Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753210AbcLFSZq (ORCPT ); Tue, 6 Dec 2016 13:25:46 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:15480 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752306AbcLFSZb (ORCPT ); Tue, 6 Dec 2016 13:25:31 -0500 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Mon, 05 Dec 2016 22:23:19 -0800 From: Kirti Wankhede To: , , , CC: , , , Kirti Wankhede Subject: [PATCH v2 1/2] vfio iommu type1: Fix size argument to vfio_find_dma() during DMA UNMAP. Date: Tue, 6 Dec 2016 23:56:54 +0530 Message-ID: <1481048814-29752-1-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1481044410-23862-1-git-send-email-kwankhede@nvidia.com> References: <1481044410-23862-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1351 Lines: 33 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 size - 1 and so it works correctly. Signed-off-by: Kirti Wankhede Signed-off-by: Neo Jia --- 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 a28fbddb505c..8e9e94ccb2ff 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; -- 2.7.0