From adeb25905c644350baf1f446bcd856517e58060e Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 9 Apr 2014 10:20:39 +0800 Subject: [PATCH] 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 Signed-off-by: David Woodhouse --- drivers/iommu/intel-iommu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 69fa7da5e48b..13dc2318e17a 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1009,11 +1009,13 @@ static struct page *dma_pte_list_pagetables(struct dmar_domain *domain, 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; } -- GitLab