net: ieee802154: stop dump llsec seclevels for monitors

[ Upstream commit 4c9b4f5 ]

This patch stops dumping llsec seclevels for monitors which we don't
support yet. Otherwise we will access llsec mib which isn't initialized
for monitors.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210405003054.256017-13-aahringo@redhat.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

net/ieee802154/nl802154.c

@@ -2031,6 +2031,11 @@ nl802154_dump_llsec_seclevel(struct sk_buff *skb, struct netlink_callback *cb)
 	if (err)
 		return err;
 
+	if (wpan_dev->iftype == NL802154_IFTYPE_MONITOR) {
+		err = skb->len;
+		goto out_err;
+	}
+
 	if (!wpan_dev->netdev) {
 		err = -EINVAL;
 		goto out_err;