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Re: [Qemu-devel] [PATCH v2] vfio-pci: Fix BAR size overflow
From: |
Alexey Kardashevskiy |
Subject: |
Re: [Qemu-devel] [PATCH v2] vfio-pci: Fix BAR size overflow |
Date: |
Thu, 08 Jan 2015 23:32:20 +1100 |
User-agent: |
Mozilla/5.0 (X11; Linux i686 on x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 |
On 01/08/2015 04:23 AM, Alex Williamson wrote:
> We use an unsigned int when working with the PCI BAR size, which can
> obviously overflow if the BAR is 4GB or larger. This needs to change
> to a fixed length uint64_t. A similar issue is possible, though even
> more unlikely, when mapping the region above an MSI-X table. The
> start of the MSI-X vector table must be below 4GB, but the end, and
> therefore the start of the next mapping region, could still land at
> 4GB.
>
> Suggested-by: Nishank Trivedi <address@hidden>
> Signed-off-by: Alex Williamson <address@hidden>
Tested-by: Alexey Kardashevskiy <address@hidden>
Helped me with 16GB BARs.
> ---
>
> v2: s/unsigned long/uint64_t/, duh
>
> hw/vfio/pci.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index b4e73d1..b6703c7 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -2301,7 +2301,7 @@ static void vfio_unmap_bar(VFIOPCIDevice *vdev, int nr)
> static void vfio_map_bar(VFIOPCIDevice *vdev, int nr)
> {
> VFIOBAR *bar = &vdev->bars[nr];
> - unsigned size = bar->region.size;
> + uint64_t size = bar->region.size;
> char name[64];
> uint32_t pci_bar;
> uint8_t type;
> @@ -2351,7 +2351,7 @@ static void vfio_map_bar(VFIOPCIDevice *vdev, int nr)
> }
>
> if (vdev->msix && vdev->msix->table_bar == nr) {
> - unsigned start;
> + uint64_t start;
>
> start = HOST_PAGE_ALIGN(vdev->msix->table_offset +
> (vdev->msix->entries * PCI_MSIX_ENTRY_SIZE));
>
>
--
Alexey