Unity Linux 20.1070a Security Update: kernel (UTSA-2025-986322)

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

include('compat.inc');

if (description)
{
  script_id(268494);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/10/15");

  script_cve_id("CVE-2021-47274");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2025-986322)");

  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-2025-986322 advisory.

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

    tracing: Correct the length check which causes memory corruption

    We've suffered from severe kernel crashes due to memory corruption on
    our production environment, like,

    Call Trace:
    [1640542.554277] general protection fault: 0000 [#1] SMP PTI
    [1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: loaded Tainted:G
    [1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190
    [1640542.559074] RSP: 0018:ffffb16faa597df8 EFLAGS: 00010286
    [1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX:
    0000000006e931bf
    [1640542.560323] RDX: 0000000006e931be RSI: 0000000000400200 RDI:
    ffff9a45ff004300
    [1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09:
    0000000000000000
    [1640542.561670] R10: 0000000000000000 R11: 0000000000000000 R12:
    ffffffff9a20608d
    [1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15:
    696c662f65636976
    [1640542.563128] FS:  00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000)
    knlGS:0000000000000000
    [1640542.563937] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    [1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4:
    00000000003606e0
    [1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
    0000000000000000
    [1640542.566069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
    0000000000000400
    [1640542.566742] Call Trace:
    [1640542.567009]  anon_vma_clone+0x5d/0x170
    [1640542.567417]  __split_vma+0x91/0x1a0
    [1640542.567777]  do_munmap+0x2c6/0x320
    [1640542.568128]  vm_munmap+0x54/0x70
    [1640542.569990]  __x64_sys_munmap+0x22/0x30
    [1640542.572005]  do_syscall_64+0x5b/0x1b0
    [1640542.573724]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
    [1640542.575642] RIP: 0033:0x7f45d6e61e27

    James Wang has reproduced it stably on the latest 4.19 LTS.
    After some debugging, we finally proved that it's due to ftrace
    buffer out-of-bound access using a debug tool as follows:
    [   86.775200] BUG: Out-of-bounds write at addr 0xffff88aefe8b7000
    [   86.780806]  no_context+0xdf/0x3c0
    [   86.784327]  __do_page_fault+0x252/0x470
    [   86.788367]  do_page_fault+0x32/0x140
    [   86.792145]  page_fault+0x1e/0x30
    [   86.795576]  strncpy_from_unsafe+0x66/0xb0
    [   86.799789]  fetch_memory_string+0x25/0x40
    [   86.804002]  fetch_deref_string+0x51/0x60
    [   86.808134]  kprobe_trace_func+0x32d/0x3a0
    [   86.812347]  kprobe_dispatcher+0x45/0x50
    [   86.816385]  kprobe_ftrace_handler+0x90/0xf0
    [   86.820779]  ftrace_ops_assist_func+0xa1/0x140
    [   86.825340]  0xffffffffc00750bf
    [   86.828603]  do_sys_open+0x5/0x1f0
    [   86.832124]  do_syscall_64+0x5b/0x1b0
    [   86.835900]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

    commit b220c049d519 (tracing: Check length before giving out
    the filter buffer) adds length check to protect trace data
    overflow introduced in 0fc1b09ff1ff, seems that this fix can't prevent
    overflow entirely, the length check should also take the sizeof
    entry->array[0] into account, since this array[0] is filled the
    length of trace data and occupy addtional space and risk overflow.

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-2025-986322
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7322a066");
  # https://lore.kernel.org/linux-cve-announce/2024052151-CVE-2021-47274-3867@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?5979a0f4");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2021-47274");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  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:N/AC:L/PR:N/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-2021-47274");

  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:"2022/01/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/09/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/10/07");

  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) 2025 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:"^20.1070a([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1070a', '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 && 'loongarch64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1070a',
    'pkgs': [
      {'reference':'kernel-4.19.0-91.82.190.002', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.190.002', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.190.002', 'sp':'1070a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.190.002', 'sp':'1070a', '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');
}