From 2b8bb1d771f736b8b34bf160115aee1b12d29f83 Mon Sep 17 00:00:00 2001 From: Kirti Wankhede Date: Tue, 6 Dec 2016 23:58:12 +0530 Subject: [PATCH] vfio iommu type1: Fix size argument to vfio_find_dma() in pin_pages/unpin_pages Passing zero for the size to vfio_find_dma() isn't compatible with matching the start address of an existing vfio_dma. Doing so triggers a corner case. In vfio_find_dma(), when the start address is equal to dma->iova and size is 0, check for the end of search range makes it to take wrong side of RB-tree. That fails the search even though the address is present in mapped dma ranges. In functions pin_pages and unpin_pages, the iova which is being searched is base address of page to be pinned or unpinned. So here size should be set to PAGE_SIZE, as argument to vfio_find_dma(). Signed-off-by: Kirti Wankhede Signed-off-by: Neo Jia Signed-off-by: Alex Williamson --- drivers/vfio/vfio_iommu_type1.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 198cf398427e..9815e45c23c4 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -581,7 +581,7 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, struct vfio_pfn *vpfn; iova = user_pfn[i] << PAGE_SHIFT; - dma = vfio_find_dma(iommu, iova, 0); + dma = vfio_find_dma(iommu, iova, PAGE_SIZE); if (!dma) { ret = -EINVAL; goto pin_unwind; @@ -622,7 +622,7 @@ pin_unwind: dma_addr_t iova; iova = user_pfn[j] << PAGE_SHIFT; - dma = vfio_find_dma(iommu, iova, 0); + dma = vfio_find_dma(iommu, iova, PAGE_SIZE); vfio_unpin_page_external(dma, iova, do_accounting); phys_pfn[j] = 0; } @@ -659,7 +659,7 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data, dma_addr_t iova; iova = user_pfn[i] << PAGE_SHIFT; - dma = vfio_find_dma(iommu, iova, 0); + dma = vfio_find_dma(iommu, iova, PAGE_SIZE); if (!dma) goto unpin_exit; vfio_unpin_page_external(dma, iova, do_accounting); -- 2.39.5