Unity Linux 20.1050a Security Update: kernel (UTSA-2026-098830)

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

include('compat.inc');

if (description)
{
  script_id(340367);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/28");

  script_cve_id("CVE-2025-38346");

  script_name(english:"Unity Linux 20.1050a Security Update: kernel (UTSA-2026-098830)");

  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-2026-098830 advisory.

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

    ftrace: Fix UAF when lookup kallsym after ftrace disabled

    The following issue happens with a buggy module:

    BUG: unable to handle page fault for address: ffffffffc05d0218
    PGD 1bd66f067 P4D 1bd66f067 PUD 1bd671067 PMD 101808067 PTE 0
    Oops: Oops: 0000 [#1] SMP KASAN PTI
    Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
    RIP: 0010:sized_strscpy+0x81/0x2f0
    RSP: 0018:ffff88812d76fa08 EFLAGS: 00010246
    RAX: 0000000000000000 RBX: ffffffffc0601010 RCX: dffffc0000000000
    RDX: 0000000000000038 RSI: dffffc0000000000 RDI: ffff88812608da2d
    RBP: 8080808080808080 R08: ffff88812608da2d R09: ffff88812608da68
    R10: ffff88812608d82d R11: ffff88812608d810 R12: 0000000000000038
    R13: ffff88812608da2d R14: ffffffffc05d0218 R15: fefefefefefefeff
    FS:  00007fef552de740(0000) GS:ffff8884251c7000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: ffffffffc05d0218 CR3: 00000001146f0000 CR4: 00000000000006f0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
     <TASK>
     ftrace_mod_get_kallsym+0x1ac/0x590
     update_iter_mod+0x239/0x5b0
     s_next+0x5b/0xa0
     seq_read_iter+0x8c9/0x1070
     seq_read+0x249/0x3b0
     proc_reg_read+0x1b0/0x280
     vfs_read+0x17f/0x920
     ksys_read+0xf3/0x1c0
     do_syscall_64+0x5f/0x2e0
     entry_SYSCALL_64_after_hwframe+0x76/0x7e

    The above issue may happen as follows:
    (1) Add kprobe tracepoint;
    (2) insmod test.ko;
    (3)  Module triggers ftrace disabled;
    (4) rmmod test.ko;
    (5) cat /proc/kallsyms; --> Will trigger UAF as test.ko already removed;
    ftrace_mod_get_kallsym()
    ...
    strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
    ...

    The problem is when a module triggers an issue with ftrace and
    sets ftrace_disable. The ftrace_disable is set when an anomaly is
    discovered and to prevent any more damage, ftrace stops all text
    modification. The issue that happened was that the ftrace_disable stops
    more than just the text modification.

    When a module is loaded, its init functions can also be traced. Because
    kallsyms deletes the init functions after a module has loaded, ftrace
    saves them when the module is loaded and function tracing is enabled. This
    allows the output of the function trace to show the init function names
    instead of just their raw memory addresses.

    When a module is removed, ftrace_release_mod() is called, and if
    ftrace_disable is set, it just returns without doing anything more. The
    problem here is that it leaves the mod_list still around and if kallsyms
    is called, it will call into this code and access the module memory that
    has already been freed as it will return:

      strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);

    Where the mod no longer exists and triggers a UAF bug.

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-2026-098830
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?c1891a89");
  # https://lore.kernel.org/linux-cve-announce/2025071035-CVE-2025-38346-8cb6@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?f7348902");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2025-38346");
  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-2025-38346");

  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:"2025/07/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/26");

  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:"^(20.1050a)([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1050a', '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': '1050a',
    'pkgs': [
      {'reference':'kernel-4.19.0-91.82.132.24.uelc20', 'sp':'1050a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.132.24.uelc20', 'sp':'1050a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.132.24.uelc20', 'sp':'1050a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.132.24.uelc20', 'sp':'1050a', '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');
}