From 7c03f428464333589f0c374b833af95777eb9dd8 Mon Sep 17 00:00:00 2001 From: Kirti Wankhede Date: Tue, 6 Dec 2016 23:56:54 +0530 Subject: [PATCH] vfio iommu type1: Fix size argument to vfio_find_dma() during DMA UNMAP. 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. Due to this, in vfio_dma_do_unmap(), while checking boundary conditions, size should be set to 1 for verifying start address of unmap range. vfio_find_dma() is also used to verify last address in unmap range with size = 0, but in that case address to be searched is calculated with start + size - 1 and so it works correctly. Signed-off-by: Kirti Wankhede Signed-off-by: Neo Jia [aw: changelog tweak] Signed-off-by: Alex Williamson --- drivers/vfio/vfio_iommu_type1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 7274fe27ccac..198cf398427e 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -826,7 +826,7 @@ again: * mappings within the range. */ if (iommu->v2) { - dma = vfio_find_dma(iommu, unmap->iova, 0); + dma = vfio_find_dma(iommu, unmap->iova, 1); if (dma && dma->iova != unmap->iova) { ret = -EINVAL; goto unlock; -- 2.20.1