Oracle Linux 7 / 8 : Unbreakable Enterprise kernel (ELSA-2026-500238)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Oracle Linux Security Advisory ELSA-2026-500238.
##

include('compat.inc');

if (description)
{
  script_id(342650);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/03");

  script_cve_id(
    "CVE-2026-31598",
    "CVE-2026-46116",
    "CVE-2026-52995",
    "CVE-2026-68480"
  );

  script_name(english:"Oracle Linux 7 / 8 : Unbreakable Enterprise kernel (ELSA-2026-500238)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 7 / 8 host has packages installed that are affected by multiple vulnerabilities as referenced in
the ELSA-2026-500238 advisory.

    - x86/bugs: Make Safe-RET robust against interrupt injection (Borislav Petkov (AMD))  [Orabug: 39784513]
    {CVE-2026-68480}
    - ocfs2: fix possible deadlock between unlink and dio_end_io_write (Joseph Qi)  [Orabug: 39273589]
    {CVE-2026-31598}
    - xfrm: defensively unhash xfrm_state lists in __xfrm_state_delete (Michal Kosiorek)  [Orabug: 39460235]
    {CVE-2026-46116}
    - net/rds: zero per-item info buffer before handing it to visitors (Michael Bommarito)  [Orabug: 39638198]
    {CVE-2026-52995}
    - xfs: resample the data fork mapping after cycling ILOCK (Darrick J. Wong)  [Orabug: 39776792]
    {CVE-2026-64600}
    - KVM: x86: Fix shadow paging use-after-free due to unexpected role (Paolo Bonzini)  [Orabug: 39673871]
    {CVE-2026-53359}
    - KVM: x86: Fix shadow paging use-after-free due to unexpected GFN (Sean Christopherson)  [Orabug:
    39673871] {CVE-2026-46113}
    - net/sched: fix pedit partial COW leading to page cache corruption (Rajat Gupta)  [Orabug: 39567287]
    {CVE-2026-46331}
    - RDMA/rxe: Validate pad and ICRC before payload_size() in rxe_rcv (hkbinbin)  [Orabug: 39452261]
    {CVE-2026-46043}
    - locking/rtmutex: Skip remove_waiter() when waiter is not enqueued (Davidlohr Bueso)  [Orabug: 39426001]
    {CVE-2026-53163}
    - rtmutex: Use waiter::task instead of current in remove_waiter() (Keenan Dong)  [Orabug: 39426001]
    {CVE-2026-43499}
    - ipv6: icmp: clear skb2->cb[] in ip6_err_gen_icmpv6_unreach() (Eric Dumazet)  [Orabug: 39300930]
    {CVE-2026-43038}
    - net: skbuff: fix missing zerocopy reference in pskb_carve helpers (Minh Nguyen)  [Orabug: 39619389]
    {CVE-2026-52943}
    - net: fix fanout UAF in packet_release() via NETDEV_UP race (Yochai Eisenrich)  [Orabug: 39250953]
    {CVE-2026-31504}
    - net: tap: NULL pointer derefence in dev_parse_header_protocol when skb->dev is null (Cezar Bulinaru)
    [Orabug: 39526882]  {CVE-2022-50073}
    - arm64: errata: Mitigate TLBI errata on various Arm CPUs (Mark Rutland)  [Orabug: 39548666]
    {CVE-2025-10263} {CVE-2026-53354}
    - ip6_tunnel: clear skb2->cb[] in ip4ip6_err() (Eric Dumazet)  [Orabug: 39300926]  {CVE-2026-43037}
    - batman-adv: hold claim backbone gateways by reference (Haoze Xie)  [Orabug: 39262375]  {CVE-2026-31657}
    - scsi: fcoe: Reject FIP descriptors with zero fip_dlen in CVL walker (Michael Bommarito)  [Orabug:
    39446045] {CVE-2026-63890}
    - scsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd() (Michael Bommarito)
    [Orabug: 39446045] {CVE-2026-63888}
    - scsi: target: iscsi: Bound iscsi_encode_text_output() appends to rsp_buf (Michael Bommarito)  [Orabug:
    39446045] {CVE-2026-63887}
    - smb: client: reject userspace cifs.spnego descriptions (Asim Viladi Oglu Manizada)  [Orabug: 39463669]
    {CVE-2026-46243}
    - tun: free page on build_skb failure in tun_xdp_one() (Weiming Shi) [Orabug: 39429147] {CVE-2026-46322}
    - tap: free page on error paths in tap_get_user_xdp() (Weiming Shi) [Orabug: 39429147] {CVE-2026-46320}

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://linux.oracle.com/errata/ELSA-2026-500238.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/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:L/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-2026-52995");

