Unity Linux 20.1070e Security Update: kernel (UTSA-2026-013368)

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

include('compat.inc');

if (description)
{
  script_id(308141);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/21");

  script_cve_id("CVE-2023-53668");

  script_name(english:"Unity Linux 20.1070e Security Update: kernel (UTSA-2026-013368)");

  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-2026-013368 advisory.

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

    ring-buffer: Fix deadloop issue on reading trace_pipe

    Soft lockup occurs when reading file 'trace_pipe':

      watchdog: BUG: soft lockup - CPU#6 stuck for 22s! [cat:4488]
      [...]
      RIP: 0010:ring_buffer_empty_cpu+0xed/0x170
      RSP: 0018:ffff88810dd6fc48 EFLAGS: 00000246
      RAX: 0000000000000000 RBX: 0000000000000246 RCX: ffffffff93d1aaeb
      RDX: ffff88810a280040 RSI: 0000000000000008 RDI: ffff88811164b218
      RBP: ffff88811164b218 R08: 0000000000000000 R09: ffff88815156600f
      R10: ffffed102a2acc01 R11: 0000000000000001 R12: 0000000051651901
      R13: 0000000000000000 R14: ffff888115e49500 R15: 0000000000000000
      [...]
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 00007f8d853c2000 CR3: 000000010dcd8000 CR4: 00000000000006e0
      DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      Call Trace:
       __find_next_entry+0x1a8/0x4b0
       ? peek_next_entry+0x250/0x250
       ? down_write+0xa5/0x120
       ? down_write_killable+0x130/0x130
       trace_find_next_entry_inc+0x3b/0x1d0
       tracing_read_pipe+0x423/0xae0
       ? tracing_splice_read_pipe+0xcb0/0xcb0
       vfs_read+0x16b/0x490
       ksys_read+0x105/0x210
       ? __ia32_sys_pwrite64+0x200/0x200
       ? switch_fpu_return+0x108/0x220
       do_syscall_64+0x33/0x40
       entry_SYSCALL_64_after_hwframe+0x61/0xc6

    Through the vmcore, I found it's because in tracing_read_pipe(),
    ring_buffer_empty_cpu() found some buffer is not empty but then it
    cannot read anything due to rb_num_of_entries() == 0 always true,
    Then it infinitely loop the procedure due to user buffer not been
    filled, see following code path:

      tracing_read_pipe() {
        ... ...
        waitagain:
          tracing_wait_pipe() // 1. find non-empty buffer here
          trace_find_next_entry_inc()  // 2. loop here try to find an entry
            __find_next_entry()
              ring_buffer_empty_cpu();  // 3. find non-empty buffer
              peek_next_entry()  // 4. but peek always return NULL
                ring_buffer_peek()
                  rb_buffer_peek()
                    rb_get_reader_page()
                      // 5. because rb_num_of_entries() == 0 always true here
                      //    then return NULL
          // 6. user buffer not been filled so goto 'waitgain'
          //    and eventually leads to an deadloop in kernel!!!
      }

    By some analyzing, I found that when resetting ringbuffer, the 'entries'
    of its pages are not all cleared (see rb_reset_cpu()). Then when reducing
    the ringbuffer, and if some reduced pages exist dirty 'entries' data, they
    will be added into 'cpu_buffer->overrun' (see rb_remove_pages()), which
    cause wrong 'overrun' count and eventually cause the deadloop issue.

    To fix it, we need to clear every pages in rb_reset_cpu().

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-2026-013368
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?6c1b5891");
  # https://lore.kernel.org/linux-cve-announce/2025100705-CVE-2023-53668-b06b@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0ea0e44d");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2023-53668");
  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: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:H/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-2023-53668");

  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:"2026/04/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/04/21");

  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:"^20.1070e([^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 && 'sw_64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1070e',
    'pkgs': [
      {'reference':'kernel-4.19.90-2308.1.0', 'sp':'1070e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2308.1.0', 'sp':'1070e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2308.1.0', 'sp':'1070e', 'cpu':'sw_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2308.1.0', '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');
}