Re: [syzbot] Re: [syzbot] [wpan?] [usb?] BUG: corrupted list in ieee802154_if_remove

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@xxxxxxxxxxxxxxx.

***

Subject: Re: [syzbot] [wpan?] [usb?] BUG: corrupted list in ieee802154_if_remove
Author: lizhi.xu@xxxxxxxxxxxxx

net device has been unregistered, since the rcu grace period it must be run before ieee802154_if_remove

#syz test

diff --git a/net/mac802154/iface.c b/net/mac802154/iface.c
index c0e2da5072be..6f24f1760969 100644
--- a/net/mac802154/iface.c
+++ b/net/mac802154/iface.c
@@ -684,7 +684,8 @@ void ieee802154_if_remove(struct ieee802154_sub_if_data *sdata)
 	ASSERT_RTNL();
 
 	mutex_lock(&sdata->local->iflist_mtx);
-	list_del_rcu(&sdata->list);
+	if (!list_empty(&sdata->local->interfaces))
+		list_del_rcu(&sdata->list);
 	mutex_unlock(&sdata->local->iflist_mtx);
 
 	synchronize_rcu();