Detections
Analytics

Unity Linux 20.1070a Security Update: kernel (UTSA-2025-986460)

medium Nessus Plugin ID 267935

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-2025-986460 advisory.

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

 PCI: pciehp: Fix infinite loop in IRQ handler upon power fault

 The Power Fault Detected bit in the Slot Status register differs from all other hotplug events in that it is sticky: It can only be cleared after turning off slot power. Per PCIe r5.0, sec. 6.7.1.8:

 If a power controller detects a main power fault on the hot-plug slot, it must automatically set its internal main power fault latch [...].
 The main power fault latch is cleared when software turns off power to the hot-plug slot.

 The stickiness used to cause interrupt storms and infinite loops which were fixed in 2009 by commits 5651c48cfafe (PCI pciehp: fix power fault interrupt storm problem) and 99f0169c17f3 (PCI: pciehp: enable software notification on empty slots).

 Unfortunately in 2020 the infinite loop issue was inadvertently reintroduced by commit 8edf5332c393 (PCI: pciehp: Fix MSI interrupt race): The hardirq handler pciehp_isr() clears the PFD bit until pciehp's power_fault_detected flag is set. That happens in the IRQ thread pciehp_ist(), which never learns of the event because the hardirq handler is stuck in an infinite loop. Fix by setting the power_fault_detected flag already in the hardirq handler.

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.

See Also

http://www.nessus.org/u?7824b362

http://www.nessus.org/u?59101baf

https://nvd.nist.gov/vuln/detail/CVE-2021-47617

Plugin Details

Severity: Medium

ID: 267935

File Name: unity_linux_UTSA-2025-986460.nasl

Version: 1.1

Type: local

Published: 10/7/2025

Updated: 10/7/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

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-2021-47617

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: 9/22/2025

Vulnerability Publication Date: 3/8/2022

Reference Information

CVE: CVE-2021-47617