Unity Linux 20.1050a Security Update: kernel (UTSA-2026-100365)

medium Nessus Plugin ID 336830

Synopsis

The Unity Linux host is missing one or more security updates.

Description

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-100365 advisory.

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

iommu/vt-d: Flush dev-IOTLB only when PCIe device is accessible in scalable mode

Commit 4fc82cd907ac (iommu/vt-d: Don't issue ATS Invalidation request when device is disconnected) relies on pci_dev_is_disconnected() to skip ATS invalidation for safely-removed devices, but it does not cover link-down caused by faults, which can still hard-lock the system.

For example, if a VM fails to connect to the PCIe device, virsh destroy is executed to release resources and isolate the fault, but a hard-lockup occurs while releasing the group fd.

Call Trace:
qi_submit_sync qi_flush_dev_iotlb intel_pasid_tear_down_entry device_block_translation blocking_domain_attach_dev
__iommu_attach_device
__iommu_device_set_domain
__iommu_group_set_domain_internal iommu_detach_group vfio_iommu_type1_detach_group vfio_group_detach_container vfio_group_fops_release
__fput

Although pci_device_is_present() is slower than pci_dev_is_disconnected(), it still takes only ~70 s on a ConnectX-5 (8 GT/s, x2) and becomes even faster as PCIe speed and width increase.

Besides, devtlb_invalidation_with_pasid() is called only in the paths below, which are far less frequent than memory map/unmap.

1. mm-struct release 2. {attach,release}_dev 3. set/remove PASID 4. dirty-tracking setup

The gain in system stability far outweighs the negligible cost of using pci_device_is_present() instead of pci_dev_is_disconnected() to decide when to skip ATS invalidation, especially under GDR high-load conditions.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected kernel package.

Plugin Details

Severity: Medium

ID: 336830

File Name: unity_linux_UTSA-2026-100365.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 8/17/2026

Updated: 8/17/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.68

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C

CVSS Score Source: CVE-2026-43130

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/UOS-Server/release, Host/UOS-Server/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 8/13/2026

Vulnerability Publication Date: 4/7/2026

Reference Information

CVE: CVE-2026-43130

Detections

Analytics