Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986504)

high Nessus Plugin ID 268742

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-2025-986504 advisory.

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

kprobes: Fix possible use-after-free issue on kprobe registration

When unloading a module, its state is changing MODULE_STATE_LIVE -> MODULE_STATE_GOING -> MODULE_STATE_UNFORMED. Each change will take a time. `is_module_text_address()` and `__module_text_address()` works with MODULE_STATE_LIVE and MODULE_STATE_GOING.
If we use `is_module_text_address()` and `__module_text_address()` separately, there is a chance that the first one is succeeded but the next one is failed because module->state becomes MODULE_STATE_UNFORMED between those operations.

In `check_kprobe_address_safe()`, if the second `__module_text_address()` is failed, that is ignored because it expected a kernel_text address.
But it may have failed simply because module->state has been changed to MODULE_STATE_UNFORMED. In this case, arm_kprobe() will try to modify non-exist module text address (use-after-free).

To fix this problem, we should not use separated `is_module_text_address()` and `__module_text_address()`, but use only `__module_text_address()` once and do `try_module_get(module)` which is only available with MODULE_STATE_LIVE.

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: High

ID: 268742

File Name: unity_linux_UTSA-2025-986504.nasl

Version: 1.2

Type: local

Family: Unity Linux Local Security Checks

Published: 10/7/2025

Updated: 10/15/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 9

Temporal Score: 6.7

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

CVSS Score Source: CVE-2024-35955

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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: 4/9/2024

Reference Information

CVE: CVE-2024-35955

Detections

Analytics