Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986807)

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

include('compat.inc');

if (description)
{
  script_id(268175);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/10/15");

  script_cve_id("CVE-2023-52894");

  script_name(english:"Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986807)");

  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-2025-986807 advisory.

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

    usb: gadget: f_ncm: fix potential NULL ptr deref in ncm_bitrate()

    In Google internal bug 265639009 we've received an (as yet) unreproducible
    crash report from an aarch64 GKI 5.10.149-android13 running device.

    AFAICT the source code is at:
      https://android.googlesource.com/kernel/common/+/refs/tags/ASB-2022-12-05_13-5.10

    The call stack is:
      ncm_close() -> ncm_notify() -> ncm_do_notify()
    with the crash at:
      ncm_do_notify+0x98/0x270
    Code: 79000d0b b9000a6c f940012a f9400269 (b9405d4b)

    Which I believe disassembles to (I don't know ARM assembly, but it looks sane enough to me...):

      // halfword (16-bit) store presumably to event->wLength (at offset 6 of struct usb_cdc_notification)
      0B 0D 00 79    strh w11, [x8, #6]

      // word (32-bit) store presumably to req->Length (at offset 8 of struct usb_request)
      6C 0A 00 B9    str  w12, [x19, #8]

      // x10 (NULL) was read here from offset 0 of valid pointer x9
      // IMHO we're reading 'cdev->gadget' and getting NULL
      // gadget is indeed at offset 0 of struct usb_composite_dev
      2A 01 40 F9    ldr  x10, [x9]

      // loading req->buf pointer, which is at offset 0 of struct usb_request
      69 02 40 F9    ldr  x9, [x19]

      // x10 is null, crash, appears to be attempt to read cdev->gadget->max_speed
      4B 5D 40 B9    ldr  w11, [x10, #0x5c]

    which seems to line up with ncm_do_notify() case NCM_NOTIFY_SPEED code fragment:

      event->wLength = cpu_to_le16(8);
      req->length = NCM_STATUS_BYTECOUNT;

      /* SPEED_CHANGE data is up/down speeds in bits/sec */
      data = req->buf + sizeof *event;
      data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));

    My analysis of registers and NULL ptr deref crash offset
      (Unable to handle kernel NULL pointer dereference at virtual address 000000000000005c)
    heavily suggests that the crash is due to 'cdev->gadget' being NULL when executing:
      data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
    which calls:
      ncm_bitrate(NULL)
    which then calls:
      gadget_is_superspeed(NULL)
    which reads
      ((struct usb_gadget *)NULL)->max_speed
    and hits a panic.

    AFAICT, if I'm counting right, the offset of max_speed is indeed 0x5C.
    (remember there's a GKI KABI reservation of 16 bytes in struct work_struct)

    It's not at all clear to me how this is all supposed to work...
    but returning 0 seems much better than panic-ing...

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-2025-986807
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?6e3d43c9");
  # https://lore.kernel.org/linux-cve-announce/2024082111-CVE-2023-52894-c8ee@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?daec8255");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2023-52894");
  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-2023-52894");

  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:"2024/08/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/09/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/10/07");

  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-5.10.0-74.16', 'sp':'1070e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-74.16', 'sp':'1070e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-74.16', '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');
}