net: ieee802154: stop dump llsec devkeys for monitors

stable inclusion
from stable-5.10.32
commit 07714229e0e2e9ad8ea19582ad3c41578ccb8c4c
bugzilla: 51796

--------------------------------

[ Upstream commit 080d1a57 ]

This patch stops dumping llsec devkeys for monitors which we don't support
yet. Otherwise we will access llsec mib which isn't initialized for
monitors.
Signed-off-by: NAlexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210405003054.256017-10-aahringo@redhat.comSigned-off-by: NStefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/ieee802154/nl802154.c

@@ -1858,6 +1858,11 @@ nl802154_dump_llsec_devkey(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;