[PATCH AUTOSEL 5.4 01/29] net: ieee802154: fix null deref in parse dev addr

[Sasha Levin <sashal@kernel.org>]

From: Dan Robertson <dan@dlrobertson.com>

[ Upstream commit 9fdd04918a452980631ecc499317881c1d120b70 ]

Fix a logic error that could result in a null deref if the user sets
the mode incorrectly for the given addr type.

Signed-off-by: Dan Robertson <dan@dlrobertson.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210423040214.15438-2-dan@dlrobertson.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/ieee802154/nl802154.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 328bb9f5342e..b2ba1d2556f1 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -1314,19 +1314,20 @@ ieee802154_llsec_parse_dev_addr(struct nlattr *nla,
 	if (!nla || nla_parse_nested_deprecated(attrs, NL802154_DEV_ADDR_ATTR_MAX, nla, nl802154_dev_addr_policy, NULL))
 		return -EINVAL;
 
-	if (!attrs[NL802154_DEV_ADDR_ATTR_PAN_ID] ||
-	    !attrs[NL802154_DEV_ADDR_ATTR_MODE] ||
-	    !(attrs[NL802154_DEV_ADDR_ATTR_SHORT] ||
-	      attrs[NL802154_DEV_ADDR_ATTR_EXTENDED]))
+	if (!attrs[NL802154_DEV_ADDR_ATTR_PAN_ID] || !attrs[NL802154_DEV_ADDR_ATTR_MODE])
 		return -EINVAL;
 
 	addr->pan_id = nla_get_le16(attrs[NL802154_DEV_ADDR_ATTR_PAN_ID]);
 	addr->mode = nla_get_u32(attrs[NL802154_DEV_ADDR_ATTR_MODE]);
 	switch (addr->mode) {
 	case NL802154_DEV_ADDR_SHORT:
+		if (!attrs[NL802154_DEV_ADDR_ATTR_SHORT])
+			return -EINVAL;
 		addr->short_addr = nla_get_le16(attrs[NL802154_DEV_ADDR_ATTR_SHORT]);
 		break;
 	case NL802154_DEV_ADDR_EXTENDED:
+		if (!attrs[NL802154_DEV_ADDR_ATTR_EXTENDED])
+			return -EINVAL;
 		addr->extended_addr = nla_get_le64(attrs[NL802154_DEV_ADDR_ATTR_EXTENDED]);
 		break;
 	default:
-- 
2.30.2