Re: [syzbot] [net?] KASAN: slab-use-after-free Read in sock_def_readable (2)

[Hillf Danton]

#syz test: upstream 651690480a96

--- a/net/atm/lec.c
+++ b/net/atm/lec.c
@@ -474,6 +474,7 @@ static void lec_atm_close(struct atm_vcc
 
 	priv->lecd = NULL;
 	/* Do something needful? */
+	synchronize_rcu();
 
 	netif_stop_queue(dev);
 	lec_arp_destroy(priv);
--