From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161425Ab3LFWFE (ORCPT ); Fri, 6 Dec 2013 17:05:04 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:32813 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759479Ab3LFVx6 (ORCPT ); Fri, 6 Dec 2013 16:53:58 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Julian Stecklina , Alex Williamson , Joerg Roedel Subject: [PATCH 3.10 52/58] iommu/vt-d: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits Date: Fri, 6 Dec 2013 13:52:23 -0800 Message-Id: <20131206214849.709813126@linuxfoundation.org> X-Mailer: git-send-email 1.8.5.1.67.gb00d244 In-Reply-To: <20131206214844.906193530@linuxfoundation.org> References: <20131206214844.906193530@linuxfoundation.org> User-Agent: quilt/0.60-8.1.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Julian Stecklina commit f9423606ade08653dd8a43334f0a7fb45504c5cc upstream. The BUG_ON in drivers/iommu/intel-iommu.c:785 can be triggered from userspace via VFIO by calling the VFIO_IOMMU_MAP_DMA ioctl on a vfio device with any address beyond the addressing capabilities of the IOMMU. The problem is that the ioctl code calls iommu_iova_to_phys before it calls iommu_map. iommu_map handles the case that it gets addresses beyond the addressing capabilities of its IOMMU. intel_iommu_iova_to_phys does not. This patch fixes iommu_iova_to_phys to return NULL for addresses beyond what the IOMMU can handle. This in turn causes the ioctl call to fail in iommu_map and (correctly) return EFAULT to the user with a helpful warning message in the kernel log. Signed-off-by: Julian Stecklina Acked-by: Alex Williamson Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/intel-iommu.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -782,7 +782,11 @@ static struct dma_pte *pfn_to_dma_pte(st int offset; BUG_ON(!domain->pgd); - BUG_ON(addr_width < BITS_PER_LONG && pfn >> addr_width); + + if (addr_width < BITS_PER_LONG && pfn >> addr_width) + /* Address beyond IOMMU's addressing capabilities. */ + return NULL; + parent = domain->pgd; while (level > 0) {