CVE-2026-43161

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode

PCIe endpoints with ATS enabled and passed through to userspace

(e.g., QEMU, DPDK) can hard-lock the host when their link drops,

either by surprise removal or by a link fault.

Commit 4fc82cd907ac ("iommu/vt-d: Don't issue ATS Invalidation

request when device is disconnected") adds pci_dev_is_disconnected()

to devtlb_invalidation_with_pasid() so ATS invalidation is skipped

only when the device is being safely removed, but it applies only

when Intel IOMMU scalable mode is enabled.

With scalable mode disabled or unsupported, a system hard-lock

occurs when a PCIe endpoint's link drops because the Intel IOMMU

waits indefinitely for an ATS invalidation that cannot complete.

Call Trace:

qi_submit_sync

qi_flush_dev_iotlb

__context_flush_dev_iotlb.part.0

domain_context_clear_one_cb

pci_for_each_dma_alias

device_block_translation

bloc

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References