Unity Linux 20.1070a Security Update: kernel (UTSA-2026-143091)

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

include('compat.inc');

if (description)
{
  script_id(370578);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/22");

  script_cve_id("CVE-2026-68082");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2026-143091)");

  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-2026-143091 advisory.

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

    libceph: fix two unsafe bare decodes in decode_lockers()

    decode_lockers() in cls_lock_client.c contains two bare decode operations
    that allow a malicious or compromised OSD to trigger slab-out-of-bounds
    reads:

    1. ceph_decode_32(p) at the num_lockers field has no preceding bounds
       check. ceph_start_decoding() accepts struct_len=0 as valid -- the
       internal ceph_decode_need(p, end, 0, bad) always passes -- so when an
       OSD sends struct_len=0, ceph_start_decoding() returns success with
       p == end. The immediately following bare ceph_decode_32(p) then reads
       4 bytes past the validated buffer boundary. The garbage value is
       passed directly to kzalloc_objs() as the locker count.

       The sibling function decode_watchers() in osd_client.c already uses
       ceph_decode_32_safe() after its own ceph_start_decoding() call.
       decode_lockers() was the only site using the bare variant.

    2. ceph_decode_8(p) after the decode_locker() loop has no preceding
       bounds check. If an OSD crafts num_lockers such that the loop
       advances p exactly to end, the subsequent bare ceph_decode_8(p) reads
       one byte past the validated buffer boundary. The result is passed
       directly into *type, which is used as a lock type discriminator by
       callers, giving an OSD-controlled one-byte OOB read with direct
       influence over the lock type field.

    Fix both by replacing bare operations with their safe variants:
      ceph_decode_32(p) -> ceph_decode_32_safe(p, end, *num_lockers,
                                               err_inval)
      ceph_decode_8(p)  -> ceph_decode_8_safe(p, end, *type,
                                              err_free_lockers)

    The goto targets differ intentionally:
      err_inval: is a new label returning -EINVAL directly. It is used for
      the pre-allocation failure path where *lockers is not yet allocated
      and must not be passed to ceph_free_lockers().

      err_free_lockers: is the existing label. It is used for the
      post-allocation failure path where *lockers is allocated and must
      be freed.

    ret is set to -EINVAL before ceph_decode_8_safe() so that
    err_free_lockers returns the correct error code on bounds violation.
    Without this, err_free_lockers would return a stale ret value (0 from
    the successful decode_locker() loop), silently swallowing the error.

    -EINVAL is correct for both failure paths. The data received from the
    OSD is structurally malformed. -ENOMEM would misrepresent the failure
    class to callers and to stable@ backporters triaging error paths.

    Attacker model: a malicious or compromised OSD in a multi-tenant Ceph
    deployment can trigger this against any kernel client that issues the
    lock.get_info class method (e.g. during RBD exclusive lock acquisition).

    [ idryomov: trim changelog, formatting ]

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-2026-143091
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0a1f7326");
  # https://lore.kernel.org/linux-cve-announce/2026080834-CVE-2026-68082-fd5d@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?eaa2e3ee");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2026-68082");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/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:N/AC:L/PR:N/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-2026-68082");

  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:"2026/08/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/22");

  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 && 'loongarch64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1070a',
    'pkgs': [
      {'reference':'kernel-5.10.0-79.27.uelc20', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.27.uelc20', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.27.uelc20', 'sp':'1070a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.27.uelc20', '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_HOLE,
      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');
}