Unity Linux 20.1070e Security Update: kernel (UTSA-2025-987631)

high Nessus Plugin ID 270970

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-2025-987631 advisory.

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

staging: rtl8712: fix use-after-free in rtl8712_dl_fw

Syzbot reported use-after-free in rtl8712_dl_fw(). The problem was in race condition between r871xu_dev_remove() ->ndo_open() callback.

It's easy to see from crash log, that driver accesses released firmware in ->ndo_open() callback. It may happen, since driver was releasing firmware _before_ unregistering netdev. Fix it by moving unregister_netdev() before cleaning up resources.

Call Trace:
...
rtl871x_open_fw drivers/staging/rtl8712/hal_init.c:83 [inline] rtl8712_dl_fw+0xd95/0xe10 drivers/staging/rtl8712/hal_init.c:170 rtl8712_hal_init drivers/staging/rtl8712/hal_init.c:330 [inline] rtl871x_hal_init+0xae/0x180 drivers/staging/rtl8712/hal_init.c:394 netdev_open+0xe6/0x6c0 drivers/staging/rtl8712/os_intfs.c:380
__dev_open+0x2bc/0x4d0 net/core/dev.c:1484

Freed by task 1306:
...
release_firmware+0x1b/0x30 drivers/base/firmware_loader/main.c:1053 r871xu_dev_remove+0xcc/0x2c0 drivers/staging/rtl8712/usb_intf.c:599 usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458

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?246b1881

http://www.nessus.org/u?c57b42a9

https://nvd.nist.gov/vuln/detail/CVE-2021-47479

Plugin Details

Severity: High

ID: 270970

File Name: unity_linux_UTSA-2025-987631.nasl

Version: 1.1

Type: local

Published: 10/21/2025

Updated: 10/21/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Medium

Base Score: 6

Temporal Score: 4.4

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

CVSS Score Source: CVE-2021-47479

CVSS v3

Risk Factor: High

Base Score: 7

Temporal Score: 6.1

Vector: CVSS:3.0/AV:L/AC:H/PR:L/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: 10/15/2025

Vulnerability Publication Date: 7/21/2021

Reference Information

CVE: CVE-2021-47479