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-rw-r--r--net/mac80211/iface.c14
-rw-r--r--net/mac80211/main.c22
2 files changed, 35 insertions, 1 deletions
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 42e130a6aee9..c0539e78a34e 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -2284,6 +2284,20 @@ void ieee80211_remove_interfaces(struct ieee80211_local *local)
list_for_each_entry_safe(sdata, tmp, &unreg_list, list) {
bool netdev = sdata->dev;
+ /*
+ * Remove IP addresses explicitly, since the notifier will
+ * skip the callbacks if wdev->registered is false, since
+ * we can't acquire the wiphy_lock() again there if already
+ * inside this locked section.
+ */
+ sdata_lock(sdata);
+ sdata->vif.cfg.arp_addr_cnt = 0;
+ if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+ sdata->u.mgd.associated)
+ ieee80211_vif_cfg_change_notify(sdata,
+ BSS_CHANGED_ARP_FILTER);
+ sdata_unlock(sdata);
+
list_del(&sdata->list);
cfg80211_unregister_wdev(&sdata->wdev);
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index b6c089648441..f6860889fbdd 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -437,7 +437,7 @@ static int ieee80211_ifa_changed(struct notifier_block *nb,
if (!wdev)
return NOTIFY_DONE;
- if (wdev->wiphy != local->hw.wiphy)
+ if (wdev->wiphy != local->hw.wiphy || !wdev->registered)
return NOTIFY_DONE;
sdata = IEEE80211_DEV_TO_SUB_IF(ndev);
@@ -452,6 +452,25 @@ static int ieee80211_ifa_changed(struct notifier_block *nb,
return NOTIFY_DONE;
ifmgd = &sdata->u.mgd;
+
+ /*
+ * The nested here is needed to convince lockdep that this is
+ * all OK. Yes, we lock the wiphy mutex here while we already
+ * hold the notifier rwsem, that's the normal case. And yes,
+ * we also acquire the notifier rwsem again when unregistering
+ * a netdev while we already hold the wiphy mutex, so it does
+ * look like a typical ABBA deadlock.
+ *
+ * However, both of these things happen with the RTNL held
+ * already. Therefore, they can't actually happen, since the
+ * lock orders really are ABC and ACB, which is fine due to
+ * the RTNL (A).
+ *
+ * We still need to prevent recursion, which is accomplished
+ * by the !wdev->registered check above.
+ */
+ mutex_lock_nested(&local->hw.wiphy->mtx, 1);
+ __acquire(&local->hw.wiphy->mtx);
sdata_lock(sdata);
/* Copy the addresses to the vif config list */
@@ -470,6 +489,7 @@ static int ieee80211_ifa_changed(struct notifier_block *nb,
ieee80211_vif_cfg_change_notify(sdata, BSS_CHANGED_ARP_FILTER);
sdata_unlock(sdata);
+ wiphy_unlock(local->hw.wiphy);
return NOTIFY_OK;
}