TencentOS Server 3: kernel (TSSA-2026:1026)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2026:1026.
##

include('compat.inc');

if (description)
{
  script_id(348667);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/21");

  script_cve_id("CVE-2026-74580");

  script_name(english:"TencentOS Server 3: kernel (TSSA-2026:1026)");

  script_set_attribute(attribute:"synopsis", value:
"The remote TencentOS Server 3 host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The version of Tencent Linux installed on the remote TencentOS Server 3 host is prior to tested version. It is,
therefore, affected by a vulnerability as referenced in the TSSA-2026:1026 advisory.

    Package updates are available for TencentOS Server 3 that fix the following vulnerabilities:

    CVE-2026-74580:
    In the Linux kernel, the following vulnerability has been resolved:

    vhost: reset the vring metadata cache on vring reconfiguration

    vq->meta_iotlb[] caches the vhost_iotlb_map that backs each vring
    metadata region, and iotlb_access_ok() returns early on a cache hit,
    taking the hit as proof that the region has already been validated:

            if (vhost_vq_meta_fetch(vq, addr, len, type))
                    return true;

    The cache is reset on VHOST_IOTLB_UPDATE and VHOST_IOTLB_INVALIDATE, on
    device IOTLB (re)initialisation and on vq reset, but not when
    VHOST_SET_VRING_ADDR replaces vq->desc, vq->avail and vq->used, nor when
    VHOST_SET_VRING_NUM changes the region sizes.

    With a device IOTLB attached both ioctls are accepted while the vq is
    live, and neither validates the addresses at ioctl time: vq_access_ok()
    and vq_log_used_access_ok() return true early because the addresses are
    GIOVAs, deferring validation to prefetch time.  Once the cache has been
    populated that deferred validation no longer runs -- vq_meta_prefetch()
    hits the stale entry and returns true -- and vhost_vq_meta_fetch() keeps
    translating through the old mapping as

            map->addr + addr - map->start

    for an address the mapping no longer covers.  vhost_copy_to_user() and
    vhost_copy_from_user() consume the result with __copy_to_user() and
    __copy_from_user(), which do not check it either, so a subsequent used
    ring update or descriptor fetch accesses memory outside the region the
    IOTLB actually maps.

    Reset the metadata cache whenever the vring is reconfigured, so the new
    addresses are pushed back through iotlb_access_ok()'s slow path.

Tenable has extracted the preceding description block directly from the Tencent 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.");
  script_set_attribute(attribute:"see_also", value:"https://mirrors.tencent.com/tlinux/errata/tssa-20261026.xml");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  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:C/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-2026-74580");

  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:"2026/08/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/21");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:tencent:tencentos_server:3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:tencent:tencentos_server:kernel");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Tencent 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/etc/os-release", "Host/TencentOS/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) || 'TencentOS' >!< os_product) audit(AUDIT_OS_NOT, 'TencentOS');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'TencentOS');
if (! preg(pattern:"^3([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'TencentOS 3.x', 'TencentOS ' + os_version);

if (!get_kb_item('Host/TencentOS/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$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'TencentOS', cpu);

var constraints = [
  {
    'release': '3',
    'pkgs': [
      {'reference':'bpftool-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'bpftool-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'bpftool-debuginfo-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'bpftool-debuginfo-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-core-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-core-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debuginfo-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debuginfo-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debuginfo-common-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debuginfo-common-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-devel-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-devel-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-headers-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-headers-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-modules-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-modules-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-debuginfo-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-debuginfo-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-libs-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-libs-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-libs-devel-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-libs-devel-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'mlnx-ofed-dist-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'mlnx-ofed-dist-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'perf-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'perf-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'perf-debuginfo-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'perf-debuginfo-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-perf-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-perf-5.4.241-24.0017.44.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-perf-debuginfo-5.4.241-24.0017.44.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-perf-debuginfo-5.4.241-24.0017.44.tl3', '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, 'bpftool / bpftool-debuginfo / kernel / etc');
}