Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986712)

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

include('compat.inc');

if (description)
{
  script_id(268024);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/10/15");

  script_cve_id("CVE-2021-47300");

  script_name(english:"Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986712)");

  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-2025-986712 advisory.

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

    bpf: Fix tail_call_reachable rejection for interpreter when jit failed

    During testing of f263a81451c1 (bpf: Track subprog poke descriptors correctly
    and fix use-after-free) under various failure conditions, for example, when
    jit_subprogs() fails and tries to clean up the program to be run under the
    interpreter, we ran into the following freeze:

      [...]
      #127/8 tailcall_bpf2bpf_3:FAIL
      [...]
      [   92.041251] BUG: KASAN: slab-out-of-bounds in ___bpf_prog_run+0x1b9d/0x2e20
      [   92.042408] Read of size 8 at addr ffff88800da67f68 by task test_progs/682
      [   92.043707]
      [   92.044030] CPU: 1 PID: 682 Comm: test_progs Tainted: G   O   5.13.0-53301-ge6c08cb33a30-dirty #87
      [   92.045542] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
      [   92.046785] Call Trace:
      [   92.047171]  ? __bpf_prog_run_args64+0xc0/0xc0
      [   92.047773]  ? __bpf_prog_run_args32+0x8b/0xb0
      [   92.048389]  ? __bpf_prog_run_args64+0xc0/0xc0
      [   92.049019]  ? ktime_get+0x117/0x130
      [...] // few hundred [similar] lines more
      [   92.659025]  ? ktime_get+0x117/0x130
      [   92.659845]  ? __bpf_prog_run_args64+0xc0/0xc0
      [   92.660738]  ? __bpf_prog_run_args32+0x8b/0xb0
      [   92.661528]  ? __bpf_prog_run_args64+0xc0/0xc0
      [   92.662378]  ? print_usage_bug+0x50/0x50
      [   92.663221]  ? print_usage_bug+0x50/0x50
      [   92.664077]  ? bpf_ksym_find+0x9c/0xe0
      [   92.664887]  ? ktime_get+0x117/0x130
      [   92.665624]  ? kernel_text_address+0xf5/0x100
      [   92.666529]  ? __kernel_text_address+0xe/0x30
      [   92.667725]  ? unwind_get_return_address+0x2f/0x50
      [   92.668854]  ? ___bpf_prog_run+0x15d4/0x2e20
      [   92.670185]  ? ktime_get+0x117/0x130
      [   92.671130]  ? __bpf_prog_run_args64+0xc0/0xc0
      [   92.672020]  ? __bpf_prog_run_args32+0x8b/0xb0
      [   92.672860]  ? __bpf_prog_run_args64+0xc0/0xc0
      [   92.675159]  ? ktime_get+0x117/0x130
      [   92.677074]  ? lock_is_held_type+0xd5/0x130
      [   92.678662]  ? ___bpf_prog_run+0x15d4/0x2e20
      [   92.680046]  ? ktime_get+0x117/0x130
      [   92.681285]  ? __bpf_prog_run32+0x6b/0x90
      [   92.682601]  ? __bpf_prog_run64+0x90/0x90
      [   92.683636]  ? lock_downgrade+0x370/0x370
      [   92.684647]  ? mark_held_locks+0x44/0x90
      [   92.685652]  ? ktime_get+0x117/0x130
      [   92.686752]  ? lockdep_hardirqs_on+0x79/0x100
      [   92.688004]  ? ktime_get+0x117/0x130
      [   92.688573]  ? __cant_migrate+0x2b/0x80
      [   92.689192]  ? bpf_test_run+0x2f4/0x510
      [   92.689869]  ? bpf_test_timer_continue+0x1c0/0x1c0
      [   92.690856]  ? rcu_read_lock_bh_held+0x90/0x90
      [   92.691506]  ? __kasan_slab_alloc+0x61/0x80
      [   92.692128]  ? eth_type_trans+0x128/0x240
      [   92.692737]  ? __build_skb+0x46/0x50
      [   92.693252]  ? bpf_prog_test_run_skb+0x65e/0xc50
      [   92.693954]  ? bpf_prog_test_run_raw_tp+0x2d0/0x2d0
      [   92.694639]  ? __fget_light+0xa1/0x100
      [   92.695162]  ? bpf_prog_inc+0x23/0x30
      [   92.695685]  ? __sys_bpf+0xb40/0x2c80
      [   92.696324]  ? bpf_link_get_from_fd+0x90/0x90
      [   92.697150]  ? mark_held_locks+0x24/0x90
      [   92.698007]  ? lockdep_hardirqs_on_prepare+0x124/0x220
      [   92.699045]  ? finish_task_switch+0xe6/0x370
      [   92.700072]  ? lockdep_hardirqs_on+0x79/0x100
      [   92.701233]  ? finish_task_switch+0x11d/0x370
      [   92.702264]  ? __switch_to+0x2c0/0x740
      [   92.703148]  ? mark_held_locks+0x24/0x90
      [   92.704155]  ? __x64_sys_bpf+0x45/0x50
      [   92.705146]  ? do_syscall_64+0x35/0x80
      [   92.706953]  ? entry_SYSCALL_64_after_hwframe+0x44/0xae
      [...]

    Turns out that the program rejection from e411901c0b77 (bpf: allow for tailcalls
    in BPF subprograms for x64 JIT) is buggy since env->prog->aux->tail_call_reachable
    is never true. Commit ebf7d1f508a7 (bpf, x64: rework pro/epilogue and tailcall
    handling in JIT) added a tracker into check_max_stack_depth() which propagates
    the tail_call_reachable condition throughout the subprograms. This info is then
    assigned to the subprogram's
    ---truncated---

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-2025-986712
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7885bd09");
  # https://lore.kernel.org/linux-cve-announce/2024052125-CVE-2021-47300-eee0@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?65f9ac54");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2021-47300");
  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: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-2021-47300");

  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:"2025/09/23");
  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:"^20.1070e([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1070e', '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': '1070e',
    'pkgs': [
      {'reference':'kernel-5.10.0-74.16', 'sp':'1070e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-74.16', 'sp':'1070e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-74.16', 'sp':'1070e', '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');
}