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virt_wifi: fix deadlock on RTNL 

Fix a regression where everything in virt_wifi would just hang. This
happened due to overlapping changes between commit a05829a722
("cfg80211: avoid holding the RTNL when calling the driver") which
had originally needed to change the locking, but then I introduced
commit 2fe8ef1062 ("cfg80211: change netdev registration/unregistration
semantics") instead. virt_wifi somehow fell through the cracks when
I undid all the previous locking changes. Fix it now.

Fixes: a05829a722 ("cfg80211: avoid holding the RTNL when calling the driver")
Reported-by: syzbot+3d2d5e6cc3fb15c6a0fd@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20210127215941.2d6a97b09784.I4f1fac32f67045171be50931f44d77e150911bee@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
master
Johannes Berg 2021-01-27 21:59:42 +01:00
parent a05829a722
commit 38ec7c6b6b
1 changed files with 0 additions and 8 deletions
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8
drivers/net/wireless/virt_wifi.c
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@ -537,9 +537,7 @@ static int virt_wifi_newlink(struct net *src_net, struct net_device *dev,
dev->ieee80211_ptr->iftype = NL80211_IFTYPE_STATION;
dev->ieee80211_ptr->wiphy = common_wiphy;
wiphy_lock(common_wiphy);
err = register_netdevice(dev);
wiphy_unlock(common_wiphy);
if (err) {
dev_err(&priv->lowerdev->dev, "can't register_netdevice: %d\n",
err);
@ -562,9 +560,7 @@ static int virt_wifi_newlink(struct net *src_net, struct net_device *dev,
return 0;
unregister_netdev:
wiphy_lock(common_wiphy);
unregister_netdevice(dev);
wiphy_unlock(common_wiphy);
free_wireless_dev:
kfree(dev->ieee80211_ptr);
dev->ieee80211_ptr = NULL;
@ -590,9 +586,7 @@ static void virt_wifi_dellink(struct net_device *dev,
netdev_rx_handler_unregister(priv->lowerdev);
netdev_upper_dev_unlink(priv->lowerdev, dev);
wiphy_lock(common_wiphy);
unregister_netdevice_queue(dev, head);
wiphy_unlock(common_wiphy);
module_put(THIS_MODULE);
/* Deleting the wiphy is handled in the module destructor. */
@ -631,9 +625,7 @@ static int virt_wifi_event(struct notifier_block *this, unsigned long event,
upper_dev = priv->upperdev;
upper_dev->rtnl_link_ops->dellink(upper_dev, &list_kill);
wiphy_lock(common_wiphy);
unregister_netdevice_many(&list_kill);
wiphy_unlock(common_wiphy);
break;
}