net: ieee802154: forbid monitor for add llsec dev

stable inclusion
from stable-5.10.32
commit 813b13155d14c4cdcaf8085c3d2f0ff9cec60f53
bugzilla: 51796

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

[ Upstream commit 5303f956 ]

This patch forbids to add llsec dev for monitor interfaces 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/20210405003054.256017-8-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

@@ -1768,6 +1768,9 @@ static int nl802154_add_llsec_dev(struct sk_buff *skb, struct genl_info *info)
 	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
 	struct ieee802154_llsec_device dev_desc;
 
+	if (wpan_dev->iftype == NL802154_IFTYPE_MONITOR)
+		return -EOPNOTSUPP;
+
 	if (ieee802154_llsec_parse_device(info->attrs[NL802154_ATTR_SEC_DEVICE],
 					  &dev_desc) < 0)
 		return -EINVAL;