Unity Linux 20.1050e Security Update: kernel (UTSA-2026-100184)

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

include('compat.inc');

if (description)
{
  script_id(336030);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/17");

  script_cve_id("CVE-2025-38194");

  script_name(english:"Unity Linux 20.1050e Security Update: kernel (UTSA-2026-100184)");

  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-2026-100184 advisory.

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

    jffs2: check that raw node were preallocated before writing summary

    Syzkaller detected a kernel bug in jffs2_link_node_ref, caused by fault
    injection in jffs2_prealloc_raw_node_refs. jffs2_sum_write_sumnode doesn't
    check return value of jffs2_prealloc_raw_node_refs and simply lets any
    error propagate into jffs2_sum_write_data, which eventually calls
    jffs2_link_node_ref in order to link the summary to an expectedly allocated
    node.

    kernel BUG at fs/jffs2/nodelist.c:592!
    invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
    CPU: 1 PID: 31277 Comm: syz-executor.7 Not tainted 6.1.128-syzkaller-00139-ge10f83ca10a1 #0
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
    RIP: 0010:jffs2_link_node_ref+0x570/0x690 fs/jffs2/nodelist.c:592
    Call Trace:
     <TASK>
     jffs2_sum_write_data fs/jffs2/summary.c:841 [inline]
     jffs2_sum_write_sumnode+0xd1a/0x1da0 fs/jffs2/summary.c:874
     jffs2_do_reserve_space+0xa18/0xd60 fs/jffs2/nodemgmt.c:388
     jffs2_reserve_space+0x55f/0xaa0 fs/jffs2/nodemgmt.c:197
     jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362
     jffs2_write_end+0x726/0x15d0 fs/jffs2/file.c:301
     generic_perform_write+0x314/0x5d0 mm/filemap.c:3856
     __generic_file_write_iter+0x2ae/0x4d0 mm/filemap.c:3973
     generic_file_write_iter+0xe3/0x350 mm/filemap.c:4005
     call_write_iter include/linux/fs.h:2265 [inline]
     do_iter_readv_writev+0x20f/0x3c0 fs/read_write.c:735
     do_iter_write+0x186/0x710 fs/read_write.c:861
     vfs_iter_write+0x70/0xa0 fs/read_write.c:902
     iter_file_splice_write+0x73b/0xc90 fs/splice.c:685
     do_splice_from fs/splice.c:763 [inline]
     direct_splice_actor+0x10c/0x170 fs/splice.c:950
     splice_direct_to_actor+0x337/0xa10 fs/splice.c:896
     do_splice_direct+0x1a9/0x280 fs/splice.c:1002
     do_sendfile+0xb13/0x12c0 fs/read_write.c:1255
     __do_sys_sendfile64 fs/read_write.c:1323 [inline]
     __se_sys_sendfile64 fs/read_write.c:1309 [inline]
     __x64_sys_sendfile64+0x1cf/0x210 fs/read_write.c:1309
     do_syscall_x64 arch/x86/entry/common.c:51 [inline]
     do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81
     entry_SYSCALL_64_after_hwframe+0x6e/0xd8

    Fix this issue by checking return value of jffs2_prealloc_raw_node_refs
    before calling jffs2_sum_write_data.

    Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

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-2026-100184
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0ae8c8f4");
  # https://lore.kernel.org/linux-cve-announce/2025070415-CVE-2025-38194-1c50@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?100b186a");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2025-38194");
  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-2025-38194");

  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:"2025/07/04");
  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');
}