2022-10-17 12:48:13

by Niklas Schnelle

Subject: [PATCH v7 4/6] iommu/s390: Fix incorrect aperture check

The domain->geometry.aperture_end specifies the last valid address treat
it as such when checking if a DMA address is valid.

Reviewed-by: Pierre Morel <[email protected]>
Reviewed-by: Matthew Rosato <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
---
v3->v4:
- Make check robust against overflow (Jason)

drivers/iommu/s390-iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index c4203a37faa4..fa8cb97bfc88 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -213,7 +213,7 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
int rc = 0;

if (dma_addr < s390_domain->domain.geometry.aperture_start ||
- dma_addr + size > s390_domain->domain.geometry.aperture_end)
+ (dma_addr + size - 1) > s390_domain->domain.geometry.aperture_end)
return -EINVAL;

nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
--
2.34.1

2022-10-24 18:37:57

by Jason Gunthorpe

Subject: Re: [PATCH v7 4/6] iommu/s390: Fix incorrect aperture check

On Mon, Oct 17, 2022 at 02:45:56PM +0200, Niklas Schnelle wrote:
> The domain->geometry.aperture_end specifies the last valid address treat
> it as such when checking if a DMA address is valid.
>
> Reviewed-by: Pierre Morel <[email protected]>
> Reviewed-by: Matthew Rosato <[email protected]>
> Signed-off-by: Niklas Schnelle <[email protected]>
> ---
> v3->v4:
> - Make check robust against overflow (Jason)

I wish this value was called "last" but..

Reviewed-by: Jason Gunthorpe <[email protected]>

Jason