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

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

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..9e4631fade90 100644
--- a/net/mac802154/iface.c
+++ b/net/mac802154/iface.c
@@ -684,6 +684,10 @@ void ieee802154_if_remove(struct ieee802154_sub_if_data *sdata)
 	ASSERT_RTNL();
 
 	mutex_lock(&sdata->local->iflist_mtx);
+	if (list_empty(&sdata->local->interfaces)) {
+		mutex_unlock(&sdata->local->iflist_mtx);
+		return;
+	}
 	list_del_rcu(&sdata->list);
 	mutex_unlock(&sdata->local->iflist_mtx);