On Wed, Oct 21, 2020 at 01:07:12AM -0500, Lijun Pan wrote:
> Jakub Kicinski brought up a concern in ibmvnic_set_mac().
> ibmvnic_set_mac() does this:
>
> ether_addr_copy(adapter->mac_addr, addr->sa_data);
> if (adapter->state != VNIC_PROBED)
> rc = __ibmvnic_set_mac(netdev, addr->sa_data);
>
> So if state == VNIC_PROBED, the user can assign an invalid address to
> adapter->mac_addr, and ibmvnic_set_mac() will still return 0.
>
> The fix is to add the handling for "adapter->state == VNIC_PROBED" case,
> which saves the old mac address back to adapter->mac_addr, and
> returns an error code.
>
> Fixes: 62740e97881c ("net/ibmvnic: Update MAC address settings after adapter
> reset")
> Cc: Jakub Kicinski <k...@kernel.org>
> Signed-off-by: Lijun Pan <l...@linux.ibm.com>
> ---
> v2: change the subject from v1's
> "ibmvnic: no need to update adapter->mac_addr before it completes"
> handle adapter->state==VNIC_PROBED case in else statement.
>
> drivers/net/ethernet/ibm/ibmvnic.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/ibm/ibmvnic.c
> b/drivers/net/ethernet/ibm/ibmvnic.c
> index 4dd3625a4fbc..0d78e1e3d44c 100644
> --- a/drivers/net/ethernet/ibm/ibmvnic.c
> +++ b/drivers/net/ethernet/ibm/ibmvnic.c
> @@ -1829,8 +1829,12 @@ static int ibmvnic_set_mac(struct net_device *netdev,
> void *p)
>
> rc = 0;
> ether_addr_copy(adapter->mac_addr, addr->sa_data);
> - if (adapter->state != VNIC_PROBED)
> + if (adapter->state != VNIC_PROBED) {
> rc = __ibmvnic_set_mac(netdev, addr->sa_data);
> + } else {
> + ether_addr_copy(adapter->mac_addr, netdev->dev_addr);
> + rc = -EIO;
Why suddenly you want to change the behavior for case when ibmvnic_set_mac
is called for VNIC_PROBED state?
I went through the previous discussion and I have a feeling that Jakub
meant to simply call the is_valid_ether_addr() on addr->sa_data before the
first ether_addr_copy and then act accordingly based on the validity of
user supplied mac addr.
And instead of yet another write to adapter->mac_addr that you're
introducing you could just move the first ether_addr_copy (if
addr->sa_data is valid) onto the if (adapter->state != VNIC_PROBED)
condition. Right?
> + }
>
> return rc;
> }
> --
> 2.23.0
>
