xen-netfront: properly destroy queues when removing device
xennet_remove() freed the queues before freeing the netdevice which
results in a use-after-free when free_netdev() tries to delete the
napi instances that have already been freed.
Fix this by fully destroy the queues (which includes deleting the napi
instances) before freeing the netdevice.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 3f45afd4..e031c94 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1698,6 +1698,7 @@
if (netif_running(info->netdev))
napi_disable(&queue->napi);
+ del_timer_sync(&queue->rx_refill_timer);
netif_napi_del(&queue->napi);
}
@@ -2102,9 +2103,6 @@
static int xennet_remove(struct xenbus_device *dev)
{
struct netfront_info *info = dev_get_drvdata(&dev->dev);
- unsigned int num_queues = info->netdev->real_num_tx_queues;
- struct netfront_queue *queue = NULL;
- unsigned int i = 0;
dev_dbg(&dev->dev, "%s\n", dev->nodename);
@@ -2112,16 +2110,7 @@
unregister_netdev(info->netdev);
- for (i = 0; i < num_queues; ++i) {
- queue = &info->queues[i];
- del_timer_sync(&queue->rx_refill_timer);
- }
-
- if (num_queues) {
- kfree(info->queues);
- info->queues = NULL;
- }
-
+ xennet_destroy_queues(info);
xennet_free_netdev(info->netdev);
return 0;