[PATCH v7 13/28] iommufd/viommu: Add IOMMUFD_CMD_HW_QUEUE_ALLOC ioctl

[Jason Gunthorpe]

On Thu, Jun 26, 2025 at 12:34:44PM -0700, Nicolin Chen wrote:
> +static struct iommufd_access *
> +iommufd_hw_queue_alloc_phys(struct iommu_hw_queue_alloc *cmd,
> +			    struct iommufd_viommu *viommu, phys_addr_t *base_pa)
> +{
> +	struct iommufd_access *access;
> +	struct page **pages;
> +	int max_npages, i;

These types are not int..

> +	u64 offset;
> +	int rc;
> +
> +	offset =
> +		cmd->nesting_parent_iova - PAGE_ALIGN(cmd->nesting_parent_iova);

This is a u64

> +	max_npages = DIV_ROUND_UP(offset + cmd->length, PAGE_SIZE);

Length is a u64

It should be

/* DIV_ROUND_UP(offset + cmd->length, PAGE_SIZE) */
if (check_add_overflow(offset, cmd->length, &length))
   return -ERANGE;
if (check_add_overflow(length, PAGE_SIZE-1, &length))
   return -ERANGE;
if (length > SIZE_MAX)
   return -ERANGE;
max_npages = length / PAGE_SIZE;

And then max_npages and i should be size_t.

Otherwise it looks OK

Reviewed-by: Jason Gunthorpe <jgg at nvidia.com>

Jason