balloon: check the number of available pages in leak balloon

[pandora-kernel.git] / drivers / virtio / virtio_balloon.c

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 28153fb..2975c50 100644 (file)
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -142,6 +142,8 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num)
        /* We can only do one array worth at a time. */
        num = min(num, ARRAY_SIZE(vb->pfns));
 
+       /* We can't release more pages than taken */
+       num = min(num, (size_t)vb->num_pages);
        for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns++) {
                page = list_first_entry(&vb->pages, struct page, lru);
                list_del(&page->lru);