Unity Linux 20.1050e Security Update: kernel (UTSA-2026-102003)

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

include('compat.inc');

if (description)
{
  script_id(337330);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/18");

  script_cve_id("CVE-2026-43167");

  script_name(english:"Unity Linux 20.1050e Security Update: kernel (UTSA-2026-102003)");

  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-2026-102003 advisory.

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

    xfrm: always flush state and policy upon NETDEV_UNREGISTER event

    syzbot is reporting that struct xfrm_state refcount is leaking.

      unregister_netdevice: waiting for netdevsim0 to become free. Usage count = 2
      ref_tracker: netdev@ffff888052f24618 has 1/1 users at
           __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline]
           netdev_tracker_alloc include/linux/netdevice.h:4412 [inline]
           xfrm_dev_state_add+0x3a5/0x1080 net/xfrm/xfrm_device.c:316
           xfrm_state_construct net/xfrm/xfrm_user.c:986 [inline]
           xfrm_add_sa+0x34ff/0x5fa0 net/xfrm/xfrm_user.c:1022
           xfrm_user_rcv_msg+0x58e/0xc00 net/xfrm/xfrm_user.c:3507
           netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550
           xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3529
           netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
           netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
           netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894
           sock_sendmsg_nosec net/socket.c:727 [inline]
           __sock_sendmsg net/socket.c:742 [inline]
           ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592
           ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646
           __sys_sendmsg+0x16d/0x220 net/socket.c:2678
           do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
           do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
           entry_SYSCALL_64_after_hwframe+0x77/0x7f

    This is because commit d77e38e612a0 (xfrm: Add an IPsec hardware
    offloading API) implemented xfrm_dev_unregister() as no-op despite
    xfrm_dev_state_add() from xfrm_state_construct() acquires a reference
    to struct net_device.
    I guess that that commit expected that NETDEV_DOWN event is fired before
    NETDEV_UNREGISTER event fires, and also assumed that xfrm_dev_state_add()
    is called only if (dev->features & NETIF_F_HW_ESP) != 0.

    Sabrina Dubroca identified steps to reproduce the same symptoms as below.

      echo 0 > /sys/bus/netdevsim/new_device
      dev=$(ls -1 /sys/bus/netdevsim/devices/netdevsim0/net/)
      ip xfrm state add src 192.168.13.1 dst 192.168.13.2 proto esp
         spi 0x1000 mode tunnel aead 'rfc4106(gcm(aes))' $key 128
         offload crypto dev $dev dir out
      ethtool -K $dev esp-hw-offload off
      echo 0 > /sys/bus/netdevsim/del_device

    Like these steps indicate, the NETIF_F_HW_ESP bit can be cleared after
    xfrm_dev_state_add() acquired a reference to struct net_device.
    Also, xfrm_dev_state_add() does not check for the NETIF_F_HW_ESP bit
    when acquiring a reference to struct net_device.

    Commit 03891f820c21 (xfrm: handle NETDEV_UNREGISTER for xfrm device)
    re-introduced the NETDEV_UNREGISTER event to xfrm_dev_event(), but that
    commit for unknown reason chose to share xfrm_dev_down() between the
    NETDEV_DOWN event and the NETDEV_UNREGISTER event.
    I guess that that commit missed the behavior in the previous paragraph.

    Therefore, we need to re-introduce xfrm_dev_unregister() in order to
    release the reference to struct net_device by unconditionally flushing
    state and policy.

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-2026-102003
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?1beed84f");
  # https://lore.kernel.org/linux-cve-announce/2026050634-CVE-2026-43167-6243@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?37d7fa94");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2026-43167");
  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-2026-43167");

  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:"2026/04/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/18");

  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-4.19.90-2211.5.0.0178.67.uel20', 'sp':'1050e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2211.5.0.0178.67.uel20', 'sp':'1050e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2211.5.0.0178.67.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');
}