Unity Linux 20.1050e Security Update: kernel (UTSA-2026-099711)

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

include('compat.inc');

if (description)
{
  script_id(336895);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/17");

  script_cve_id("CVE-2026-31494");

  script_name(english:"Unity Linux 20.1050e Security Update: kernel (UTSA-2026-099711)");

  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-2026-099711 advisory.

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

    net: macb: use the current queue number for stats

    There's a potential mismatch between the memory reserved for statistics
    and the amount of memory written.

    gem_get_sset_count() correctly computes the number of stats based on the
    active queues, whereas gem_get_ethtool_stats() indiscriminately copies
    data using the maximum number of queues, and in the case the number of
    active queues is less than MACB_MAX_QUEUES, this results in a OOB write
    as observed in the KASAN splat.

    ==================================================================
    BUG: KASAN: vmalloc-out-of-bounds in gem_get_ethtool_stats+0x54/0x78
      [macb]
    Write of size 760 at addr ffff80008080b000 by task ethtool/1027

    CPU: [...]
    Tainted: [E]=UNSIGNED_MODULE
    Hardware name: raspberrypi rpi/rpi, BIOS 2025.10 10/01/2025
    Call trace:
     show_stack+0x20/0x38 (C)
     dump_stack_lvl+0x80/0xf8
     print_report+0x384/0x5e0
     kasan_report+0xa0/0xf0
     kasan_check_range+0xe8/0x190
     __asan_memcpy+0x54/0x98
     gem_get_ethtool_stats+0x54/0x78 [macb
       926c13f3af83b0c6fe64badb21ec87d5e93fcf65]
     dev_ethtool+0x1220/0x38c0
     dev_ioctl+0x4ac/0xca8
     sock_do_ioctl+0x170/0x1d8
     sock_ioctl+0x484/0x5d8
     __arm64_sys_ioctl+0x12c/0x1b8
     invoke_syscall+0xd4/0x258
     el0_svc_common.constprop.0+0xb4/0x240
     do_el0_svc+0x48/0x68
     el0_svc+0x40/0xf8
     el0t_64_sync_handler+0xa0/0xe8
     el0t_64_sync+0x1b0/0x1b8

    The buggy address belongs to a 1-page vmalloc region starting at
      0xffff80008080b000 allocated at dev_ethtool+0x11f0/0x38c0
    The buggy address belongs to the physical page:
    page: refcount:1 mapcount:0 mapping:0000000000000000
      index:0xffff00000a333000 pfn:0xa333
    flags: 0x7fffc000000000(node=0|zone=0|lastcpupid=0x1ffff)
    raw: 007fffc000000000 0000000000000000 dead000000000122 0000000000000000
    raw: ffff00000a333000 0000000000000000 00000001ffffffff 0000000000000000
    page dumped because: kasan: bad access detected

    Memory state around the buggy address:
     ffff80008080b080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     ffff80008080b100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    >ffff80008080b180: 00 00 00 00 00 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                                      ^
     ffff80008080b200: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
     ffff80008080b280: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
    ==================================================================

    Fix it by making sure the copied size only considers the active number of
    queues.

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-2026-099711
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?5e787ee0");
  # https://lore.kernel.org/linux-cve-announce/2026042202-CVE-2026-31494-647e@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0fd9596a");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2026-31494");
  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-2026-31494");

  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:"2026/04/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/17");

  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-5.10.0-27.18.uel20', 'sp':'1050e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-27.18.uel20', 'sp':'1050e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-27.18.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');
}