* [PATCH] virtio_balloon: prevent pfn array overflow
@ 2020-02-06 7:47 Michael S. Tsirkin
2020-02-06 8:29 ` David Hildenbrand
2020-02-07 3:37 ` Jason Wang
0 siblings, 2 replies; 3+ messages in thread
From: Michael S. Tsirkin @ 2020-02-06 7:47 UTC (permalink / raw)
To: linux-kernel; +Cc: Jason Wang, virtualization, David Hildenbrand, linux-mm
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
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] virtio_balloon: prevent pfn array overflow
2020-02-06 7:47 [PATCH] virtio_balloon: prevent pfn array overflow Michael S. Tsirkin
@ 2020-02-06 8:29 ` David Hildenbrand
2020-02-07 3:37 ` Jason Wang
1 sibling, 0 replies; 3+ messages in thread
From: David Hildenbrand @ 2020-02-06 8:29 UTC (permalink / raw)
To: Michael S. Tsirkin, linux-kernel; +Cc: Jason Wang, virtualization, linux-mm
On 06.02.20 08:47, Michael S. Tsirkin wrote:
> 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.
>
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] virtio_balloon: prevent pfn array overflow
2020-02-06 7:47 [PATCH] virtio_balloon: prevent pfn array overflow Michael S. Tsirkin
2020-02-06 8:29 ` David Hildenbrand
@ 2020-02-07 3:37 ` Jason Wang
1 sibling, 0 replies; 3+ messages in thread
From: Jason Wang @ 2020-02-07 3:37 UTC (permalink / raw)
To: Michael S. Tsirkin, linux-kernel
Cc: virtualization, David Hildenbrand, linux-mm
On 2020/2/6 下午3:47, Michael S. Tsirkin wrote:
> 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.
Acked-by: Jason Wang <jasowang@redhat.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-02-06 8:29 ` David Hildenbrand
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