From e40cbdac0629402a4cb0c3bca0cc19ab7a00e00d Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 30 Jul 2009 14:04:01 +0200 Subject: [PATCH] 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 --- net/wireless/core.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/net/wireless/core.c b/net/wireless/core.c index 755cdf1643c9..1493285b6a4d 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))) -- 2.20.1