Unity Linux 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-010704)

medium Nessus Plugin ID 308588

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-2026-010704 advisory.

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

sched/fair: Fix fault in reweight_entity

Syzbot found a GPF in reweight_entity. This has been bisected to commit 4ef0c5c6b5ba (kernel/sched: Fix sched_fork() access an invalid sched_task_group)

Thereis a race between sched_post_fork() and setpriority(PRIO_PGRP) within a thread group that causes a null-ptr-derefin reweight_entity() in CFS. The scenario is that the main process spawns number of new threads, which then call setpriority(PRIO_PGRP, 0, -20), wait, and exit. For each of the new threads the copy_process() gets invoked, which adds the new task_struct and calls sched_post_fork() for it.

In the above scenario there is a possibility that setpriority(PRIO_PGRP) and set_one_prio() will be called for a thread in the group that is just being created by copy_process(), and for which the sched_post_fork() has not been executed yet. This will trigger a null pointer dereference in reweight_entity(),as it will try to access the run queue pointer, which hasn't been set.

Before the mentioned change the cfs_rq pointer for the task has been set in sched_fork(), which is called much earlier in copy_process(), before the new task is added to the thread_group. Now it is done in the sched_post_fork(), which is called after that. To fix the issue the remove the update_load param from the update_load param() function and call reweight_task() only if the task flag doesn't have the TASK_NEW flag set.

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: 308588

File Name: unity_linux_UTSA-2026-010704.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 4/21/2026

Updated: 4/21/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Low

Base Score: 3.8

Temporal Score: 2.8

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

CVSS Score Source: CVE-2022-48921

CVSS v3

Risk Factor: Medium

Base Score: 4.7

Temporal Score: 4.1

Vector: CVSS:3.0/AV:L/AC:H/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/UOS-Server/release, Host/UOS-Server/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 4/20/2026

Vulnerability Publication Date: 7/21/2021

Reference Information

CVE: CVE-2022-48921

Detections

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