Unity Linux 20.1050e Security Update: kernel (UTSA-2026-099755)

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

include('compat.inc');

if (description)
{
  script_id(337044);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/17");

  script_cve_id("CVE-2026-45970");

  script_name(english:"Unity Linux 20.1050e Security Update: kernel (UTSA-2026-099755)");

  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-2026-099755 advisory.

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

    bonding: alb: fix UAF in rlb_arp_recv during bond up/down

    The ALB RX path may access rx_hashtbl concurrently with bond
    teardown. During rapid bond up/down cycles, rlb_deinitialize()
    frees rx_hashtbl while RX handlers are still running, leading
    to a null pointer dereference detected by KASAN.

    However, the root cause is that rlb_arp_recv() can still be accessed
    after setting recv_probe to NULL, which is actually a use-after-free
    (UAF) issue. That is the reason for using the referenced commit in the
    Fixes tag.

    [  214.174138] Oops: general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000
    [#1] SMP KASAN PTI
    [  214.186478] KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef]
    [  214.194933] CPU: 30 UID: 0 PID: 2375 Comm: ping Kdump: loaded Not tainted 6.19.0-rc8+ #2
    PREEMPT(voluntary)
    [  214.205907] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.14.0 01/14/2022
    [  214.214357] RIP: 0010:rlb_arp_recv+0x505/0xab0 [bonding]
    [  214.220320] Code: 0f 85 2b 05 00 00 48 b8 00 00 00 00 00 fc ff df 40 0f b6 ed 48 c1 e5 06 49 03 ad 78
    01 00 00 48 8d 7d 28 48 89 fa 48 c1 ea 03 <0f> b6
     04 02 84 c0 74 06 0f 8e 12 05 00 00 80 7d 28 00 0f 84 8c 00
    [  214.241280] RSP: 0018:ffffc900073d8870 EFLAGS: 00010206
    [  214.247116] RAX: dffffc0000000000 RBX: ffff888168556822 RCX: ffff88816855681e
    [  214.255082] RDX: 000000000000001d RSI: dffffc0000000000 RDI: 00000000000000e8
    [  214.263048] RBP: 00000000000000c0 R08: 0000000000000002 R09: ffffed11192021c8
    [  214.271013] R10: ffff8888c9010e43 R11: 0000000000000001 R12: 1ffff92000e7b119
    [  214.278978] R13: ffff8888c9010e00 R14: ffff888168556822 R15: ffff888168556810
    [  214.286943] FS:  00007f85d2d9cb80(0000) GS:ffff88886ccb3000(0000) knlGS:0000000000000000
    [  214.295966] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    [  214.302380] CR2: 00007f0d047b5e34 CR3: 00000008a1c2e002 CR4: 00000000001726f0
    [  214.310347] Call Trace:
    [  214.313070]  <IRQ>
    [  214.315318]  ? __pfx_rlb_arp_recv+0x10/0x10 [bonding]
    [  214.320975]  bond_handle_frame+0x166/0xb60 [bonding]
    [  214.326537]  ? __pfx_bond_handle_frame+0x10/0x10 [bonding]
    [  214.332680]  __netif_receive_skb_core.constprop.0+0x576/0x2710
    [  214.339199]  ? __pfx_arp_process+0x10/0x10
    [  214.343775]  ? sched_balance_find_src_group+0x98/0x630
    [  214.349513]  ? __pfx___netif_receive_skb_core.constprop.0+0x10/0x10
    [  214.356513]  ? arp_rcv+0x307/0x690
    [  214.360311]  ? __pfx_arp_rcv+0x10/0x10
    [  214.364499]  ? __lock_acquire+0x58c/0xbd0
    [  214.368975]  __netif_receive_skb_one_core+0xae/0x1b0
    [  214.374518]  ? __pfx___netif_receive_skb_one_core+0x10/0x10
    [  214.380743]  ? lock_acquire+0x10b/0x140
    [  214.385026]  process_backlog+0x3f1/0x13a0
    [  214.389502]  ? process_backlog+0x3aa/0x13a0
    [  214.394174]  __napi_poll.constprop.0+0x9f/0x370
    [  214.399233]  net_rx_action+0x8c1/0xe60
    [  214.403423]  ? __pfx_net_rx_action+0x10/0x10
    [  214.408193]  ? lock_acquire.part.0+0xbd/0x260
    [  214.413058]  ? sched_clock_cpu+0x6c/0x540
    [  214.417540]  ? mark_held_locks+0x40/0x70
    [  214.421920]  handle_softirqs+0x1fd/0x860
    [  214.426302]  ? __pfx_handle_softirqs+0x10/0x10
    [  214.431264]  ? __neigh_event_send+0x2d6/0xf50
    [  214.436131]  do_softirq+0xb1/0xf0
    [  214.439830]  </IRQ>

    The issue is reproducible by repeatedly running
    ip link set bond0 up/down while receiving ARP messages, where
    rlb_arp_recv() can race with rlb_deinitialize() and dereference
    a freed rx_hashtbl entry.

    Fix this by setting recv_probe to NULL and then calling
    synchronize_net() to wait for any concurrent RX processing to finish.
    This ensures that no RX handler can access rx_hashtbl after it is freed
    in bond_alb_deinitialize().

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-2026-099755
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?31fa41f3");
  # https://lore.kernel.org/linux-cve-announce/2026052736-CVE-2026-45970-72d9@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?4d718cc8");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2026-45970");
  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-2026-45970");

  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:"2026/03/12");
  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');
}