net/mlx4_core: Check port out-of-range before using in mlx4_slave_cap

The range check was performed after using the port number.

Reverse this to prevent a potential array overflow.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 7f71be0..ee6f4fe 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -485,15 +485,15 @@ static int mlx4_slave_cap(struct mlx4_dev *dev)
        dev->caps.num_mgms              = 0;
        dev->caps.num_amgms             = 0;
 
-       for (i = 1; i <= dev->caps.num_ports; ++i)
-               dev->caps.port_mask[i] = dev->caps.port_type[i];
-
        if (dev->caps.num_ports > MLX4_MAX_PORTS) {
                mlx4_err(dev, "HCA has %d ports, but we only support %d, "
                         "aborting.\n", dev->caps.num_ports, MLX4_MAX_PORTS);
                return -ENODEV;
        }
 
+       for (i = 1; i <= dev->caps.num_ports; ++i)
+               dev->caps.port_mask[i] = dev->caps.port_type[i];
+
        if (dev->caps.uar_page_size * (dev->caps.num_uars -
                                       dev->caps.reserved_uars) >
                                       pci_resource_len(dev->pdev, 2)) {