Re: [PATCH] vfio/type1: Fix unmap overflow off-by-one

[Cornelia Huck]

On Tue, 08 Jan 2019 09:40:06 -0700
Alex Williamson <alex.williamson@xxxxxxxxxx> wrote:

> The below referenced commit adds a test for integer overflow, but in
> doing so prevents the unmap ioctl from ever including the last page of
> the address space.  Subtract one to compare to the last address of the
> unmap to avoid the overflow and wrap-around.
> 
> Fixes: 71a7d3d78e3c ("vfio/type1: silence integer overflow warning")
> Link: https://bugzilla.redhat.com/show_bug.cgi?id=1662291
> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Reported-by: Pei Zhang <pezhang@xxxxxxxxxx>
> Debugged-by: Peter Xu <peterx@xxxxxxxxxx>
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
> ---
>  drivers/vfio/vfio_iommu_type1.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>