vhost-user: Fix userfaultfd leak

'fd' received from the vhost side is never freed.
Also, everything (including 'postcopy_listen' state) should be
cleaned up on vhost cleanup.

Fixes: 46343570c06e ("vhost+postcopy: Wire up POSTCOPY_END notify")
Fixes: f82c11165ffa ("vhost+postcopy: Register shared ufd with postcopy")
Cc: qemu-stable@nongnu.org
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Message-Id: <20181008160536.6332-3-i.maximets@samsung.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit c4f753859ae6da1aeb93cad19c586fea1925e269)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index c442daa562c3085aefcc79b78e8f5bc463e9da95..e09bed0e4a716f083f2224512fbd1399a321c247 100644 (file)
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1280,6 +1280,7 @@ static int vhost_user_postcopy_end(struct vhost_dev *dev, Error **errp)
         return ret;
     }
     postcopy_unregister_shared_ufd(&u->postcopy_fd);
+    close(u->postcopy_fd.fd);
     u->postcopy_fd.handler = NULL;
 
     trace_vhost_user_postcopy_end_exit();
@@ -1419,6 +1420,12 @@ static int vhost_user_backend_cleanup(struct vhost_dev *dev)
         postcopy_remove_notifier(&u->postcopy_notifier);
         u->postcopy_notifier.notify = NULL;
     }
+    u->postcopy_listen = false;
+    if (u->postcopy_fd.handler) {
+        postcopy_unregister_shared_ufd(&u->postcopy_fd);
+        close(u->postcopy_fd.fd);
+        u->postcopy_fd.handler = NULL;
+    }
     if (u->slave_fd >= 0) {
         qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
         close(u->slave_fd);