net: ieee802154: fix nl802154 add llsec key

commit 20d5fe2d7103f5c43ad11a3d6d259e9d61165c35 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+ce4e062c2d51977ddc50@syzkaller.appspotmail.com
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210221174321.14210-3-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 bae42ad9b7a42e092b506ecf3b97aa734ed53fb0..489eb256ee2a3c1f4c71b035d6a9d033d0e363b3 100644 (file)
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -1577,7 +1577,8 @@ static int nl802154_add_llsec_key(struct sk_buff *skb, struct genl_info *info)
        struct ieee802154_llsec_key_id id = { };
        u32 commands[NL802154_CMD_FRAME_NR_IDS / 32] = { };
 
-       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;