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Unity Linux 20.1050a / 20.1060a / 20.1070a Security Update: kernel (UTSA-2025-395876)

medium Nessus Plugin ID 267738

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-2025-395876 advisory.

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

 ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find()

 Syzbot reports a warning as follows:

 ============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 Modules linked in:
 CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419 Call Trace:
 <TASK> ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327 [...] ============================================

 This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage.

 So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.

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.

See Also

http://www.nessus.org/u?6e96c8e5

http://www.nessus.org/u?d5d12a13

https://nvd.nist.gov/vuln/detail/CVE-2024-39276

Plugin Details

Severity: Medium

ID: 267738

File Name: unity_linux_UTSA-2025-395876.nasl

Version: 1.1

Type: local

Published: 10/7/2025

Updated: 10/7/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2024-39276

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:H/I:N/A:N

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: 7/8/2025

Vulnerability Publication Date: 6/25/2024

Reference Information

CVE: CVE-2024-39276