Unity Linux 20.1070a Security Update: kernel (UTSA-2025-989906)

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

include('compat.inc');

if (description)
{
  script_id(273675);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/05");

  script_cve_id("CVE-2021-47299");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2025-989906)");

  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-2025-989906 advisory.

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

    xdp, net: Fix use-after-free in bpf_xdp_link_release

    The problem occurs between dev_get_by_index() and dev_xdp_attach_link().
    At this point, dev_xdp_uninstall() is called. Then xdp link will not be
    detached automatically when dev is released. But link->dev already
    points to dev, when xdp link is released, dev will still be accessed,
    but dev has been released.

    dev_get_by_index()        |
    link->dev = dev           |
                              |      rtnl_lock()
                              |      unregister_netdevice_many()
                              |          dev_xdp_uninstall()
                              |      rtnl_unlock()
    rtnl_lock();              |
    dev_xdp_attach_link()     |
    rtnl_unlock();            |
                              |      netdev_run_todo() // dev released
    bpf_xdp_link_release()    |
        /* access dev.        |
           use-after-free */  |

    [   45.966867] BUG: KASAN: use-after-free in bpf_xdp_link_release+0x3b8/0x3d0
    [   45.967619] Read of size 8 at addr ffff00000f9980c8 by task a.out/732
    [   45.968297]
    [   45.968502] CPU: 1 PID: 732 Comm: a.out Not tainted 5.13.0+ #22
    [   45.969222] Hardware name: linux,dummy-virt (DT)
    [   45.969795] Call trace:
    [   45.970106]  dump_backtrace+0x0/0x4c8
    [   45.970564]  show_stack+0x30/0x40
    [   45.970981]  dump_stack_lvl+0x120/0x18c
    [   45.971470]  print_address_description.constprop.0+0x74/0x30c
    [   45.972182]  kasan_report+0x1e8/0x200
    [   45.972659]  __asan_report_load8_noabort+0x2c/0x50
    [   45.973273]  bpf_xdp_link_release+0x3b8/0x3d0
    [   45.973834]  bpf_link_free+0xd0/0x188
    [   45.974315]  bpf_link_put+0x1d0/0x218
    [   45.974790]  bpf_link_release+0x3c/0x58
    [   45.975291]  __fput+0x20c/0x7e8
    [   45.975706]  ____fput+0x24/0x30
    [   45.976117]  task_work_run+0x104/0x258
    [   45.976609]  do_notify_resume+0x894/0xaf8
    [   45.977121]  work_pending+0xc/0x328
    [   45.977575]
    [   45.977775] The buggy address belongs to the page:
    [   45.978369] page:fffffc00003e6600 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4f998
    [   45.979522] flags: 0x7fffe0000000000(node=0|zone=0|lastcpupid=0x3ffff)
    [   45.980349] raw: 07fffe0000000000 fffffc00003e6708 ffff0000dac3c010 0000000000000000
    [   45.981309] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
    [   45.982259] page dumped because: kasan: bad access detected
    [   45.982948]
    [   45.983153] Memory state around the buggy address:
    [   45.983753]  ffff00000f997f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
    [   45.984645]  ffff00000f998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
    [   45.985533] >ffff00000f998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
    [   45.986419]                                               ^
    [   45.987112]  ffff00000f998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
    [   45.988006]  ffff00000f998180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
    [   45.988895] ==================================================================
    [   45.989773] Disabling lock debugging due to kernel taint
    [   45.990552] Kernel panic - not syncing: panic_on_warn set ...
    [   45.991166] CPU: 1 PID: 732 Comm: a.out Tainted: G    B             5.13.0+ #22
    [   45.991929] Hardware name: linux,dummy-virt (DT)
    [   45.992448] Call trace:
    [   45.992753]  dump_backtrace+0x0/0x4c8
    [   45.993208]  show_stack+0x30/0x40
    [   45.993627]  dump_stack_lvl+0x120/0x18c
    [   45.994113]  dump_stack+0x1c/0x34
    [   45.994530]  panic+0x3a4/0x7d8
    [   45.994930]  end_report+0x194/0x198
    [   45.995380]  kasan_report+0x134/0x200
    [   45.995850]  __asan_report_load8_noabort+0x2c/0x50
    [   45.996453]  bpf_xdp_link_release+0x3b8/0x3d0
    [   45.997007]  bpf_link_free+0xd0/0x188
    [   45.997474]  bpf_link_put+0x1d0/0x218
    [   45.997942]  bpf_link_release+0x3c/0x58
    [   45.998429]  __fput+0x20c/0x7e8
    [   45.998833]  ____fput+0x24/0x30
    [   45.999247]  task_work_run+0x104/0x258
    [   45.999731]  do_notify_resume+0x894/0xaf8
    [   46.000236]  work_pending
    ---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-2025-989906
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?fd099eea");
  # https://lore.kernel.org/linux-cve-announce/2024052125-CVE-2021-47299-e1d9@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?60cc513a");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2021-47299");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:N/I:N/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:N/I:N/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-2021-47299");

  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');
}