Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986927)

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

include('compat.inc');

if (description)
{
  script_id(268508);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/10/15");

  script_cve_id("CVE-2022-48869");

  script_name(english:"Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986927)");

  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-2025-986927 advisory.

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

    USB: gadgetfs: Fix race between mounting and unmounting

    The syzbot fuzzer and Gerald Lee have identified a use-after-free bug
    in the gadgetfs driver, involving processes concurrently mounting and
    unmounting the gadgetfs filesystem.  In particular, gadgetfs_fill_super()
    can race with gadgetfs_kill_sb(), causing the latter to deallocate
    the_device while the former is using it.  The output from KASAN says,
    in part:

    BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
    BUG: KASAN: use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176
    [inline]
    BUG: KASAN: use-after-free in __refcount_sub_and_test include/linux/refcount.h:272 [inline]
    BUG: KASAN: use-after-free in __refcount_dec_and_test include/linux/refcount.h:315 [inline]
    BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:333 [inline]
    BUG: KASAN: use-after-free in put_dev drivers/usb/gadget/legacy/inode.c:159 [inline]
    BUG: KASAN: use-after-free in gadgetfs_kill_sb+0x33/0x100 drivers/usb/gadget/legacy/inode.c:2086
    Write of size 4 at addr ffff8880276d7840 by task syz-executor126/18689

    CPU: 0 PID: 18689 Comm: syz-executor126 Not tainted 6.1.0-syzkaller #0
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
    Call Trace:
     <TASK>
    ...
     atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline]
     __refcount_sub_and_test include/linux/refcount.h:272 [inline]
     __refcount_dec_and_test include/linux/refcount.h:315 [inline]
     refcount_dec_and_test include/linux/refcount.h:333 [inline]
     put_dev drivers/usb/gadget/legacy/inode.c:159 [inline]
     gadgetfs_kill_sb+0x33/0x100 drivers/usb/gadget/legacy/inode.c:2086
     deactivate_locked_super+0xa7/0xf0 fs/super.c:332
     vfs_get_super fs/super.c:1190 [inline]
     get_tree_single+0xd0/0x160 fs/super.c:1207
     vfs_get_tree+0x88/0x270 fs/super.c:1531
     vfs_fsconfig_locked fs/fsopen.c:232 [inline]

    The simplest solution is to ensure that gadgetfs_fill_super() and
    gadgetfs_kill_sb() are serialized by making them both acquire a new
    mutex.

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-2025-986927
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?84e56031");
  # https://lore.kernel.org/linux-cve-announce/2024082105-CVE-2022-48869-bfe9@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9fa4d9fb");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2022-48869");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/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:H/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-2022-48869");

  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_NOTE,
      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');
}