Unity Linux 20.1070a Security Update: kernel (UTSA-2026-005780)

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

include('compat.inc');

if (description)
{
  script_id(300668);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/03/04");

  script_cve_id("CVE-2023-53311");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2026-005780)");

  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-2026-005780 advisory.

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

    nilfs2: fix use-after-free of nilfs_root in dirtying inodes via iput

    During unmount process of nilfs2, nothing holds nilfs_root structure after
    nilfs2 detaches its writer in nilfs_detach_log_writer().  Previously,
    nilfs_evict_inode() could cause use-after-free read for nilfs_root if
    inodes are left in garbage_list and released by nilfs_dispose_list at
    the end of nilfs_detach_log_writer(), and this bug was fixed by commit
    9b5a04ac3ad9 (nilfs2: fix use-after-free bug of nilfs_root in
    nilfs_evict_inode()).

    However, it turned out that there is another possibility of UAF in the
    call path where mark_inode_dirty_sync() is called from iput():

    nilfs_detach_log_writer()
      nilfs_dispose_list()
        iput()
          mark_inode_dirty_sync()
            __mark_inode_dirty()
              nilfs_dirty_inode()
                __nilfs_mark_inode_dirty()
                  nilfs_load_inode_block() --> causes UAF of nilfs_root struct

    This can happen after commit 0ae45f63d4ef (vfs: add support for a
    lazytime mount option), which changed iput() to call
    mark_inode_dirty_sync() on its final reference if i_state has I_DIRTY_TIME
    flag and i_nlink is non-zero.

    This issue appears after commit 28a65b49eb53 (nilfs2: do not write dirty
    data after degenerating to read-only) when using the syzbot reproducer,
    but the issue has potentially existed before.

    Fix this issue by adding a purging flag to the nilfs structure, setting
    that flag while disposing the garbage_list and checking it in
    __nilfs_mark_inode_dirty().

    Unlike commit 9b5a04ac3ad9 (nilfs2: fix use-after-free bug of nilfs_root
    in nilfs_evict_inode()), this patch does not rely on ns_writer to
    determine whether to skip operations, so as not to break recovery on
    mount.  The nilfs_salvage_orphan_logs routine dirties the buffer of
    salvaged data before attaching the log writer, so changing
    __nilfs_mark_inode_dirty() to skip the operation when ns_writer is NULL
    will cause recovery write to fail.  The purpose of using the cleanup-only
    flag is to allow for narrowing of such conditions.

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-2026-005780
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?6e7b997c");
  # https://lore.kernel.org/linux-cve-announce/2025091642-CVE-2023-53311-bff3@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?5b1fc390");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2023-53311");
  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-2023-53311");

  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:"2021/07/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/03/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/03/04");

  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) 2026 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 && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1070a',
    'pkgs': [
      {'reference':'kernel-5.10.0-79.7', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.7', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.7', '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');
}