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Re: [Qemu-devel] [PATCH] vfio-pci: Fix BAR size overflow
From: |
Alex Williamson |
Subject: |
Re: [Qemu-devel] [PATCH] vfio-pci: Fix BAR size overflow |
Date: |
Tue, 6 Jan 2015 22:39:13 -0500 (EST) |
----- Original Message -----
> On 01/06/15 19:03, 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 an unsigned long. A similar issue is possible, though even more
> > unlikely, when mapping the region above an MSI-X table. The start of
> > the 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>
> > ---
> >
> > 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..03790a8 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;
> > + unsigned long size = bar->region.size;
>
> On a 32bit build, this does not fix the issue.
Very true. Thanks for the review,
Alex
> > 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;
> > + unsigned long start;
> >
> > start = HOST_PAGE_ALIGN(vdev->msix->table_offset +
> > (vdev->msix->entries *
> > PCI_MSIX_ENTRY_SIZE));
> >
> >
>
>