From 9992a5244e2c1fed6b8a92447686cc902d8f2202 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 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: 074bd7f3d238 ("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 --- 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 2457c54b6185f..6d063eeaa08ab 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -970,6 +970,10 @@ 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); -- 2.39.5