net: ieee802154: fix nl802154 del llsec key

commit 37feaaf5ceb2245e474369312bb7b922ce7bce69 upstream.

This patch fixes a nullpointer dereference if NL802154_ATTR_SEC_KEY is
not set by the user. If this is the case nl802154 will return -EINVAL.

Reported-by: syzbot+ac5c11d2959a8b3c4806@syzkaller.appspotmail.com
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210221174321.14210-1-aahringo@redhat.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 16ef0d9f566e8436e55f0263c51585ae5ab751b9..6962ef1297c3b29ddf4cfe61747c2357b1e412c2 100644 (file)
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -1577,7 +1577,8 @@ static int nl802154_del_llsec_key(struct sk_buff *skb, struct genl_info *info)
        struct nlattr *attrs[NL802154_KEY_ATTR_MAX + 1];
        struct ieee802154_llsec_key_id id;
 
-       if (nla_parse_nested(attrs, NL802154_KEY_ATTR_MAX,
+       if (!info->attrs[NL802154_ATTR_SEC_KEY] ||
+           nla_parse_nested(attrs, NL802154_KEY_ATTR_MAX,
                             info->attrs[NL802154_ATTR_SEC_KEY],
                             nl802154_key_policy))
                return -EINVAL;