From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com ([134.134.136.24]:54817 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934220AbaEFHEb (ORCPT ); Tue, 6 May 2014 03:04:31 -0400 From: Jiang Liu To: Joerg Roedel , David Woodhouse , Yinghai Lu , Bjorn Helgaas , Dan Williams , Vinod Koul , "Rafael J . Wysocki" Cc: Jiang Liu , Ashok Raj , Yijing Wang , Tony Luck , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, linux-hotplug@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org Subject: [Patch Part3 V2 06/21] iommu/vt-d: fix possible invalid memory access caused by free_dmar_iommu() Date: Tue, 6 May 2014 15:05:17 +0800 Message-Id: <1399359932-28972-7-git-send-email-jiang.liu@linux.intel.com> In-Reply-To: <1399359932-28972-1-git-send-email-jiang.liu@linux.intel.com> References: <1399359932-28972-1-git-send-email-jiang.liu@linux.intel.com> Sender: linux-pci-owner@vger.kernel.org List-ID: Static identity and virtual machine domains may be cached in iommu->domain_ids array after corresponding IOMMUs have been removed from domain->iommu_bmp. So we should check domain->iommu_bmp before decreasing domain->iommu_count in function free_dmar_iommu(), otherwise it may cause free of inuse domain data structure. Signed-off-by: Jiang Liu --- drivers/iommu/intel-iommu.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 0ab0cd236b16..1f10fcd1c696 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -425,6 +425,8 @@ static void domain_remove_one_dev_info(struct dmar_domain *domain, struct device *dev); static void iommu_detach_dependent_devices(struct intel_iommu *iommu, struct device *dev); +static int domain_detach_iommu(struct dmar_domain *domain, + struct intel_iommu *iommu); #ifdef CONFIG_INTEL_IOMMU_DEFAULT_ON int dmar_disabled = 0; @@ -1467,8 +1469,7 @@ static int iommu_init_domains(struct intel_iommu *iommu) static void free_dmar_iommu(struct intel_iommu *iommu) { struct dmar_domain *domain; - int i, count; - unsigned long flags; + int i; if ((iommu->domains) && (iommu->domain_ids)) { for_each_set_bit(i, iommu->domain_ids, cap_ndoms(iommu->cap)) { @@ -1481,11 +1482,7 @@ static void free_dmar_iommu(struct intel_iommu *iommu) domain = iommu->domains[i]; clear_bit(i, iommu->domain_ids); - - spin_lock_irqsave(&domain->iommu_lock, flags); - count = --domain->iommu_count; - spin_unlock_irqrestore(&domain->iommu_lock, flags); - if (count == 0) + if (domain_detach_iommu(domain, iommu) == 0) domain_exit(domain); } } -- 1.7.10.4