Unity Linux 20.1070a Security Update: kernel (UTSA-2026-013494)

medium Nessus Plugin ID 309326

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-2026-013494 advisory.

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

vhost: fix hung thread due to erroneous iotlb entries

In vhost_iotlb_add_range_ctx(), range size can overflow to 0 when start is 0 and last is ULONG_MAX. One instance where it can happen is when userspace sends an IOTLB message with iova=size=uaddr=0 (vhost_process_iotlb_msg). So, an entry with size = 0, start = 0, last = ULONG_MAX ends up in the iotlb. Next time a packet is sent, iotlb_access_ok() loops indefinitely due to that erroneous entry.

Call Trace:
<TASK> iotlb_access_ok+0x21b/0x3e0 drivers/vhost/vhost.c:1340 vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366 vhost_transport_do_send_pkt+0xe0/0xfd0 drivers/vhost/vsock.c:104 vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK>

Reported by syzbot at:
https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87

To fix this, do two things:

1. Return -EINVAL in vhost_chr_write_iter() when userspace asks to map a range with size 0.
2. Fix vhost_iotlb_add_range_ctx() to handle the range [0, ULONG_MAX] by splitting it into two entries.

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: 309326

File Name: unity_linux_UTSA-2026-013494.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 4/22/2026

Updated: 4/22/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

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-2022-48862

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/UOS-Server/release, Host/UOS-Server/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 4/22/2026

Vulnerability Publication Date: 7/16/2024

Reference Information

CVE: CVE-2022-48862

Detections

Analytics