Unity Linux 20.1050e Security Update: kernel (UTSA-2026-101967)

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

include('compat.inc');

if (description)
{
  script_id(337275);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/18");

  script_cve_id("CVE-2026-64546");

  script_name(english:"Unity Linux 20.1050e Security Update: kernel (UTSA-2026-101967)");

  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-2026-101967 advisory.

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

    drm/edid: fix OOB read in drm_parse_tiled_block()

    drm_parse_tiled_block() casts the DisplayID block to a
    struct displayid_tiled_block and reads the full fixed layout up to
    tile->topology_id[7] without checking block->num_bytes. The DisplayID
    iterator only validates the declared payload length, so a crafted EDID
    can advertise a tiled-display block (tag DATA_BLOCK_TILED_DISPLAY, or
    DATA_BLOCK_2_TILED_DISPLAY_TOPOLOGY for v2.0) with a small num_bytes at
    the end of a DisplayID extension. The read then runs past the end of the
    exact-sized kmemdup()'d EDID allocation, a heap out-of-bounds read.

    Reject blocks shorter than the spec's 22-byte tiled payload before
    reading the fixed struct, as drm_parse_vesa_mso_data() already does.

      BUG: KASAN: slab-out-of-bounds in drm_edid_connector_update
      Read of size 2 at addr ffff888010077700 by task exploit/147
       dump_stack_lvl (lib/dump_stack.c:94 ...)
       print_report (mm/kasan/report.c:378 ...)
       kasan_report (mm/kasan/report.c:595)
       drm_edid_connector_update (drivers/gpu/drm/drm_edid.c:7581)
       bochs_connector_helper_get_modes (drivers/gpu/drm/tiny/bochs.c:574)
       drm_helper_probe_single_connector_modes (drivers/gpu/drm/drm_probe_helper.c:426)
       status_store (drivers/gpu/drm/drm_sysfs.c:219)
       ...
       vfs_write (fs/read_write.c:595 fs/read_write.c:688)
       ksys_write (fs/read_write.c:740)

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-2026-101967
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?e86ced77");
  # https://lore.kernel.org/linux-cve-announce/2026072736-CVE-2026-64546-44ba@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?673ac0e7");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2026-64546");
  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-2026-64546");

  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:"2026/07/27");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/18");

  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:"^20.1050e([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1050e', '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': '1050e',
    'pkgs': [
      {'reference':'kernel-4.19.90-2211.5.0.0178.67.uel20', 'sp':'1050e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2211.5.0.0178.67.uel20', 'sp':'1050e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2211.5.0.0178.67.uel20', 'sp':'1050e', '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');
}