From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:39204 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751426AbZG3MEf (ORCPT ); Thu, 30 Jul 2009 08:04:35 -0400 Subject: [PATCH] cfg80211: fix NETDEV_UNREGISTER notifier From: Johannes Berg To: John Linville Cc: linux-wireless Content-Type: text/plain Date: Thu, 30 Jul 2009 14:04:01 +0200 Message-Id: <1248955441.29062.37.camel@johannes.local> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: 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 --- net/wireless/core.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) --- wireless-testing.orig/net/wireless/core.c 2009-07-30 13:41:26.000000000 +0200 +++ wireless-testing/net/wireless/core.c 2009-07-30 13:52:59.000000000 +0200 @@ -725,15 +725,22 @@ static int cfg80211_netdev_notifier_call 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)))