Unity Linux 20.1050e Security Update: kernel (UTSA-2025-991127)

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

include('compat.inc');

if (description)
{
  script_id(278220);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/12/11");

  script_cve_id("CVE-2022-50344");

  script_name(english:"Unity Linux 20.1050e Security Update: kernel (UTSA-2025-991127)");

  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-2025-991127 advisory.

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

    ext4: fix null-ptr-deref in ext4_write_info

    I caught a null-ptr-deref bug as follows:
    ==================================================================
    KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
    CPU: 1 PID: 1589 Comm: umount Not tainted 5.10.0-02219-dirty #339
    RIP: 0010:ext4_write_info+0x53/0x1b0
    [...]
    Call Trace:
     dquot_writeback_dquots+0x341/0x9a0
     ext4_sync_fs+0x19e/0x800
     __sync_filesystem+0x83/0x100
     sync_filesystem+0x89/0xf0
     generic_shutdown_super+0x79/0x3e0
     kill_block_super+0xa1/0x110
     deactivate_locked_super+0xac/0x130
     deactivate_super+0xb6/0xd0
     cleanup_mnt+0x289/0x400
     __cleanup_mnt+0x16/0x20
     task_work_run+0x11c/0x1c0
     exit_to_user_mode_prepare+0x203/0x210
     syscall_exit_to_user_mode+0x5b/0x3a0
     do_syscall_64+0x59/0x70
     entry_SYSCALL_64_after_hwframe+0x44/0xa9
     ==================================================================

    Above issue may happen as follows:
    -------------------------------------
    exit_to_user_mode_prepare
     task_work_run
      __cleanup_mnt
       cleanup_mnt
        deactivate_super
         deactivate_locked_super
          kill_block_super
           generic_shutdown_super
            shrink_dcache_for_umount
             dentry = sb->s_root
             sb->s_root = NULL              <--- Here set NULL
            sync_filesystem
             __sync_filesystem
              sb->s_op->sync_fs > ext4_sync_fs
               dquot_writeback_dquots
                sb->dq_op->write_info > ext4_write_info
                 ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2)
                  d_inode(sb->s_root)
                   s_root->d_inode          <--- Null pointer dereference

    To solve this problem, we use ext4_journal_start_sb directly
    to avoid s_root being used.

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-2025-991127
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9dfdcef0");
  # https://lore.kernel.org/linux-cve-announce/2025091639-CVE-2022-50344-8893@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?84a1ca61");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2022-50344");
  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-2022-50344");

  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:"2021/09/04");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/12/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/12/11");

  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:"^20.1050e([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1050e', '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': '1050e',
    'pkgs': [
      {'reference':'kernel-4.19.90-2211.5.0.0178.45', 'sp':'1050e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2211.5.0.0178.45', 'sp':'1050e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2211.5.0.0178.45', 'sp':'1050e', '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');
}