diff mbox

cfg80211: fix NETDEV_UNREGISTER notifier

Message ID 1248955441.29062.37.camel@johannes.local (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Johannes Berg July 30, 2009, 12:04 p.m. UTC
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 <johannes@sipsolutions.net>
---
 net/wireless/core.c |   15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)



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diff mbox

Patch

--- 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)))