Unity Linux 20.1060a Security Update: kernel (UTSA-2026-014323)

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

include('compat.inc');

if (description)
{
  script_id(310376);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/26");

  script_cve_id("CVE-2025-68774");

  script_name(english:"Unity Linux 20.1060a Security Update: kernel (UTSA-2026-014323)");

  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-2026-014323 advisory.

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

    hfsplus: fix missing hfs_bnode_get() in __hfs_bnode_create

    When sync() and link() are called concurrently, both threads may
    enter hfs_bnode_find() without finding the node in the hash table
    and proceed to create it.

    Thread A:
      hfsplus_write_inode()
        -> hfsplus_write_system_inode()
          -> hfs_btree_write()
            -> hfs_bnode_find(tree, 0)
              -> __hfs_bnode_create(tree, 0)

    Thread B:
      hfsplus_create_cat()
        -> hfs_brec_insert()
          -> hfs_bnode_split()
            -> hfs_bmap_alloc()
              -> hfs_bnode_find(tree, 0)
                -> __hfs_bnode_create(tree, 0)

    In this case, thread A creates the bnode, sets refcnt=1, and hashes it.
    Thread B also tries to create the same bnode, notices it has already
    been inserted, drops its own instance, and uses the hashed one without
    getting the node.

    ```

            node2 = hfs_bnode_findhash(tree, cnid);
            if (!node2) {                                 <- Thread A
                    hash = hfs_bnode_hash(cnid);
                    node->next_hash = tree->node_hash[hash];
                    tree->node_hash[hash] = node;
                    tree->node_hash_cnt++;
            } else {                                      <- Thread B
                    spin_unlock(&tree->hash_lock);
                    kfree(node);
                    wait_event(node2->lock_wq,
                            !test_bit(HFS_BNODE_NEW, &node2->flags));
                    return node2;
            }
    ```

    However, hfs_bnode_find() requires each call to take a reference.
    Here both threads end up setting refcnt=1. When they later put the node,
    this triggers:

    BUG_ON(!atomic_read(&node->refcnt))

    In this scenario, Thread B in fact finds the node in the hash table
    rather than creating a new one, and thus must take a reference.

    Fix this by calling hfs_bnode_get() when reusing a bnode newly created by
    another thread to ensure the refcount is updated correctly.

    A similar bug was fixed in HFS long ago in commit
    a9dc087fd3c4 (fix missing hfs_bnode_get() in __hfs_bnode_create)
    but the same issue remained in HFS+ until now.

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-2026-014323
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?fde09acc");
  # https://lore.kernel.org/linux-cve-announce/2026011358-CVE-2025-68774-f2fd@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0af0a020");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2025-68774");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/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:H/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-2025-68774");

  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:"2026/01/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/04/26");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/04/26");

  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:"^20.1060a([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1060a', '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) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1060a',
    'pkgs': [
      {'reference':'kernel-5.10.0-38', 'sp':'1060a', 'cpu':'aarch64', '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_NOTE,
      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');
}