Unity Linux 20.1070e Security Update: kernel (UTSA-2025-990764)

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

include('compat.inc');

if (description)
{
  script_id(275038);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/12");

  script_cve_id("CVE-2022-49872");

  script_name(english:"Unity Linux 20.1070e Security Update: kernel (UTSA-2025-990764)");

  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-2025-990764 advisory.

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

    net: gso: fix panic on frag_list with mixed head alloc types

    Since commit 3dcbdb134f32 (net: gso: Fix skb_segment splat when
    splitting gso_size mangled skb having linear-headed frag_list), it is
    allowed to change gso_size of a GRO packet. However, that commit assumes
    that checking the first list_skb member suffices; i.e if either of the
    list_skb members have non head_frag head, then the first one has too.

    It turns out this assumption does not hold. We've seen BUG_ON being hit
    in skb_segment when skbs on the frag_list had differing head_frag with
    the vmxnet3 driver. This happens because __netdev_alloc_skb and
    __napi_alloc_skb can return a skb that is page backed or kmalloced
    depending on the requested size. As the result, the last small skb in
    the GRO packet can be kmalloced.

    There are three different locations where this can be fixed:

    (1) We could check head_frag in GRO and not allow GROing skbs with
        different head_frag. However, that would lead to performance
        regression on normal forward paths with unmodified gso_size, where
        !head_frag in the last packet is not a problem.

    (2) Set a flag in bpf_skb_net_grow and bpf_skb_net_shrink indicating
        that NETIF_F_SG is undesirable. That would need to eat a bit in
        sk_buff. Furthermore, that flag can be unset when all skbs on the
        frag_list are page backed. To retain good performance,
        bpf_skb_net_grow/shrink would have to walk the frag_list.

    (3) Walk the frag_list in skb_segment when determining whether
        NETIF_F_SG should be cleared. This of course slows things down.

    This patch implements (3). To limit the performance impact in
    skb_segment, the list is walked only for skbs with SKB_GSO_DODGY set
    that have gso_size changed. Normal paths thus will not hit it.

    We could check only the last skb but since we need to walk the whole
    list anyway, let's stay on the safe side.

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-2025-990764
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?ad208dc5");
  # https://lore.kernel.org/linux-cve-announce/2025050151-CVE-2022-49872-0c67@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7435034b");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2022-49872");
  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-2022-49872");

  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:"2022/12/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/11/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/11/12");

  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) 2025 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:"^20.1070e([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 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 && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1070e',
    'pkgs': [
      {'reference':'kernel-5.10.0-79.4.2', 'sp':'1070e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.4.2', 'sp':'1070e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.4.2', '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');
}