Re: [PATCH net 3/4] ice: don't remove netdev->dev_addr from uc sync list

On 8/9/21 1:14 PM, Tony Nguyen wrote:

From: Brett Creeley <redacted>

In some circumstances, such as with bridging, it's possible that the
stack will add the device's own MAC address to its unicast address list.

If, later, the stack deletes this address, the driver will receive a
request to remove this address.

The driver stores its current MAC address as part of the VSI MAC filter
list instead of separately. So, this causes a problem when the device's
MAC address is deleted unexpectedly, which results in traffic failure in
some cases.

The following configuration steps will reproduce the previously
mentioned problem:

quoted

ip link set eth0 up
ip link add dev br0 type bridge
ip link set br0 up
ip addr flush dev eth0
ip link set eth0 master br0
echo 1 > /sys/class/net/br0/bridge/vlan_filtering
modprobe -r veth
modprobe -r bridge
ip addr add 192.168.1.100/24 dev eth0

The following ping command fails due to the netdev->dev_addr being
deleted when removing the bridge module.

quoted

ping <link partner>

Fix this by making sure to not delete the netdev->dev_addr during MAC
address sync. After fixing this issue it was noticed that the
netdev_warn() in .set_mac was overly verbose, so make it at
netdev_dbg().

Also, there is a possibility of a race condition between .set_mac and
.set_rx_mode. Fix this by calling netif_addr_lock_bh() and
netif_addr_unlock_bh() on the device's netdev when the netdev->dev_addr
is going to be updated in .set_mac.

Fixes: e94d44786693 ("ice: Implement filter sync, NDO operations and bump version")
Signed-off-by: Brett Creeley <redacted>
Tested-by: Liang Li <redacted>
Tested-by: Gurucharan G <redacted>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Tested-by: Jonathan Toppins <redacted>