Unity Linux 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-011128)

medium Nessus Plugin ID 308470

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-2026-011128 advisory.

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

ring-buffer: Handle race between rb_move_tail and rb_check_pages

It seems a data race between ring_buffer writing and integrity check.
That is, RB_FLAG of head_page is been updating, while at same time RB_FLAG was cleared when doing integrity check rb_check_pages():

rb_check_pages() rb_handle_head_page():
-------- -------- rb_head_page_deactivate() rb_head_page_set_normal() rb_head_page_activate()

We do intergrity test of the list to check if the list is corrupted and it is still worth doing it. So, let's refactor rb_check_pages() such that we no longer clear and set flag during the list sanity checking.

[1] and [2] are the test to reproduce and the crash report respectively.

1:
``` read_trace.sh while true;
do # the trace file is closed after read head -1 /sys/kernel/tracing/trace > /dev/null done ``` ``` repro.sh sysctl -w kernel.panic_on_warn=1 # function tracer will writing enough data into ring_buffer echo function > /sys/kernel/tracing/current_tracer ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ```

2:
------------[ cut here ]------------ WARNING: CPU: 9 PID: 62 at kernel/trace/ring_buffer.c:2653 rb_move_tail+0x450/0x470 Modules linked in:
CPU: 9 PID: 62 Comm: ksoftirqd/9 Tainted: G W 6.2.0-rc6+ Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:rb_move_tail+0x450/0x470 Code: ff ff 4c 89 c8 f0 4d 0f b1 02 48 89 c2 48 83 e2 fc 49 39 d0 75 24 83 e0 03 83 f8 02 0f 84 e1 fb ff ff 48 8b 57 10 f0 ff 42 08 <0f> 0b 83 f8 02 0f 84 ce fb ff ff e9 db RSP: 0018:ffffb5564089bd00 EFLAGS: 00000203 RAX: 0000000000000000 RBX: ffff9db385a2bf81 RCX: ffffb5564089bd18 RDX: ffff9db281110100 RSI: 0000000000000fe4 RDI: ffff9db380145400 RBP: ffff9db385a2bf80 R08: ffff9db385a2bfc0 R09: ffff9db385a2bfc2 R10: ffff9db385a6c000 R11: ffff9db385a2bf80 R12: 0000000000000000 R13: 00000000000003e8 R14: ffff9db281110100 R15: ffffffffbb006108 FS: 0000000000000000(0000) GS:ffff9db3bdcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005602323024c8 CR3: 0000000022e0c000 CR4: 00000000000006e0 Call Trace:
<TASK> ring_buffer_lock_reserve+0x136/0x360 ? __do_softirq+0x287/0x2df ? __pfx_rcu_softirq_qs+0x10/0x10 trace_function+0x21/0x110 ? __pfx_rcu_softirq_qs+0x10/0x10 ? __do_softirq+0x287/0x2df function_trace_call+0xf6/0x120 0xffffffffc038f097 ? rcu_softirq_qs+0x5/0x140 rcu_softirq_qs+0x5/0x140
__do_softirq+0x287/0x2df run_ksoftirqd+0x2a/0x30 smpboot_thread_fn+0x188/0x220 ? __pfx_smpboot_thread_fn+0x10/0x10 kthread+0xe7/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 </TASK>
---[ end trace 0000000000000000 ]---

[ crash report and test reproducer credit goes to Zheng Yejian]

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.

See Also

http://www.nessus.org/u?52de0b63

http://www.nessus.org/u?34c9284f

https://nvd.nist.gov/vuln/detail/CVE-2023-53709

Plugin Details

Severity: Medium

ID: 308470

File Name: unity_linux_UTSA-2026-011128.nasl

Version: 1.1

Type: Local

Published: 4/21/2026

Updated: 4/21/2026

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:N/I:N/A:C

CVSS Score Source: CVE-2023-53709

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: 4/20/2026

Vulnerability Publication Date: 7/21/2021

Reference Information

CVE: CVE-2023-53709