net-sysfs: update the queue counts in the unregistration path

stable inclusion
from linux-4.19.226
commit 35cad2003b6447932cfe91f795090586306738e8

--------------------------------

[ Upstream commit d7dac083 ]

When updating Rx and Tx queue kobjects, the queue count should always be
updated to match the queue kobjects count. This was not done in the net
device unregistration path, fix it. Tracking all queue count updates
will allow in a following up patch to detect illegal updates.
Signed-off-by: NAntoine Tenart <atenart@kernel.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>
Signed-off-by: NLaibin Qiu <qiulaibin@huawei.com>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

net/core/net-sysfs.c

@@ -1616,6 +1616,9 @@ static void remove_queue_kobjects(struct net_device *dev)
 
 	net_rx_queue_update_kobjects(dev, real_rx, 0);
 	netdev_queue_update_kobjects(dev, real_tx, 0);
+
+	dev->real_num_rx_queues = 0;
+	dev->real_num_tx_queues = 0;
 #ifdef CONFIG_SYSFS
 	kset_unregister(dev->queues_kset);
 #endif