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Commit 2a46ddf7 authored by Jiang Liu's avatar Jiang Liu Committed by Joerg Roedel
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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: default avatarJiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 44bde614

drivers/iommu/intel-iommu.c

+4 −7
Original line number Diff line number Diff line
@@ -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);

		}

	}