Unity Linux 20.1020e / 20.1050e / 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-142497)

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

include('compat.inc');

if (description)
{
  script_id(370752);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/22");

  script_cve_id("CVE-2026-74388");

  script_name(english:"Unity Linux 20.1020e / 20.1050e / 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-142497)");

  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-2026-142497 advisory.

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

    ALSA: seq: oss: Fix UAF at handling events with embedded SysEx data

    The OSS sequencer processes the input MIDI bytes into a sequencer
    event to be dispatched later (in snd_seq_oss_midi_putc() called from
    snd_seq_oss_process_event()).  When it's a SysEx data, the event
    record contains data.ext.ptr pointer to the original SysEx bytes, and
    the referred data is copied into the pool afterwards at dispatching.
    The problem is that, if the sequencer port gets closed concurrently
    before the dispatch, the OSS sequencer core also releases the
    resources (in snd_seq_oss_midi_check_exit_port()), while the pending
    event may hold a stale pointer, eventually leading to a UAF at a later
    dispatch.

    Fortunately, there is already a refcounting mechanism (snd_use_lock_t)
    for the OSS MIDI device access, and for addressing the issue above, we
    just need to extend the refcount until the event gets dispatched.

    This patch extends snd_seq_oss_process_event() to give back the
    refcount object, which is in turn released after calling the sequencer
    dispatcher with the given event in the caller side.

    According to the original report, KASAN report as below:

    KASAN slab-use-after-free in snd_seq_event_dup+0x40c/0x470
    RIP: 0033:0x7f2cb66a6340
    Read of size 6
    Call trace:
      dump_stack_lvl+0x73/0xb0 (?:?)
      print_report+0xd1/0x650 (?:?)
      srso_alias_return_thunk+0x5/0xfbef5 (?:?)
      __virt_addr_valid+0x1a7/0x340 (?:?)
      kasan_complete_mode_report_info+0x64/0x200 (?:?)
      kasan_report+0xf7/0x130 (?:?)
      snd_seq_event_dup+0x40c/0x470 (?:?)
      kasan_check_range+0x10c/0x1c0 (?:?)
      __asan_memcpy+0x27/0x70 (?:?)
      snd_seq_event_dup+0x9/0x470 (?:?)
      snd_seq_client_enqueue_event+0x139/0x240 (?:?)
      _raw_spin_unlock_irqrestore+0x4b/0x60 (?:?)
      snd_seq_kernel_client_enqueue+0x102/0x120 (?:?)
      snd_seq_oss_write+0x416/0x4e0 (?:?)
      apparmor_file_permission+0x20/0x30 (?:?)
      odev_write+0x3b/0x60 (?:?)
      vfs_write+0x1ce/0x850 (?:?)
      lock_release+0xc8/0x2a0 (?:?)
      __kasan_check_write+0x18/0x20 (?:?)
      __mutex_unlock_slowpath+0x129/0x510 (?:?)
      ksys_write+0xe1/0x180 (?:?)
      mutex_unlock+0x16/0x20 (?:?)
      odev_ioctl+0x65/0xc0 (?:?)
      __x64_sys_write+0x46/0x60 (?:?)
      x64_sys_call+0x7d/0x20d0 (?:?)
      do_syscall_64+0xc1/0x360 (arch/x86/entry/syscall_64.c:87)
      entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)

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-2026-142497
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?bd1a33a3");
  script_set_attribute(attribute:"see_also", value:"https://atomgit.com/src-openeuler/kernel/issues/18134");
  # https://lore.kernel.org/linux-cve-announce/2026081506-CVE-2026-74388-e1a2@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?6818b1f1");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2026-74388");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:C/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:H/I:H/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-2026-74388");

  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:"2026/08/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/22");

  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:"^(20.1020e|20.1050e|20.1060e|20.1070e)([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1020e / 20.1050e / 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': '1020e',
    'pkgs': [
      {'reference':'kernel-4.19.90-2211.5.0.0178.68.uel20', 'sp':'1020e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2211.5.0.0178.68.uel20', 'sp':'1020e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2211.5.0.0178.68.uel20', 'sp':'1020e', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  },
  {
    'release': '20',
    'sp': '1050e',
    'pkgs': [
      {'reference':'kernel-4.19.90-2305.1.0.0199.123.uel20', 'sp':'1050e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2305.1.0.0199.123.uel20', 'sp':'1050e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2305.1.0.0199.123.uel20', 'sp':'1050e', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  },
  {
    'release': '20',
    'sp': '1060e',
    'pkgs': [
      {'reference':'kernel-4.19.90-2311.4.0.0227.123.uel20', 'sp':'1060e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2311.4.0.0227.123.uel20', 'sp':'1060e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2311.4.0.0227.123.uel20', 'sp':'1060e', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  },
  {
    'release': '20',
    'sp': '1070e',
    'pkgs': [
      {'reference':'kernel-4.19.90-2601.1.0.0024.uel20', 'sp':'1070e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2601.1.0.0024.uel20', 'sp':'1070e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2601.1.0.0024.uel20', 'sp':'1070e', 'cpu':'sw_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2601.1.0.0024.uel20', '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');
}