Unity Linux 20.1070a Security Update: kernel (UTSA-2026-005672)

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

include('compat.inc');

if (description)
{
  script_id(301010);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/03/05");

  script_cve_id("CVE-2022-50478");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2026-005672)");

  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-2026-005672 advisory.

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

    nilfs2: fix shift-out-of-bounds/overflow in nilfs_sb2_bad_offset()

    Patch series nilfs2: fix UBSAN shift-out-of-bounds warnings on mount
    time.

    The first patch fixes a bug reported by syzbot, and the second one fixes
    the remaining bug of the same kind.  Although they are triggered by the
    same super block data anomaly, I divided it into the above two because the
    details of the issues and how to fix it are different.

    Both are required to eliminate the shift-out-of-bounds issues at mount
    time.


    This patch (of 2):

    If the block size exponent information written in an on-disk superblock is
    corrupted, nilfs_sb2_bad_offset helper function can trigger
    shift-out-of-bounds warning followed by a kernel panic (if panic_on_warn
    is set):

     shift exponent 38983 is too large for 64-bit type 'unsigned long long'
     Call Trace:
      <TASK>
      __dump_stack lib/dump_stack.c:88 [inline]
      dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
      ubsan_epilogue lib/ubsan.c:151 [inline]
      __ubsan_handle_shift_out_of_bounds+0x33d/0x3b0 lib/ubsan.c:322
      nilfs_sb2_bad_offset fs/nilfs2/the_nilfs.c:449 [inline]
      nilfs_load_super_block+0xdf5/0xe00 fs/nilfs2/the_nilfs.c:523
      init_nilfs+0xb7/0x7d0 fs/nilfs2/the_nilfs.c:577
      nilfs_fill_super+0xb1/0x5d0 fs/nilfs2/super.c:1047
      nilfs_mount+0x613/0x9b0 fs/nilfs2/super.c:1317
      ...

    In addition, since nilfs_sb2_bad_offset() performs multiplication without
    considering the upper bound, the computation may overflow if the disk
    layout parameters are not normal.

    This fixes these issues by inserting preliminary sanity checks for those
    parameters and by converting the comparison from one involving
    multiplication and left bit-shifting to one using division and right
    bit-shifting.

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-2026-005672
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b229220e");
  # https://lore.kernel.org/linux-cve-announce/2025100438-CVE-2022-50478-81f8@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?cf469e89");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2022-50478");
  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: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:H/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-2022-50478");

  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:"2026/03/05");

  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) 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-4.19.0-91.82.190.007', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.190.007', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.190.007', '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');
}