diff options
| author | Lu Baolu <baolu.lu@linux.intel.com> | 2021-02-25 14:14:54 +0800 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-03-04 13:22:28 +0100 |
| commit | 82c3cefb9f1652e7470f442ff96c613e8c8ed8f4 (patch) | |
| tree | 740897d9eecf2e4da4e672e17137bc2df3caf163 | |
| parent | 765a9d1d02b2f5996b05f5f65faa8a634adbe763 (diff) | |
| download | linux-82c3cefb9f1652e7470f442ff96c613e8c8ed8f4.tar.bz2 | |
iommu: Don't use lazy flush for untrusted device
The lazy IOTLB flushing setup leaves a time window, in which the device
can still access some system memory, which has already been unmapped by
the device driver. It's not suitable for untrusted devices. A malicious
device might use this to attack the system by obtaining data that it
shouldn't obtain.
Fixes: c588072bba6b5 ("iommu/vt-d: Convert intel iommu driver to the iommu ops")
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210225061454.2864009-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
| -rw-r--r-- | drivers/iommu/dma-iommu.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index f659395e7959..65234e383d6b 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -311,6 +311,11 @@ static void iommu_dma_flush_iotlb_all(struct iova_domain *iovad) domain->ops->flush_iotlb_all(domain); } +static bool dev_is_untrusted(struct device *dev) +{ + return dev_is_pci(dev) && to_pci_dev(dev)->untrusted; +} + /** * iommu_dma_init_domain - Initialise a DMA mapping domain * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() @@ -365,8 +370,9 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, init_iova_domain(iovad, 1UL << order, base_pfn); - if (!cookie->fq_domain && !iommu_domain_get_attr(domain, - DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, &attr) && attr) { + if (!cookie->fq_domain && (!dev || !dev_is_untrusted(dev)) && + !iommu_domain_get_attr(domain, DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, &attr) && + attr) { if (init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all, iommu_dma_entry_dtor)) pr_warn("iova flush queue initialization failed\n"); @@ -508,11 +514,6 @@ static void __iommu_dma_unmap_swiotlb(struct device *dev, dma_addr_t dma_addr, iova_align(iovad, size), dir, attrs); } -static bool dev_is_untrusted(struct device *dev) -{ - return dev_is_pci(dev) && to_pci_dev(dev)->untrusted; -} - static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys, size_t size, int prot, u64 dma_mask) { |