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

Niklas Schnelle
2022-10-17T12:46:19Z

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 <pmorel@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
---
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