iommu/vt-d: fix memory leakage caused by commit ea8ea46
Commit ea8ea46 "iommu/vt-d: Clean up and fix page table clear/free
behaviour" introduces possible leakage of DMA page tables due to:
for (pte = page_address(pg); !first_pte_in_page(pte); pte++) {
if (dma_pte_present(pte) && !dma_pte_superpage(pte))
freelist = dma_pte_list_pagetables(domain, level - 1,
pte, freelist);
}
For the first pte in a page, first_pte_in_page(pte) will always be true,
thus dma_pte_list_pagetables() will never be called and leak DMA page
tables if level is bigger than 1.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 69fa7da..13dc231 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1009,11 +1009,13 @@
if (level == 1)
return freelist;
- for (pte = page_address(pg); !first_pte_in_page(pte); pte++) {
+ pte = page_address(pg);
+ do {
if (dma_pte_present(pte) && !dma_pte_superpage(pte))
freelist = dma_pte_list_pagetables(domain, level - 1,
pte, freelist);
- }
+ pte++;
+ } while (!first_pte_in_page(pte));
return freelist;
}