Re: [PATCH net] i40e: Do not allow untrusted VF to remove administratively set MAC

[Simon Horman]

On Wed, Jan 31, 2024 at 02:17:14PM +0100, Ivan Vecera wrote:
> Currently when PF administratively sets VF's MAC address and the VF
> is put down (VF tries to delete all MACs) then the MAC is removed
> from MAC filters and primary VF MAC is zeroed.
> 
> Do not allow untrusted VF to remove primary MAC when it was set
> administratively by PF.
> 
> Reproducer:
> 1) Create VF
> 2) Set VF interface up
> 3) Administratively set the VF's MAC
> 4) Put VF interface down
> 
> [root@host ~]# echo 1 > /sys/class/net/enp2s0f0/device/sriov_numvfs
> [root@host ~]# ip link set enp2s0f0v0 up
> [root@host ~]# ip link set enp2s0f0 vf 0 mac fe:6c:b5:da:c7:7d
> [root@host ~]# ip link show enp2s0f0
> 23: enp2s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
>     link/ether 3c:ec:ef:b7:dd:04 brd ff:ff:ff:ff:ff:ff
>     vf 0     link/ether fe:6c:b5:da:c7:7d brd ff:ff:ff:ff:ff:ff, spoof checking on, link-state auto, trust off
> [root@host ~]# ip link set enp2s0f0v0 down
> [root@host ~]# ip link show enp2s0f0
> 23: enp2s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
>     link/ether 3c:ec:ef:b7:dd:04 brd ff:ff:ff:ff:ff:ff
>     vf 0     link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff, spoof checking on, link-state auto, trust off
> 
> Fixes: 700bbf6c1f9e ("i40e: allow VF to remove any MAC filter")
> Fixes: ceb29474bbbc ("i40e: Add support for VF to specify its primary MAC address")
> Signed-off-by: Ivan Vecera <ivecera@xxxxxxxxxx>

Thanks Ivan,

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>