dst/connector: Disallow unpliviged users to configure dst

(cherry picked from commit dbbb3431228784612848a1ec6061c78b4b708b5c)
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/dst/dcore.c

@@ -854,6 +854,11 @@ static void cn_dst_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 	struct dst_node *n = NULL, *tmp;
 	unsigned int hash;
 
+	if (!cap_raised(nsp->eff_cap, CAP_SYS_ADMIN)) {
+		err = -EPERM;
+		goto out;
+	}
+
 	if (msg->len < sizeof(struct dst_ctl)) {
 		err = -EBADMSG;
 		goto out;