From: Florian Fainelli f.fainelli@gmail.com
[ Upstream commit 050569fc8384c8056bacefcc246bcb2dfe574936 ]
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@oracle.com Signed-off-by: Florian Fainelli f.fainelli@gmail.com Tested-by: Allen Pais allen.pais@oracle.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/dsa/master.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/dsa/master.c +++ b/net/dsa/master.c @@ -289,7 +289,8 @@ static void dsa_master_ndo_teardown(stru { 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; }