virtio: console: Ensure no memleaks in case of unused buffers

If unused data exists in in_vq, ensure we flush that first and then
detach unused buffers, which will ensure all buffers from the in_vq are
removed.

Also ensure we free the buffers after detaching them.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index a3f1f73bac3a..69d2e616dd0c 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -838,6 +838,8 @@ static const struct file_operations port_debugfs_ops = {
 /* Remove all port-specific data. */
 static int remove_port(struct port *port)
 {
+        struct port_buffer *buf;
+
         spin_lock_irq(&port->portdev->ports_lock);
         list_del(&port->list);
         spin_unlock_irq(&port->portdev->ports_lock);
@@ -851,14 +853,17 @@ static int remove_port(struct port *port)
         if (port->guest_connected)
                 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
 
-        while (port->in_vq->vq_ops->detach_unused_buf(port->in_vq))
-                ;
-
         sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
         device_destroy(pdrvdata.class, port->dev->devt);
         cdev_del(&port->cdev);
 
+        /* Remove unused data this port might have received. */
         discard_port_data(port);
+
+        /* Remove buffers we queued up for the Host to send us data in. */
+        while ((buf = port->in_vq->vq_ops->detach_unused_buf(port->in_vq)))
+                free_buf(buf);
+
         kfree(port->name);
 
         debugfs_remove(port->debugfs_file);