Unity Linux 20.1050e Security Update: kernel (UTSA-2026-006775)

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

include('compat.inc');

if (description)
{
  script_id(305485);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/08");

  script_cve_id("CVE-2024-35886");

  script_name(english:"Unity Linux 20.1050e Security Update: kernel (UTSA-2026-006775)");

  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-2026-006775 advisory.

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

    ipv6: Fix infinite recursion in fib6_dump_done().

    syzkaller reported infinite recursive calls of fib6_dump_done() during
    netlink socket destruction.  [1]

    From the log, syzkaller sent an AF_UNSPEC RTM_GETROUTE message, and then
    the response was generated.  The following recvmmsg() resumed the dump
    for IPv6, but the first call of inet6_dump_fib() failed at kzalloc() due
    to the fault injection.  [0]

      12:01:34 executing program 3:
      r0 = socket$nl_route(0x10, 0x3, 0x0)
      sendmsg$nl_route(r0, ... snip ...)
      recvmmsg(r0, ... snip ...) (fail_nth: 8)

    Here, fib6_dump_done() was set to nlk_sk(sk)->cb.done, and the next call
    of inet6_dump_fib() set it to nlk_sk(sk)->cb.args[3].  syzkaller stopped
    receiving the response halfway through, and finally netlink_sock_destruct()
    called nlk_sk(sk)->cb.done().

    fib6_dump_done() calls fib6_dump_end() and nlk_sk(sk)->cb.done() if it
    is still not NULL.  fib6_dump_end() rewrites nlk_sk(sk)->cb.done() by
    nlk_sk(sk)->cb.args[3], but it has the same function, not NULL, calling
    itself recursively and hitting the stack guard page.

    To avoid the issue, let's set the destructor after kzalloc().

    [0]:
    FAULT_INJECTION: forcing a failure.
    name failslab, interval 1, probability 0, space 0, times 0
    CPU: 1 PID: 432110 Comm: syz-executor.3 Not tainted 6.8.0-12821-g537c2e91d354-dirty #11
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org
    04/01/2014
    Call Trace:
     <TASK>
     dump_stack_lvl (lib/dump_stack.c:117)
     should_fail_ex (lib/fault-inject.c:52 lib/fault-inject.c:153)
     should_failslab (mm/slub.c:3733)
     kmalloc_trace (mm/slub.c:3748 mm/slub.c:3827 mm/slub.c:3992)
     inet6_dump_fib (./include/linux/slab.h:628 ./include/linux/slab.h:749 net/ipv6/ip6_fib.c:662)
     rtnl_dump_all (net/core/rtnetlink.c:4029)
     netlink_dump (net/netlink/af_netlink.c:2269)
     netlink_recvmsg (net/netlink/af_netlink.c:1988)
     ____sys_recvmsg (net/socket.c:1046 net/socket.c:2801)
     ___sys_recvmsg (net/socket.c:2846)
     do_recvmmsg (net/socket.c:2943)
     __x64_sys_recvmmsg (net/socket.c:3041 net/socket.c:3034 net/socket.c:3034)

    [1]:
    BUG: TASK stack guard page was hit at 00000000f2fa9af1 (stack is 00000000b7912430..000000009a436beb)
    stack guard page: 0000 [#1] PREEMPT SMP KASAN
    CPU: 1 PID: 223719 Comm: kworker/1:3 Not tainted 6.8.0-12821-g537c2e91d354-dirty #11
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org
    04/01/2014
    Workqueue: events netlink_sock_destruct_work
    RIP: 0010:fib6_dump_done (net/ipv6/ip6_fib.c:570)
    Code: 3c 24 e8 f3 e9 51 fd e9 28 fd ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 41 57 41
    56 41 55 41 54 55 48 89 fd <53> 48 8d 5d 60 e8 b6 4d 07 fd 48 89 da 48 b8 00 00 00 00 00 fc ff
    RSP: 0018:ffffc9000d980000 EFLAGS: 00010293
    RAX: 0000000000000000 RBX: ffffffff84405990 RCX: ffffffff844059d3
    RDX: ffff8881028e0000 RSI: ffffffff84405ac2 RDI: ffff88810c02f358
    RBP: ffff88810c02f358 R08: 0000000000000007 R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000224 R12: 0000000000000000
    R13: ffff888007c82c78 R14: ffff888007c82c68 R15: ffff888007c82c68
    FS:  0000000000000000(0000) GS:ffff88811b100000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: ffffc9000d97fff8 CR3: 0000000102309002 CR4: 0000000000770ef0
    PKRU: 55555554
    Call Trace:
     <#DF>
     </#DF>
     <TASK>
     fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1))
     fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1))
     ...
     fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1))
     fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1))
     netlink_sock_destruct (net/netlink/af_netlink.c:401)
     __sk_destruct (net/core/sock.c:2177 (discriminator 2))
     sk_destruct (net/core/sock.c:2224)
     __sk_free (net/core/sock.c:2235)
     sk_free (net/core/sock.c:2246)
     process_one_work (kernel/workqueue.c:3259)
     worker_thread (kernel/workqueue.c:3329 kernel/workqueue.
    ---truncated---

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-2026-006775
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9ae09211");
  # https://lore.kernel.org/linux-cve-announce/2024051946-CVE-2024-35886-19d4@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?77076342");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2024-35886");
  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-2024-35886");

  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:"2024/04/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/04/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/04/08");

  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-5.10.0-27.5', 'sp':'1050e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-27.5', 'sp':'1050e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-27.5', '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');
}