Unity Linux 20.1070a Security Update: kernel (UTSA-2025-988986)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(273548);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/05");

  script_cve_id("CVE-2021-47379");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2025-988986)");

  script_set_attribute(attribute:"synopsis", value:
"The Unity Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the
UTSA-2025-988986 advisory.

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

    blk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd

    KASAN reports a use-after-free report when doing fuzz test:

    [693354.104835] ==================================================================
    [693354.105094] BUG: KASAN: use-after-free in bfq_io_set_weight_legacy+0xd3/0x160
    [693354.105336] Read of size 4 at addr ffff888be0a35664 by task sh/1453338

    [693354.105607] CPU: 41 PID: 1453338 Comm: sh Kdump: loaded Not tainted 4.18.0-147
    [693354.105610] Hardware name: Huawei 2288H V5/BC11SPSCB0, BIOS 0.81 07/02/2018
    [693354.105612] Call Trace:
    [693354.105621]  dump_stack+0xf1/0x19b
    [693354.105626]  ? show_regs_print_info+0x5/0x5
    [693354.105634]  ? printk+0x9c/0xc3
    [693354.105638]  ? cpumask_weight+0x1f/0x1f
    [693354.105648]  print_address_description+0x70/0x360
    [693354.105654]  kasan_report+0x1b2/0x330
    [693354.105659]  ? bfq_io_set_weight_legacy+0xd3/0x160
    [693354.105665]  ? bfq_io_set_weight_legacy+0xd3/0x160
    [693354.105670]  bfq_io_set_weight_legacy+0xd3/0x160
    [693354.105675]  ? bfq_cpd_init+0x20/0x20
    [693354.105683]  cgroup_file_write+0x3aa/0x510
    [693354.105693]  ? ___slab_alloc+0x507/0x540
    [693354.105698]  ? cgroup_file_poll+0x60/0x60
    [693354.105702]  ? 0xffffffff89600000
    [693354.105708]  ? usercopy_abort+0x90/0x90
    [693354.105716]  ? mutex_lock+0xef/0x180
    [693354.105726]  kernfs_fop_write+0x1ab/0x280
    [693354.105732]  ? cgroup_file_poll+0x60/0x60
    [693354.105738]  vfs_write+0xe7/0x230
    [693354.105744]  ksys_write+0xb0/0x140
    [693354.105749]  ? __ia32_sys_read+0x50/0x50
    [693354.105760]  do_syscall_64+0x112/0x370
    [693354.105766]  ? syscall_return_slowpath+0x260/0x260
    [693354.105772]  ? do_page_fault+0x9b/0x270
    [693354.105779]  ? prepare_exit_to_usermode+0xf9/0x1a0
    [693354.105784]  ? enter_from_user_mode+0x30/0x30
    [693354.105793]  entry_SYSCALL_64_after_hwframe+0x65/0xca

    [693354.105875] Allocated by task 1453337:
    [693354.106001]  kasan_kmalloc+0xa0/0xd0
    [693354.106006]  kmem_cache_alloc_node_trace+0x108/0x220
    [693354.106010]  bfq_pd_alloc+0x96/0x120
    [693354.106015]  blkcg_activate_policy+0x1b7/0x2b0
    [693354.106020]  bfq_create_group_hierarchy+0x1e/0x80
    [693354.106026]  bfq_init_queue+0x678/0x8c0
    [693354.106031]  blk_mq_init_sched+0x1f8/0x460
    [693354.106037]  elevator_switch_mq+0xe1/0x240
    [693354.106041]  elevator_switch+0x25/0x40
    [693354.106045]  elv_iosched_store+0x1a1/0x230
    [693354.106049]  queue_attr_store+0x78/0xb0
    [693354.106053]  kernfs_fop_write+0x1ab/0x280
    [693354.106056]  vfs_write+0xe7/0x230
    [693354.106060]  ksys_write+0xb0/0x140
    [693354.106064]  do_syscall_64+0x112/0x370
    [693354.106069]  entry_SYSCALL_64_after_hwframe+0x65/0xca

