From: "Michael S. Tsirkin" <mst@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Jason Wang <jasowang@redhat.com>,
virtualization@lists.linux-foundation.org,
David Hildenbrand <david@redhat.com>,
linux-mm@kvack.org
Subject: [PATCH] virtio_balloon: prevent pfn array overflow
Date: Thu, 6 Feb 2020 02:47:55 -0500 [thread overview]
Message-ID: <20200206074644.1177551-1-mst@redhat.com> (raw)
Make sure, at build time, that pfn array is big enough to hold a single
page. It happens to be true since the PAGE_SHIFT value at the moment is
20, which is 1M - exactly 256 4K balloon pages.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
drivers/virtio/virtio_balloon.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 8e400ece9273..2457c54b6185 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -158,6 +158,8 @@ static void set_page_pfns(struct virtio_balloon *vb,
{
unsigned int i;
+ BUILD_BUG_ON(VIRTIO_BALLOON_PAGES_PER_PAGE > VIRTIO_BALLOON_ARRAY_PFNS_MAX);
+
/*
* Set balloon pfns pointing at this page.
* Note that the first pfn points at start of the page.
--
MST
next reply other threads:[~2020-02-06 7:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-06 7:47 Michael S. Tsirkin [this message]
2020-02-06 8:29 ` [PATCH] virtio_balloon: prevent pfn array overflow David Hildenbrand
2020-02-07 3:37 ` Jason Wang
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