From d8b8591054575f33237556c32762d54e30774d28 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Fri, 1 Mar 2019 11:23:10 +0800 Subject: iommu/vt-d: Disable ATS support on untrusted devices Commit fb58fdcd295b9 ("iommu/vt-d: Do not enable ATS for untrusted devices") disables ATS support on the devices which have been marked as untrusted. Unfortunately this is not enough to fix the DMA attack vulnerabiltiies because IOMMU driver allows translated requests as long as a device advertises the ATS capability. Hence a malicious peripheral device could use this to bypass IOMMU. This disables the ATS support on untrusted devices by clearing the internal per-device ATS mark. As the result, IOMMU driver will block any translated requests from any device marked as untrusted. Cc: Jacob Pan Cc: Mika Westerberg Suggested-by: Kevin Tian Suggested-by: Ashok Raj Fixes: fb58fdcd295b9 ("iommu/vt-d: Do not enable ATS for untrusted devices") Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index c30b73d41bf2..64ce780336a8 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -2484,7 +2484,8 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu, if (dev && dev_is_pci(dev)) { struct pci_dev *pdev = to_pci_dev(info->dev); - if (!pci_ats_disabled() && + if (!pdev->untrusted && + !pci_ats_disabled() && ecap_dev_iotlb_support(iommu->ecap) && pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS) && dmar_find_matched_atsr_unit(pdev)) -- cgit v1.2.3