Unity Linux 20.1070a Security Update: kernel (UTSA-2026-143076)

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

include('compat.inc');

if (description)
{
  script_id(370741);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/22");

  script_cve_id("CVE-2026-68117");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2026-143076)");

  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-2026-143076 advisory.

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

    tipc: clear sock->sk on the failed-insert path in tipc_sk_create()

    When tipc_sk_create() fails to insert the new socket (tipc_sk_insert()
    returns non-zero), its error path frees the sk with sk_free() but leaves
    sock->sk pointing at the freed object:

            if (tipc_sk_insert(tsk)) {
                    sk_free(sk);
                    pr_warn(Socket create failed; port number exhausted
    );
                    return -EINVAL;
            }

    This is harmless for plain socket(): the syscall layer clears sock->ops
    before releasing, so tipc_release() is never called. It is not harmless
    on the accept() path. tipc_accept() creates the pre-allocated child
    socket with tipc_sk_create(net, new_sock, 0, kern); on failure it leaves
    new_sock->sk dangling and new_sock->ops non-NULL, and do_accept() then
    fput()s the new file, so __sock_release() -> tipc_release() runs
    lock_sock(new_sock->sk) on the freed sk -- a use-after-free write of the
    sk_lock spinlock.

    tipc_release() already guards this exact failed accept() releases a
    pre-allocated child case with if (sk == NULL) return 0;, but the
    guard is bypassed because tipc_sk_create() left sock->sk non-NULL
    (dangling) rather than NULL.

    Clear sock->sk on the failed-insert path so the existing tipc_release()
    NULL check fires and the use-after-free is avoided.

    The tipc_sk_insert() failure is reached when the per-netns socket
    rhashtable hits its max_size (tsk_rht_params.max_size = 1048576, ~2M
    elements) -- i.e. once a netns holds ~2M TIPC sockets every insert
    returns -E2BIG.

      BUG: KASAN: slab-use-after-free in lock_sock_nested (net/core/sock.c:3839)
      Write of size 8 at addr ffff8880047cdc38 by task init/1
       lock_sock_nested (net/core/sock.c:3839)
       tipc_release (net/tipc/socket.c:638)
       __sock_release (net/socket.c:710)
       sock_close (net/socket.c:1501)
       __fput (fs/file_table.c:512)
      Allocated by task 1:
       sk_alloc (net/core/sock.c:2308)
       tipc_sk_create (net/tipc/socket.c:487)
       tipc_accept (net/tipc/socket.c:2744)
       do_accept (net/socket.c:2034)
      Freed by task 1:
       __sk_destruct (net/core/sock.c:2391)
       tipc_sk_create (net/tipc/socket.c:504)
       tipc_accept (net/tipc/socket.c:2744)
       do_accept (net/socket.c:2034)

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-2026-143076
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?c53dc60b");
  # https://lore.kernel.org/linux-cve-announce/2026081055-CVE-2026-68117-dd27@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?8a5ce497");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2026-68117");
  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-2026-68117");

  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:"2026/08/10");
  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');
}