Reviewed-by: "Mitchell Augustin" <mitchell.augustin@xxxxxxxxxxxxx>
Tested-by: "Mitchell Augustin" <mitchell.augustin@xxxxxxxxxxxxx>
On Wed, Feb 5, 2025 at 5:18 PM Alex Williamson
<alex.williamson@xxxxxxxxxx> wrote:
>
> pin_user_pages_remote() can currently return zero for invalid args
> or zero nr_pages, neither of which should ever happen. However
> vaddr_get_pfns() indicates it should only ever return a positive
> value or -errno and there's a theoretical case where this can slip
> through and be unhandled by callers. Therefore convert zero to
> -EFAULT.
>
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
> ---
> drivers/vfio/vfio_iommu_type1.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 50ebc9593c9d..119cf886d8c0 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -564,6 +564,8 @@ static int vaddr_get_pfns(struct mm_struct *mm, unsigned long vaddr,
> if (ret > 0) {
> *pfn = page_to_pfn(pages[0]);
> goto done;
> + } else if (!ret) {
> + ret = -EFAULT;
> }
>
> vaddr = untagged_addr_remote(mm, vaddr);
> --
> 2.47.1
>
--
Mitchell Augustin
Software Engineer - Ubuntu Partner Engineering
