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virtio: pci-legacy: Validate queue pfn

[ Upstream commit 69599206ea ]

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" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <cdall@kernel.org>
Cc: Peter Maydel <peter.maydell@linaro.org>
Cc: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pull/10/head
Suzuki K Poulose 2018-07-18 10:18:45 +01:00 committed by Greg Kroah-Hartman
parent ab4bddc2d0
commit b7540b6235
1 changed files with 12 additions and 2 deletions

View File

@ -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);
}