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 <[email protected]> Signed-off-by: Florian Fainelli <[email protected]>
Tested-by: Allen Pais <[email protected]> Thank you Florain.
--- net/dsa/master.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/dsa/master.c b/net/dsa/master.c index b5c535af63a3..a621367c6e8c 100644 --- a/net/dsa/master.c +++ b/net/dsa/master.c @@ -289,7 +289,8 @@ static void dsa_master_ndo_teardown(struct net_device *dev) { struct dsa_port *cpu_dp = dev->dsa_ptr;- dev->netdev_ops = cpu_dp->orig_ndo_ops;+ if (cpu_dp->orig_ndo_ops) + dev->netdev_ops = cpu_dp->orig_ndo_ops; cpu_dp->orig_ndo_ops = NULL; }
