From 65ba6008889cfa386f1067a3207272de9b2d9d09 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Wed, 5 Feb 2020 17:34:00 +0100 Subject: [PATCH] virtio-balloon: Fix memory leak when unloading while hinting is in progress commit 6c22dc61c76b7e7d355f1697ba0ecf26d1334ba6 upstream. When unloading the driver while hinting is in progress, we will not release the free page blocks back to MM, resulting in a memory leak. Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Wei Wang Cc: Liang Li Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20200205163402.42627-2-david@redhat.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman --- drivers/virtio/virtio_balloon.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 8e400ece9273..abef2306c899 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -968,6 +968,10 @@ static void remove_common(struct virtio_balloon *vb) leak_balloon(vb, vb->num_pages); update_balloon_size(vb); + /* There might be free pages that are being reported: release them. */ + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) + return_free_pages_to_mm(vb, ULONG_MAX); + /* Now we reset the device so we can clean up the queues. */ vb->vdev->config->reset(vb->vdev);