  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:"2026/04/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:8:10:baseos_patch");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-container");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-container-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-debug-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-tools");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Oracle 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("linux_alt_patch_detect.nasl", "ssh_get_info.nasl");
  script_require_keys("Host/OracleLinux", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/local_checks_enabled");

  exit(0);
}


include('rpm2.inc');
include('ksplice.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) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:os_product)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
if (! preg(pattern:"^(7|8)([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'Oracle Linux 7.x / 8.x', 'Oracle Linux ' + os_version);

if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Oracle Linux', cpu);

var machine_uptrack_level = get_one_kb_item('Host/livepatch-kernel-version');
var livepatch_source = get_one_kb_item('Host/livepatch-kernel-source');
if (empty_or_null(livepatch_source)) livepatch_source = 'KSplice';

if (machine_uptrack_level)
{
  var trimmed_uptrack_level = ereg_replace(string:machine_uptrack_level, pattern:"\.(x86_64|i[3-6]86|aarch64)$", replace:'');
  var fixed_uptrack_levels = ['5.4.17-2136.359.3.el7uek', '5.4.17-2136.359.3.el8uek'];
  foreach var fixed_uptrack_level ( fixed_uptrack_levels ) {
    if (rpm_spec_vers_cmp(a:trimmed_uptrack_level, b:fixed_uptrack_level) >= 0)
    {
      audit(AUDIT_PATCH_INSTALLED, livepatch_source + ' hotfix for ELSA-2026-500238');
    }
  }
  __rpm_report = 'Running ' + livepatch_source + ' level of ' + trimmed_uptrack_level + ' does not meet the minimum fixed level of ' + join(fixed_uptrack_levels, sep:' / ') + ' for this advisory.\n\n';
}

var kernel_major_minor = get_kb_item('Host/uname/major_minor');
if (empty_or_null(kernel_major_minor)) exit(1, 'Unable to determine kernel major-minor level.');
var expected_kernel_major_minor = '5.4';
if (kernel_major_minor != expected_kernel_major_minor)
  audit(AUDIT_OS_NOT, 'running kernel level ' + expected_kernel_major_minor + ', it is running kernel level ' + kernel_major_minor);

var constraints = [
  {
    'release': '7',
    'pkgs': [
      {'reference':'kernel-uek-5.4.17-2136.359.3.el7uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-5.4.17'},
      {'reference':'kernel-uek-container-5.4.17-2136.359.3.el7uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-container-5.4.17'},
      {'reference':'kernel-uek-container-debug-5.4.17-2136.359.3.el7uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-container-debug-5.4.17'},
      {'reference':'kernel-uek-debug-5.4.17-2136.359.3.el7uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-5.4.17'},
      {'reference':'kernel-uek-debug-devel-5.4.17-2136.359.3.el7uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-5.4.17'},
      {'reference':'kernel-uek-devel-5.4.17-2136.359.3.el7uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-5.4.17'},
      {'reference':'kernel-uek-doc-5.4.17-2136.359.3.el7uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-doc-5.4.17'},
      {'reference':'kernel-uek-tools-5.4.17-2136.359.3.el7uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-5.4.17'}
    ]
  },
  {
    'release': '8',
    'pkgs': [
      {'reference':'kernel-uek-5.4.17-2136.359.3.el8uek', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-5.4.17'},
      {'reference':'kernel-uek-debug-5.4.17-2136.359.3.el8uek', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-5.4.17'},
      {'reference':'kernel-uek-debug-devel-5.4.17-2136.359.3.el8uek', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-5.4.17'},
      {'reference':'kernel-uek-devel-5.4.17-2136.359.3.el8uek', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-5.4.17'},
      {'reference':'kernel-uek-doc-5.4.17-2136.359.3.el8uek', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-doc-5.4.17'},
      {'reference':'kernel-uek-5.4.17-2136.359.3.el8uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-5.4.17'},
      {'reference':'kernel-uek-container-5.4.17-2136.359.3.el8uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-container-5.4.17'},
      {'reference':'kernel-uek-container-debug-5.4.17-2136.359.3.el8uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-container-debug-5.4.17'},
      {'reference':'kernel-uek-debug-5.4.17-2136.359.3.el8uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-5.4.17'},
      {'reference':'kernel-uek-debug-devel-5.4.17-2136.359.3.el8uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-5.4.17'},
      {'reference':'kernel-uek-devel-5.4.17-2136.359.3.el8uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-5.4.17'},
      {'reference':'kernel-uek-doc-5.4.17-2136.359.3.el8uek', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-doc-5.4.17'}
    ]
  }
];

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-uek / kernel-uek-container / kernel-uek-container-debug / etc');
}