i40e: define proper net_device::neigh_priv_len

Out of bound read reported by KASan.

i40iw_net_event() reads unconditionally 16 bytes from
neigh->primary_key while the memory allocated for
"neighbour" struct is evaluated in neigh_alloc() as

  tbl->entry_size + dev->neigh_priv_len

where "dev" is a net_device.

But the driver does not setup dev->neigh_priv_len and
we read beyond the neigh entry allocated memory,
so the patch in the next mail fixes this.

Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index fbb21ac..5824d74 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -12339,6 +12339,9 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
        ether_addr_copy(netdev->dev_addr, mac_addr);
        ether_addr_copy(netdev->perm_addr, mac_addr);
 
+       /* i40iw_net_event() reads 16 bytes from neigh->primary_key */
+       netdev->neigh_priv_len = sizeof(u32) * 4;
+
        netdev->priv_flags |= IFF_UNICAST_FLT;
        netdev->priv_flags |= IFF_SUPP_NOFCS;
        /* Setup netdev TC information */