virtio: console: Fix crash when port is unplugged and blocked for write

[sfrench/cifs-2.6.git] / drivers / char / virtio_console.c

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 8c99bf1b5e9fde218dab95f2091b807a7fbb4623..942a9826bd23ed64b83095fcdeb65ed059c9ce02 100644 (file)
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -529,6 +529,10 @@ static bool will_write_block(struct port *port)
 {
        bool ret;
 
+       if (!port->guest_connected) {
+               /* Port got hot-unplugged. Let's exit. */
+               return false;
+       }
        if (!port->host_connected)
                return true;
 
@@ -1099,6 +1103,13 @@ static int remove_port(struct port *port)
 {
        struct port_buffer *buf;
 
+       if (port->guest_connected) {
+               port->guest_connected = false;
+               port->host_connected = false;
+               wake_up_interruptible(&port->waitqueue);
+               send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
+       }
+
        spin_lock_irq(&port->portdev->ports_lock);
        list_del(&port->list);
        spin_unlock_irq(&port->portdev->ports_lock);
@@ -1120,9 +1131,6 @@ static int remove_port(struct port *port)
                hvc_remove(port->cons.hvc);
 #endif
        }
-       if (port->guest_connected)
-               send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
-
        sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
        device_destroy(pdrvdata.class, port->dev->devt);
        cdev_del(&port->cdev);