This is a note to let you know that I've just added the patch titled
mac80211: close AP_VLAN interfaces before unregistering all
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mac80211-close-ap_vlan-interfaces-before-unregistering-all.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4c8a9d4bfaf7dbc7d2168494904d79d22cc01db7 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@xxxxxxxxx>
Date: Fri, 24 May 2013 01:06:09 +0200
Subject: mac80211: close AP_VLAN interfaces before unregistering all
From: Johannes Berg <johannes.berg@xxxxxxxxx>
commit 4c8a9d4bfaf7dbc7d2168494904d79d22cc01db7 upstream.
Since Eric's commit efe117ab8 ("Speedup ieee80211_remove_interfaces")
there's a bug in mac80211 when it unregisters with AP_VLAN interfaces
up. If the AP_VLAN interface was registered after the AP it belongs
to (which is the typical case) and then we get into this code path,
unregister_netdevice_many() will crash because it isn't prepared to
deal with interfaces being closed in the middle of it. Exactly this
happens though, because we iterate the list, find the AP master this
AP_VLAN belongs to and dev_close() the dependent VLANs. After this,
unregister_netdevice_many() won't pick up the fact that the AP_VLAN
is already down and will do it again, causing a crash.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mac80211/iface.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1405,6 +1405,15 @@ void ieee80211_recalc_idle(struct ieee80
{
u32 chg;
+ /*
+ * Close all AP_VLAN interfaces first, as otherwise they
+ * might be closed while the AP interface they belong to
+ * is closed, causing unregister_netdevice_many() to crash.
+ */
+ list_for_each_entry(sdata, &local->interfaces, list)
+ if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+ dev_close(sdata->dev);
+
mutex_lock(&local->iflist_mtx);
chg = __ieee80211_recalc_idle(local);
mutex_unlock(&local->iflist_mtx);
Patches currently in stable-queue which might be from johannes.berg@xxxxxxxxx are
queue-3.4/mac80211-close-ap_vlan-interfaces-before-unregistering-all.patch
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