Unity Linux 20.1070a Security Update: kernel (UTSA-2025-989229)

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

include('compat.inc');

if (description)
{
  script_id(273079);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/05");

  script_cve_id("CVE-2021-47375");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2025-989229)");

  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-2025-989229 advisory.

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

    blktrace: Fix uaf in blk_trace access after removing by sysfs

    There is an use-after-free problem triggered by following process:

          P1(sda)                           P2(sdb)
                            echo 0 > /sys/block/sdb/trace/enable
                              blk_trace_remove_queue
                                synchronize_rcu
                                blk_trace_free
                                  relay_close
    rcu_read_lock
    __blk_add_trace
      trace_note_tsk
      (Iterate running_trace_list)
                                    relay_close_buf
                                      relay_destroy_buf
                                        kfree(buf)
        trace_note(sdb's bt)
          relay_reserve
            buf->offset <- nullptr deference (use-after-free) !!!
    rcu_read_unlock

    [  502.714379] BUG: kernel NULL pointer dereference, address:
    0000000000000010
    [  502.715260] #PF: supervisor read access in kernel mode
    [  502.715903] #PF: error_code(0x0000) - not-present page
    [  502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0
    [  502.717252] Oops: 0000 [#1] SMP
    [  502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360
    [  502.732872] Call Trace:
    [  502.733193]  __blk_add_trace.cold+0x137/0x1a3
    [  502.733734]  blk_add_trace_rq+0x7b/0xd0
    [  502.734207]  blk_add_trace_rq_issue+0x54/0xa0
    [  502.734755]  blk_mq_start_request+0xde/0x1b0
    [  502.735287]  scsi_queue_rq+0x528/0x1140
    ...
    [  502.742704]  sg_new_write.isra.0+0x16e/0x3e0
    [  502.747501]  sg_ioctl+0x466/0x1100

    Reproduce method:
      ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
      ioctl(/dev/sda, BLKTRACESTART)
      ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
      ioctl(/dev/sdb, BLKTRACESTART)

      echo 0 > /sys/block/sdb/trace/enable &
      // Add delay(mdelay/msleep) before kernel enters blk_trace_free()

      ioctl$SG_IO(/dev/sda, SG_IO, ...)
      // Enters trace_note_tsk() after blk_trace_free() returned
      // Use mdelay in rcu region rather than msleep(which may schedule out)

    Remove blk_trace from running_list before calling blk_trace_free() by
    sysfs if blk_trace is at Blktrace_running state.

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-2025-989229
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?4df058e8");
  # https://lore.kernel.org/linux-cve-announce/2024052141-CVE-2021-47375-8849@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?e8d1462f");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2021-47375");
  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:N/UI:N/S:U/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-47375");

  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:"2025/11/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/11/05");

  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-5.10.0-79.4.2', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.4.2', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.4.2', 'sp':'1070a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.4.2', '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');
}