virtio_balloon: prevent pfn array overflow
authorMichael S. Tsirkin <mst@redhat.com>
Thu, 6 Feb 2020 07:40:58 +0000 (02:40 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 24 Feb 2020 07:37:03 +0000 (08:37 +0100)
commit77912b69a989629c72922df67d27bcabdd80832a
treec68fd22bceb20173f86329f9055dbb18a7b9ffc9
parent9c80ae9650820f1f9578bc7289ddb6983a3b9651
virtio_balloon: prevent pfn array overflow

[ Upstream commit 6e9826e77249355c09db6ba41cd3f84e89f4b614 ]

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>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/virtio/virtio_balloon.c