From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756145Ab3LQScu (ORCPT ); Tue, 17 Dec 2013 13:32:50 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:60960 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755772Ab3LQSOz (ORCPT ); Tue, 17 Dec 2013 13:14:55 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Julian Stecklina , Joerg Roedel , Josh Boyer , Luis Henriques Subject: [PATCH 3.5 052/103] iommu/vt-d: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits Date: Tue, 17 Dec 2013 18:12:41 +0000 Message-Id: <1387304012-23805-53-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1387304012-23805-1-git-send-email-luis.henriques@canonical.com> References: <1387304012-23805-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.28 -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 Cc: Josh Boyer Signed-off-by: Luis Henriques --- drivers/iommu/intel-iommu.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index e560f54..f3535d9 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -779,7 +779,11 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain, 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) { -- 1.8.3.2