Unity Linux 20.1050e Security Update: kernel (UTSA-2026-100102)

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

include('compat.inc');

if (description)
{
  script_id(336907);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/17");

  script_cve_id("CVE-2025-40349");

  script_name(english:"Unity Linux 20.1050e Security Update: kernel (UTSA-2026-100102)");

  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-2026-100102 advisory.

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

    hfs: validate record offset in hfsplus_bmap_alloc

    hfsplus_bmap_alloc can trigger a crash if a
    record offset or length is larger than node_size

    [   15.264282] BUG: KASAN: slab-out-of-bounds in hfsplus_bmap_alloc+0x887/0x8b0
    [   15.265192] Read of size 8 at addr ffff8881085ca188 by task test/183
    [   15.265949]
    [   15.266163] CPU: 0 UID: 0 PID: 183 Comm: test Not tainted 6.17.0-rc2-gc17b750b3ad9 #14
    PREEMPT(voluntary)
    [   15.266165] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2
    04/01/2014
    [   15.266167] Call Trace:
    [   15.266168]  <TASK>
    [   15.266169]  dump_stack_lvl+0x53/0x70
    [   15.266173]  print_report+0xd0/0x660
    [   15.266181]  kasan_report+0xce/0x100
    [   15.266185]  hfsplus_bmap_alloc+0x887/0x8b0
    [   15.266208]  hfs_btree_inc_height.isra.0+0xd5/0x7c0
    [   15.266217]  hfsplus_brec_insert+0x870/0xb00
    [   15.266222]  __hfsplus_ext_write_extent+0x428/0x570
    [   15.266225]  __hfsplus_ext_cache_extent+0x5e/0x910
    [   15.266227]  hfsplus_ext_read_extent+0x1b2/0x200
    [   15.266233]  hfsplus_file_extend+0x5a7/0x1000
    [   15.266237]  hfsplus_get_block+0x12b/0x8c0
    [   15.266238]  __block_write_begin_int+0x36b/0x12c0
    [   15.266251]  block_write_begin+0x77/0x110
    [   15.266252]  cont_write_begin+0x428/0x720
    [   15.266259]  hfsplus_write_begin+0x51/0x100
    [   15.266262]  cont_write_begin+0x272/0x720
    [   15.266270]  hfsplus_write_begin+0x51/0x100
    [   15.266274]  generic_perform_write+0x321/0x750
    [   15.266285]  generic_file_write_iter+0xc3/0x310
    [   15.266289]  __kernel_write_iter+0x2fd/0x800
    [   15.266296]  dump_user_range+0x2ea/0x910
    [   15.266301]  elf_core_dump+0x2a94/0x2ed0
    [   15.266320]  vfs_coredump+0x1d85/0x45e0
    [   15.266349]  get_signal+0x12e3/0x1990
    [   15.266357]  arch_do_signal_or_restart+0x89/0x580
    [   15.266362]  irqentry_exit_to_user_mode+0xab/0x110
    [   15.266364]  asm_exc_page_fault+0x26/0x30
    [   15.266366] RIP: 0033:0x41bd35
    [   15.266367] Code: bc d1 f3 0f 7f 27 f3 0f 7f 6f 10 f3 0f 7f 77 20 f3 0f 7f 7f 30 49 83 c0 0f 49 29 d0
    48 8d 7c 17 31 e9 9f 0b 00 00 66 0f ef c0 <f3> 0f 6f 0e f3 0f 6f 56 10 66 0f 74 c1 66 0f d7 d0 49 83 f8f
    [   15.266369] RSP: 002b:00007ffc9e62d078 EFLAGS: 00010283
    [   15.266371] RAX: 00007ffc9e62d100 RBX: 0000000000000000 RCX: 0000000000000000
    [   15.266372] RDX: 00000000000000e0 RSI: 0000000000000000 RDI: 00007ffc9e62d100
    [   15.266373] RBP: 0000400000000040 R08: 00000000000000e0 R09: 0000000000000000
    [   15.266374] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
    [   15.266375] R13: 0000000000000000 R14: 0000000000000000 R15: 0000400000000000
    [   15.266376]  </TASK>

    When calling hfsplus_bmap_alloc to allocate a free node, this function
    first retrieves the bitmap from header node and map node using node->page
    together with the offset and length from hfs_brec_lenoff

    ```
    len = hfs_brec_lenoff(node, 2, &off16);
    off = off16;

    off += node->page_offset;
    pagep = node->page + (off >> PAGE_SHIFT);
    data = kmap_local_page(*pagep);
    ```

    However, if the retrieved offset or length is invalid(i.e. exceeds
    node_size), the code may end up accessing pages outside the allocated
    range for this node.

    This patch adds proper validation of both offset and length before use,
    preventing out-of-bounds page access. Move is_bnode_offset_valid and
    check_and_correct_requested_length to hfsplus_fs.h, as they may be
    required by other functions.

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-2026-100102
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?601feaaf");
  # https://lore.kernel.org/linux-cve-announce/2025121635-CVE-2025-40349-82c6@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?a3e73773");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2025-40349");
  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:L/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-2025-40349");

  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:"2025/11/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/17");

  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) 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/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:"^20.1050e([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1050e', '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': '1050e',
    'pkgs': [
      {'reference':'kernel-5.10.0-27.18.uel20', 'sp':'1050e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-27.18.uel20', 'sp':'1050e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-27.18.uel20', 'sp':'1050e', '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');
}