[Qemu-devel] [PULL 4/7] vhost-user: Fix userfaultfd leak

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: Ilya Maximets <i.maximets@samsung.com>

'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>
---
 hw/virtio/vhost-user.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index b041343632..ed47d645d9 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1291,6 +1291,7 @@ 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();
@@ -1430,6 +1431,12 @@ 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);
-- 
2.19.0