virtio: console: add locks around buffer removal in port unplug path

The removal functions act on the vqs, and the vq operations need to be
locked.

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

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 1b456fe9b87a..601962b1708b 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1513,18 +1513,22 @@ static void remove_port_data(struct port *port)
 {
         struct port_buffer *buf;
 
+        spin_lock_irq(&port->inbuf_lock);
         /* Remove unused data this port might have received. */
         discard_port_data(port);
 
-        reclaim_consumed_buffers(port);
-
         /* Remove buffers we queued up for the Host to send us data in. */
         while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
                 free_buf(buf, true);
+        spin_unlock_irq(&port->inbuf_lock);
+
+        spin_lock_irq(&port->outvq_lock);
+        reclaim_consumed_buffers(port);
 
         /* Free pending buffers from the out-queue. */
         while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
                 free_buf(buf, true);
+        spin_unlock_irq(&port->outvq_lock);
 }
 
 /*