Unity Linux 20.1070a Security Update: kernel (UTSA-2026-005657)

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

include('compat.inc');

if (description)
{
  script_id(300779);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/03/05");

  script_cve_id("CVE-2023-53354");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2026-005657)");

  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-2026-005657 advisory.

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

    skbuff: skb_segment, Call zero copy functions before using skbuff frags

    Commit bf5c25d60861 (skbuff: in skb_segment, call zerocopy functions
    once per nskb) added the call to zero copy functions in skb_segment().
    The change introduced a bug in skb_segment() because skb_orphan_frags()
    may possibly change the number of fragments or allocate new fragments
    altogether leaving nrfrags and frag to point to the old values. This can
    cause a panic with stacktrace like the one below.

    [  193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc
    [  193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G           O      5.15.123+
    #26
    [  193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0
    [  194.021892] Call Trace:
    [  194.027422]  <TASK>
    [  194.072861]  tcp_gso_segment+0x107/0x540
    [  194.082031]  inet_gso_segment+0x15c/0x3d0
    [  194.090783]  skb_mac_gso_segment+0x9f/0x110
    [  194.095016]  __skb_gso_segment+0xc1/0x190
    [  194.103131]  netem_enqueue+0x290/0xb10 [sch_netem]
    [  194.107071]  dev_qdisc_enqueue+0x16/0x70
    [  194.110884]  __dev_queue_xmit+0x63b/0xb30
    [  194.121670]  bond_start_xmit+0x159/0x380 [bonding]
    [  194.128506]  dev_hard_start_xmit+0xc3/0x1e0
    [  194.131787]  __dev_queue_xmit+0x8a0/0xb30
    [  194.138225]  macvlan_start_xmit+0x4f/0x100 [macvlan]
    [  194.141477]  dev_hard_start_xmit+0xc3/0x1e0
    [  194.144622]  sch_direct_xmit+0xe3/0x280
    [  194.147748]  __dev_queue_xmit+0x54a/0xb30
    [  194.154131]  tap_get_user+0x2a8/0x9c0 [tap]
    [  194.157358]  tap_sendmsg+0x52/0x8e0 [tap]
    [  194.167049]  handle_tx_zerocopy+0x14e/0x4c0 [vhost_net]
    [  194.173631]  handle_tx+0xcd/0xe0 [vhost_net]
    [  194.176959]  vhost_worker+0x76/0xb0 [vhost]
    [  194.183667]  kthread+0x118/0x140
    [  194.190358]  ret_from_fork+0x1f/0x30
    [  194.193670]  </TASK>

    In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags
    local variable in skb_segment() stale. This resulted in the code hitting
    i >= nrfrags prematurely and trying to move to next frag_skb using
    list_skb pointer, which was NULL, and caused kernel panic. Move the call
    to zero copy functions before using frags and nr_frags.

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-2026-005657
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?588ccdbe");
  # https://lore.kernel.org/linux-cve-announce/2025091721-CVE-2023-53354-771f@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?ebef1e6f");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2023-53354");
  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-2023-53354");

  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:"2021/07/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/03/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/03/05");

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


var constraints = [
  {
    'release': '20',
    'sp': '1070a',
    'pkgs': [
      {'reference':'kernel-5.10.0-79.7', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.7', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.7', '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_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');
}