IB/mlx4: Verify port number in flow steering create flow

In procedure mlx4_ib_create_flow, passing an invalid port number
will cause an out-of-bounds array access. Data passed to this procedure
can come from user-space.  Therefore, need to validate port number
before proceeding onwards.

Note that we check against the number of physical ports declared at
the verbs (ib core) level; When bonding is active, the verbs level
sees one physical port, even though the low-level driver sees two ports.

Fixes: f77c0162 ("IB/mlx4: Add receive flow steering support")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Reviewed-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Reviewed-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx4/main.c

@@ -1704,6 +1704,9 @@ static struct ib_flow *mlx4_ib_create_flow(struct ib_qp *qp,
 	struct mlx4_dev *dev = (to_mdev(qp->device))->dev;
 	int is_bonded = mlx4_is_bonded(dev);
 
+	if (flow_attr->port < 1 || flow_attr->port > qp->device->phys_port_cnt)
+		return ERR_PTR(-EINVAL);
+
 	if ((flow_attr->flags & IB_FLOW_ATTR_FLAGS_DONT_TRAP) &&
 	    (flow_attr->type != IB_FLOW_ATTR_NORMAL))
 		return ERR_PTR(-EOPNOTSUPP);