    [693354.106114] Freed by task 1453336:
    [693354.106225]  __kasan_slab_free+0x130/0x180
    [693354.106229]  kfree+0x90/0x1b0
    [693354.106233]  blkcg_deactivate_policy+0x12c/0x220
    [693354.106238]  bfq_exit_queue+0xf5/0x110
    [693354.106241]  blk_mq_exit_sched+0x104/0x130
    [693354.106245]  __elevator_exit+0x45/0x60
    [693354.106249]  elevator_switch_mq+0xd6/0x240
    [693354.106253]  elevator_switch+0x25/0x40
    [693354.106257]  elv_iosched_store+0x1a1/0x230
    [693354.106261]  queue_attr_store+0x78/0xb0
    [693354.106264]  kernfs_fop_write+0x1ab/0x280
    [693354.106268]  vfs_write+0xe7/0x230
    [693354.106271]  ksys_write+0xb0/0x140
    [693354.106275]  do_syscall_64+0x112/0x370
    [693354.106280]  entry_SYSCALL_64_after_hwframe+0x65/0xca

    [693354.106329] The buggy address belongs to the object at ffff888be0a35580
                     which belongs to the cache kmalloc-1k of size 1024
    [693354.106736] The buggy address is located 228 bytes inside of
                     1024-byte region [ffff888be0a35580, ffff888be0a35980)
    [693354.107114] The buggy address belongs to the page:
    [693354.107273] page:ffffea002f828c00 count:1 mapcount:0 mapping:ffff888107c17080 index:0x0
    compound_mapcount: 0
    [693354.107606] flags: 0x17ffffc0008100(slab|head)
    [693354.107760] raw: 0017ffffc0008100 ffffea002fcbc808 ffffea0030bd3a08 ffff888107c17080
    [693354.108020] r
    ---truncated---

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.");
  # https://src.uniontech.com/#/security_advisory_detail?utsa_id=UTSA-2025-988986
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?fd1ec2da");
  # https://lore.kernel.org/linux-cve-announce/2024052142-CVE-2021-47379-58ec@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?6ccf6d9d");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2021-47379");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-47379");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2022/01/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/11/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/11/05");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Unity Linux Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/UOS-Server/release", "Host/UOS-Server/rpm-list", "Host/cpu");

  exit(0);
}
include('rpm2.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_product = get_kb_item('installed_os/local/SSH/0/product');
if (isnull(os_product) || 'UOS Server' >!< os_product) audit(AUDIT_OS_NOT, 'UOS Server');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'UOS Server');
if (! preg(pattern:"^20.1070a([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1070a', 'UOS Server ' + os_version);

if (!get_kb_item('Host/UOS-Server/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('aarch64' >!< cpu && 'amd64' >!< cpu && 'loongarch64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1070a',
    'pkgs': [
      {'reference':'kernel-5.10.0-79.4.2', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.4.2', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.4.2', 'sp':'1070a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.4.2', 'sp':'1070a', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  }
];

var os_release = get_one_kb_item('installed_os/local/SSH/0/release');
var os_sp = get_one_kb_item('Host/*/minor_release');

var flag = 0;
var reference;
var sp;
var _cpu;
var el_string;
var rpm_spec_vers_cmp;
var epoch;
var allowmaj;
var exists_check;
var cves;
foreach var constraint ( constraints ) {
  # Check that the target release is equal to the affected release
  if (!empty_or_null(constraint['release'])){
    if (constraint['release'] != os_release) continue;
  }
  if (!empty_or_null(constraint['sp'])){
    if (constraint['sp'] != os_sp) continue;
  }
  foreach var pkg ( constraint['pkgs'] ) {
    reference = NULL;
    sp = NULL;
    _cpu = NULL;
    el_string = NULL;
    rpm_spec_vers_cmp = NULL;
    epoch = NULL;
    allowmaj = NULL;
    exists_check = NULL;
    cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        ## (no known rpm to check OR known rpm_exists)
        (!exists_check || rpm_exists(rpm:exists_check)) &&
        rpm_check(sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj, cves:cves)) flag++;
  }
}


if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'kernel');
}