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Unity Linux 20.1060a / 20.1070a Security Update: kernel (UTSA-2025-993232)

🗓️ 31 Dec 2025 00:00:00Reported by TenableType 
nessus
 nessus
🔗 www.tenable.com👁 1 Views

Security update fixes NFS delegation teardown deadlock by decrementing sc_count on failed dl_recall.

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

include('compat.inc');

if (description)
{
  script_id(281277);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/12/31");

  script_cve_id("CVE-2025-37871");

  script_name(english:"Unity Linux 20.1060a / 20.1070a Security Update: kernel (UTSA-2025-993232)");

  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-2025-993232 advisory.

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

    nfsd: decrease sc_count directly if fail to queue dl_recall

    A deadlock warning occurred when invoking nfs4_put_stid following a failed
    dl_recall queue operation:
                T1                            T2
                                    nfs4_laundromat
                                     nfs4_get_client_reaplist
                                      nfs4_anylock_blockers
    __break_lease
     spin_lock // ctx->flc_lock
                                       spin_lock // clp->cl_lock
                                       nfs4_lockowner_has_blockers
                                        locks_owner_has_blockers
                                         spin_lock // flctx->flc_lock
     nfsd_break_deleg_cb
      nfsd_break_one_deleg
       nfs4_put_stid
        refcount_dec_and_lock
         spin_lock // clp->cl_lock

    When a file is opened, an nfs4_delegation is allocated with sc_count
    initialized to 1, and the file_lease holds a reference to the delegation.
    The file_lease is then associated with the file through kernel_setlease.

    The disassociation is performed in nfsd4_delegreturn via the following
    call chain:
    nfsd4_delegreturn --> destroy_delegation --> destroy_unhashed_deleg -->
    nfs4_unlock_deleg_lease --> kernel_setlease --> generic_delete_lease
    The corresponding sc_count reference will be released after this
    disassociation.

    Since nfsd_break_one_deleg executes while holding the flc_lock, the
    disassociation process becomes blocked when attempting to acquire flc_lock
    in generic_delete_lease. This means:
    1) sc_count in nfsd_break_one_deleg will not be decremented to 0;
    2) The nfs4_put_stid called by nfsd_break_one_deleg will not attempt to
    acquire cl_lock;
    3) Consequently, no deadlock condition is created.

    Given that sc_count in nfsd_break_one_deleg remains non-zero, we can
    safely perform refcount_dec on sc_count directly. This approach
    effectively avoids triggering deadlock warnings.

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-2025-993232
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?19ea0b0f");
  # https://lore.kernel.org/linux-cve-announce/2025050959-CVE-2025-37871-937a@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b1feaccc");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2025-37871");
  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-2025-37871");

  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:"2025/05/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/12/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/12/31");

  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:"^20.1060a|20.1070a([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1060a / 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': '1060a',
    'pkgs': [
      {'reference':'kernel-5.10.0-46.38', 'sp':'1060a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-46.38', 'sp':'1060a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-46.38', 'sp':'1060a', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  },
  {
    'release': '20',
    'sp': '1070a',
    'pkgs': [
      {'reference':'kernel-5.10.0-79.5', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.5', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.5', 'sp':'1070a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.5', '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');
}

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31 Dec 2025 00:00Current
6.2Medium risk
Vulners AI Score6.2
CVSS 3.15.5
EPSS0.00066
1