Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986947)

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

include('compat.inc');

if (description)
{
  script_id(268247);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/10/15");

  script_cve_id("CVE-2021-47191");

  script_name(english:"Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986947)");

  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-2025-986947 advisory.

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

    scsi: scsi_debug: Fix out-of-bound read in resp_readcap16()

    The following warning was observed running syzkaller:

    [ 3813.830724] sg_write: data in/out 65466/242 bytes for SCSI command 0x9e-- guessing data in;
    [ 3813.830724]    program syz-executor not setting count and/or reply_len properly
    [ 3813.836956] ==================================================================
    [ 3813.839465] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x157/0x1e0
    [ 3813.841773] Read of size 4096 at addr ffff8883cf80f540 by task syz-executor/1549
    [ 3813.846612] Call Trace:
    [ 3813.846995]  dump_stack+0x108/0x15f
    [ 3813.847524]  print_address_description+0xa5/0x372
    [ 3813.848243]  kasan_report.cold+0x236/0x2a8
    [ 3813.849439]  check_memory_region+0x240/0x270
    [ 3813.850094]  memcpy+0x30/0x80
    [ 3813.850553]  sg_copy_buffer+0x157/0x1e0
    [ 3813.853032]  sg_copy_from_buffer+0x13/0x20
    [ 3813.853660]  fill_from_dev_buffer+0x135/0x370
    [ 3813.854329]  resp_readcap16+0x1ac/0x280
    [ 3813.856917]  schedule_resp+0x41f/0x1630
    [ 3813.858203]  scsi_debug_queuecommand+0xb32/0x17e0
    [ 3813.862699]  scsi_dispatch_cmd+0x330/0x950
    [ 3813.863329]  scsi_request_fn+0xd8e/0x1710
    [ 3813.863946]  __blk_run_queue+0x10b/0x230
    [ 3813.864544]  blk_execute_rq_nowait+0x1d8/0x400
    [ 3813.865220]  sg_common_write.isra.0+0xe61/0x2420
    [ 3813.871637]  sg_write+0x6c8/0xef0
    [ 3813.878853]  __vfs_write+0xe4/0x800
    [ 3813.883487]  vfs_write+0x17b/0x530
    [ 3813.884008]  ksys_write+0x103/0x270
    [ 3813.886268]  __x64_sys_write+0x77/0xc0
    [ 3813.886841]  do_syscall_64+0x106/0x360
    [ 3813.887415]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

    This issue can be reproduced with the following syzkaller log:

    r0 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x26e1, 0x0)
    r1 = syz_open_procfs(0xffffffffffffffff, &(0x7f0000000000)='fd/3\x00')
    open_by_handle_at(r1, &(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000)
    r2 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x40782)
    write$binfmt_aout(r2, &(0x7f0000000340)=ANY=[@ANYBLOB=00000000deff000000000000000000000000000000000000000
    000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb360
    7fcf611a22dd04310d28c75039d], 0x126)

    In resp_readcap16() we get int alloc_len value -1104926854, and then pass
    the huge arr_len to fill_from_dev_buffer(), but arr is only 32 bytes. This
    leads to OOB in sg_copy_buffer().

    To solve this issue, define alloc_len as u32.

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-2025-986947
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?dde0f691");
  # https://lore.kernel.org/linux-cve-announce/2024041034-CVE-2021-47191-ec4f@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d0afcbcb");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2021-47191");
  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: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:H/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-2021-47191");

  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:"2021/07/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/09/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/10/07");

  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:"^20.1070e([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1070e', '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': '1070e',
    'pkgs': [
      {'reference':'kernel-5.10.0-74.16', 'sp':'1070e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-74.16', 'sp':'1070e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-74.16', 'sp':'1070e', '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');
}