From 69599206ea9a3f8f2e94d46580579cbf9d08ad6c Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Wed, 18 Jul 2018 10:18:45 +0100 Subject: virtio: pci-legacy: Validate queue pfn Legacy PCI over virtio uses a 32bit PFN for the queue. If the queue pfn is too large to fit in 32bits, which we could hit on arm64 systems with 52bit physical addresses (even with 64K page size), we simply miss out a proper link to the other side of the queue. Add a check to validate the PFN, rather than silently breaking the devices. Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Marc Zyngier Cc: Christoffer Dall Cc: Peter Maydel Cc: Jean-Philippe Brucker Signed-off-by: Suzuki K Poulose Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_pci_legacy.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c index 2780886e8ba3..de062fb201bc 100644 --- a/drivers/virtio/virtio_pci_legacy.c +++ b/drivers/virtio/virtio_pci_legacy.c @@ -122,6 +122,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, struct virtqueue *vq; u16 num; int err; + u64 q_pfn; /* Select the queue we're interested in */ iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); @@ -141,9 +142,17 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, if (!vq) return ERR_PTR(-ENOMEM); + q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT; + if (q_pfn >> 32) { + dev_err(&vp_dev->pci_dev->dev, + "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", + 0x1ULL << (32 + PAGE_SHIFT - 30)); + err = -E2BIG; + goto out_del_vq; + } + /* activate the queue */ - iowrite32(virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT, - vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); + iowrite32(q_pfn, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY; @@ -160,6 +169,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, out_deactivate: iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); +out_del_vq: vring_del_virtqueue(vq); return ERR_PTR(err); } -- cgit v1.2.3-59-g8ed1b