Unity Linux 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-011071)

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

include('compat.inc');

if (description)
{
  script_id(308916);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/21");

  script_cve_id("CVE-2023-53809");

  script_name(english:"Unity Linux 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-011071)");

  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-2026-011071 advisory.

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

    l2tp: Avoid possible recursive deadlock in l2tp_tunnel_register()

    When a file descriptor of pppol2tp socket is passed as file descriptor
    of UDP socket, a recursive deadlock occurs in l2tp_tunnel_register().
    This situation is reproduced by the following program:

    int main(void)
    {
            int sock;
            struct sockaddr_pppol2tp addr;

            sock = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
            if (sock < 0) {
                    perror(socket);
                    return 1;
            }

            addr.sa_family = AF_PPPOX;
            addr.sa_protocol = PX_PROTO_OL2TP;
            addr.pppol2tp.pid = 0;
            addr.pppol2tp.fd = sock;
            addr.pppol2tp.addr.sin_family = PF_INET;
            addr.pppol2tp.addr.sin_port = htons(0);
            addr.pppol2tp.addr.sin_addr.s_addr = inet_addr(192.168.0.1);
            addr.pppol2tp.s_tunnel = 1;
            addr.pppol2tp.s_session = 0;
            addr.pppol2tp.d_tunnel = 0;
            addr.pppol2tp.d_session = 0;

            if (connect(sock, (const struct sockaddr *)&addr, sizeof(addr)) < 0) {
                    perror(connect);
                    return 1;
            }

            return 0;
    }

    This program causes the following lockdep warning:

     ============================================
     WARNING: possible recursive locking detected
     6.2.0-rc5-00205-gc96618275234 #56 Not tainted
     --------------------------------------------
     repro/8607 is trying to acquire lock:
     ffff8880213c8130 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: l2tp_tunnel_register+0x2b7/0x11c0

     but task is already holding lock:
     ffff8880213c8130 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pppol2tp_connect+0xa82/0x1a30

     other info that might help us debug this:
      Possible unsafe locking scenario:

            CPU0
            ----
       lock(sk_lock-AF_PPPOX);
       lock(sk_lock-AF_PPPOX);

      *** DEADLOCK ***

      May be due to missing lock nesting notation

     1 lock held by repro/8607:
      #0: ffff8880213c8130 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pppol2tp_connect+0xa82/0x1a30

     stack backtrace:
     CPU: 0 PID: 8607 Comm: repro Not tainted 6.2.0-rc5-00205-gc96618275234 #56
     Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014
     Call Trace:
      <TASK>
      dump_stack_lvl+0x100/0x178
      __lock_acquire.cold+0x119/0x3b9
      ? lockdep_hardirqs_on_prepare+0x410/0x410
      lock_acquire+0x1e0/0x610
      ? l2tp_tunnel_register+0x2b7/0x11c0
      ? lock_downgrade+0x710/0x710
      ? __fget_files+0x283/0x3e0
      lock_sock_nested+0x3a/0xf0
      ? l2tp_tunnel_register+0x2b7/0x11c0
      l2tp_tunnel_register+0x2b7/0x11c0
      ? sprintf+0xc4/0x100
      ? l2tp_tunnel_del_work+0x6b0/0x6b0
      ? debug_object_deactivate+0x320/0x320
      ? lockdep_init_map_type+0x16d/0x7a0
      ? lockdep_init_map_type+0x16d/0x7a0
      ? l2tp_tunnel_create+0x2bf/0x4b0
      ? l2tp_tunnel_create+0x3c6/0x4b0
      pppol2tp_connect+0x14e1/0x1a30
      ? pppol2tp_put_sk+0xd0/0xd0
      ? aa_sk_perm+0x2b7/0xa80
      ? aa_af_perm+0x260/0x260
      ? bpf_lsm_socket_connect+0x9/0x10
      ? pppol2tp_put_sk+0xd0/0xd0
      __sys_connect_file+0x14f/0x190
      __sys_connect+0x133/0x160
      ? __sys_connect_file+0x190/0x190
      ? lockdep_hardirqs_on+0x7d/0x100
      ? ktime_get_coarse_real_ts64+0x1b7/0x200
      ? ktime_get_coarse_real_ts64+0x147/0x200
      ? __audit_syscall_entry+0x396/0x500
      __x64_sys_connect+0x72/0xb0
      do_syscall_64+0x38/0xb0
      entry_SYSCALL_64_after_hwframe+0x63/0xcd

    This patch fixes the issue by getting/creating the tunnel before
    locking the pppol2tp socket.

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-2026-011071
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?49dd8644");
  # https://lore.kernel.org/linux-cve-announce/2025120944-CVE-2023-53809-ca78@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?229af6fe");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2023-53809");
  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-2023-53809");

  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:"2023/03/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/04/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/04/21");

  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:"^20.1060e|20.1070e([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1060e / 20.1070e', '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 && 'sw_64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1060e',
    'pkgs': [
      {'reference':'kernel-5.10.0-38', 'sp':'1060e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-38', 'sp':'1060e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-38', 'sp':'1060e', 'cpu':'sw_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-38', 'sp':'1060e', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  },
  {
    'release': '20',
    'sp': '1070e',
    'pkgs': [
      {'reference':'kernel-5.10.0-38', 'sp':'1070e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-38', 'sp':'1070e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-38', 'sp':'1070e', 'cpu':'sw_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-38', 'sp':'1070e', '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');
}