diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 996b68b48a87..4e4179209982 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3621,6 +3621,9 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info)
 	if (err)
 		return err;
 
+	if (key.idx < 0)
+		return -EINVAL;
+
 	if (info->attrs[NL80211_ATTR_MAC])
 		mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);