Re: [PATCH net] net: dsa: Do not leave DSA master with NULL netdev_ops

[David Miller]

From: Florian Fainelli <f.fainelli@xxxxxxxxx>
Date: Mon,  4 May 2020 13:18:06 -0700

> When ndo_get_phys_port_name() for the CPU port was added we introduced
> an early check for when the DSA master network device in
> dsa_master_ndo_setup() already implements ndo_get_phys_port_name(). When
> we perform the teardown operation in dsa_master_ndo_teardown() we would
> not be checking that cpu_dp->orig_ndo_ops was successfully allocated and
> non-NULL initialized.
> 
> With network device drivers such as virtio_net, this leads to a NPD as
> soon as the DSA switch hanging off of it gets torn down because we are
> now assigning the virtio_net device's netdev_ops a NULL pointer.
> 
> Fixes: da7b9e9b00d4 ("net: dsa: Add ndo_get_phys_port_name() for CPU port")
> Reported-by: Allen Pais <allen.pais@xxxxxxxxxx>
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>

Applied and queued up for -stable, thanks Florian.