Re: [PATCH net] i40e: Fix VF MAC filter removal

[Michal Schmidt]

On Wed, Mar 13, 2024 at 2:56 PM Ivan Vecera <ivecera@xxxxxxxxxx> wrote:
> Commit 73d9629e1c8c ("i40e: Do not allow untrusted VF to remove
> administratively set MAC") fixed an issue where untrusted VF was
> allowed to remove its own MAC address although this was assigned
> administratively from PF. Unfortunately the introduced check
> is wrong because it causes that MAC filters for other MAC addresses
> including multi-cast ones are not removed.
>
> <snip>
>         if (ether_addr_equal(addr, vf->default_lan_addr.addr) &&
>             i40e_can_vf_change_mac(vf))
>                 was_unimac_deleted = true;
>         else
>                 continue;
>
>         if (i40e_del_mac_filter(vsi, al->list[i].addr)) {
>         ...
> </snip>
>
> The else path with `continue` effectively skips any MAC filter
> removal except one for primary MAC addr when VF is allowed to do so.
> Fix the check condition so the `continue` is only done for primary
> MAC address.
>
> Fixes: 73d9629e1c8c ("i40e: Do not allow untrusted VF to remove administratively set MAC")
> Signed-off-by: Ivan Vecera <ivecera@xxxxxxxxxx>
> ---
>  drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> index b34c71770887..10267a300770 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> @@ -3143,11 +3143,12 @@ static int i40e_vc_del_mac_addr_msg(struct i40e_vf *vf, u8 *msg)
>                 /* Allow to delete VF primary MAC only if it was not set
>                  * administratively by PF or if VF is trusted.
>                  */
> -               if (ether_addr_equal(addr, vf->default_lan_addr.addr) &&
> -                   i40e_can_vf_change_mac(vf))
> -                       was_unimac_deleted = true;
> -               else
> -                       continue;
> +               if (ether_addr_equal(addr, vf->default_lan_addr.addr)) {
> +                       if (i40e_can_vf_change_mac(vf))
> +                               was_unimac_deleted = true;
> +                       else
> +                               continue;
> +               }
>
>                 if (i40e_del_mac_filter(vsi, al->list[i].addr)) {
>                         ret = -EINVAL;
> --
> 2.43.0

Reviewed-by: Michal Schmidt <mschmidt@xxxxxxxxxx>