Messages in this thread | | | Subject | Re: [PATCH v3 01/20] virtio: mmio-v1: Validate queue PFN | From | Suzuki K Poulose <> | Date | Tue, 3 Jul 2018 09:04:01 +0100 |
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Hi Michael,
On 06/29/2018 06:42 PM, Michael S. Tsirkin wrote: > On Fri, Jun 29, 2018 at 12:15:21PM +0100, Suzuki K Poulose wrote: >> virtio-mmio with virtio-v1 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> >> --- >> Changes since v2: >> - Change errno to -E2BIG >> --- >> drivers/virtio/virtio_mmio.c | 18 ++++++++++++++++-- >> 1 file changed, 16 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c >> index 67763d3..82cedc8 100644 >> --- a/drivers/virtio/virtio_mmio.c >> +++ b/drivers/virtio/virtio_mmio.c >> @@ -397,9 +397,21 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, >> /* Activate the queue */ >> writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); >> if (vm_dev->version == 1) { >> + u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; >> + >> + /* >> + * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something >> + * that doesn't fit in 32bit, fail the setup rather than >> + * pretending to be successful. >> + */ >> + if (q_pfn >> 32) { >> + dev_err(&vdev->dev, "virtio-mmio: queue address too large\n"); > > How about: > "hypervisor bug: legacy virtio-mmio must not be used with more than 0x%llx Gigabytes of memory", > 0x1ULL << (32 - 30) << PAGE_SHIFT
nit : Do we need change "hypervisor" => "platform" ? Virtio is used by other tools (e.g, emulators) and not just virtual machines.
Suzuki
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