * of registered interfaces, and only then + * remove and clean it up. + */ if (!list_empty(&wdev->list)) { sysfs_remove_link(&dev->dev.kobj, "phy80211"); list_del_init(&wdev->list); - } - mutex_unlock(&rdev->devlist_mtx); - mutex_destroy(&wdev->mtx); + mutex_destroy(&wdev->mtx); #ifdef CONFIG_WIRELESS_EXT - kfree(wdev->wext.keys); + kfree(wdev->wext.keys); #endif + } + mutex_unlock(&rdev->devlist_mtx); break; case NETDEV_PRE_UP: if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)))