Unity Linux 20.1050a Security Update: kernel (UTSA-2026-053341)

medium Nessus Plugin ID 343138

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-2026-053341 advisory.

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

team: Move team device type change at the end of team_port_add

Attempting to add a port device that is already up will expectedly fail, but not before modifying the team device header_ops.

In the case of the syzbot reproducer the gre0 device is already in state UP when it attempts to add it as a port device of team0, this fails but before that header_ops->create of team0 is changed from eth_header to ipgre_header in the call to team_dev_type_check_change.

Later when we end up in ipgre_header() struct ip_tunnel* points to nonsense as the private data of the device still holds a struct team.

Example sequence of iproute2 commands to reproduce the hang/BUG():
ip link add dev team0 type team ip link add dev gre0 type gre ip link set dev gre0 up ip link set dev gre0 master team0 ip link set dev team0 up ping -I team0 1.1.1.1

Move team_dev_type_check_change down where all other checks have passed as it changes the dev type with no way to restore it in case one of the checks that follow it fail.

Also make sure to preserve the origial mtu assignment:
- If port_dev is not the same type as dev, dev takes mtu from port_dev
- If port_dev is the same type as dev, port_dev takes mtu from dev

This is done by adding a conditional before the call to dev_set_mtu to prevent it from assigning port_dev->mtu = dev->mtu and instead letting team_dev_type_check_change assign dev->mtu = port_dev->mtu.
The conditional is needed because the patch moves the call to team_dev_type_check_change past dev_set_mtu.

Testing:
- team device driver in-tree selftests
- Add/remove various devices as slaves of team device
- syzbot

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: 343138

File Name: unity_linux_UTSA-2026-053341.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 9/6/2026

Updated: 9/6/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.44

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-2025-68340

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: 7/27/2026

Vulnerability Publication Date: 12/23/2025

Reference Information

CVE: CVE-2025-68340

Detections

Analytics