[PATCH AUTOSEL 5.4 04/39] net: ieee802154: fix nl802154 del llsec devkey

[Sasha Levin]

From: Alexander Aring <aahringo@xxxxxxxxxx>

[ Upstream commit 27c746869e1a135dffc2f2a80715bb7aa00445b4 ]

This patch fixes a nullpointer dereference if NL802154_ATTR_SEC_DEVKEY is
not set by the user. If this is the case nl802154 will return -EINVAL.

Reported-by: syzbot+368672e0da240db53b5f@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210221174321.14210-4-aahringo@xxxxxxxxxx
Signed-off-by: Stefan Schmidt <stefan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/ieee802154/nl802154.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 43003108be95..c398f1ac74b8 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -1932,7 +1932,8 @@ static int nl802154_del_llsec_devkey(struct sk_buff *skb, struct genl_info *info
 	struct ieee802154_llsec_device_key key;
 	__le64 extended_addr;
 
-	if (nla_parse_nested_deprecated(attrs, NL802154_DEVKEY_ATTR_MAX, info->attrs[NL802154_ATTR_SEC_DEVKEY], nl802154_devkey_policy, info->extack))
+	if (!info->attrs[NL802154_ATTR_SEC_DEVKEY] ||
+	    nla_parse_nested_deprecated(attrs, NL802154_DEVKEY_ATTR_MAX, info->attrs[NL802154_ATTR_SEC_DEVKEY], nl802154_devkey_policy, info->extack))
 		return -EINVAL;
 
 	if (!attrs[NL802154_DEVKEY_ATTR_EXTENDED_ADDR])
-- 
2.30.2