Unity Linux 20.1050e / 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-151160)

critical Nessus Plugin ID 378303

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-2026-151160 advisory.

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

ceph: fix UAF in check_new_map() on session freed during unlock

check_new_map() iterates mdsc->sessions[] and for each active session drops mdsc->mutex to perform per-session operations. The forced-close path (rank removed from map) correctly takes a reference on s via ceph_get_mds_session() before releasing mdsc->mutex, but three other paths do not:

Path A (address changed): mutex_unlock mutex_lock(&s->s_mutex) Path B (reconnect): mutex_unlock send_mds_reconnect(mdsc, s) Path C (active transition): mutex_unlock mutex_lock(&s->s_mutex)

Without the extra reference, another thread can acquire mdsc->mutex during the unlock window, call __unregister_session() which drops the last reference on s, and free it. The original thread then accesses freed memory via s->s_mutex.

Fix by adding ceph_get_mds_session(s) before each mutex_unlock and ceph_put_mds_session(s) after the corresponding mutex_lock, matching the pattern already used in the forced-close path.

Race timeline (Path A):

Thread A (check_new_map) Thread B (another map update holds mdsc->mutex or session teardown)
-------------------------- -------------------------- s = mdsc->sessions[i] (refcount == 1, held only by sessions[] array)

mutex_unlock(&mdsc->mutex)
---> acquires mdsc->mutex
__unregister_session(mdsc, s) sessions[i] = NULL ceph_put_mds_session(s) refcount: 1 -> 0 kfree(s) <--- freed!

mutex_lock(&s->s_mutex) UAF on freed s->s_mutex

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: Critical

ID: 378303

File Name: unity_linux_UTSA-2026-151160.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 11/10/2026

Updated: 11/10/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.51

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-89654

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/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: 11/10/2026

Vulnerability Publication Date: 9/11/2026

Reference Information

CVE: CVE-2026-89654

Detections

Analytics