From 2a46ddf77c32da1f4137aeb902bc4e1f50582b69 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Fri, 11 Jul 2014 14:19:30 +0800 Subject: [PATCH] iommu/vt-d: Fix possible invalid memory access caused by free_dmar_iommu() 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 Signed-off-by: Joerg Roedel --- 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 968e3d32e305..0984fa58d872 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; @@ -1465,8 +1467,7 @@ 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)) { @@ -1479,11 +1480,7 @@ 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); } } -- 2.11.0