Unity Linux 20.1070e Security Update: kernel (UTSA-2026-005577)

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

include('compat.inc');

if (description)
{
  script_id(300315);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/03/03");

  script_cve_id("CVE-2024-49949");

  script_name(english:"Unity Linux 20.1070e Security Update: kernel (UTSA-2026-005577)");

  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-2026-005577 advisory.

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

    net: avoid potential underflow in qdisc_pkt_len_init() with UFO

    After commit 7c6d2ecbda83 (net: be more gentle about silly gso
    requests coming from user) virtio_net_hdr_to_skb() had sanity check
    to detect malicious attempts from user space to cook a bad GSO packet.

    Then commit cf9acc90c80ec (net: virtio_net_hdr_to_skb: count
    transport header in UFO) while fixing one issue, allowed user space
    to cook a GSO packet with the following characteristic :

    IPv4 SKB_GSO_UDP, gso_size=3, skb->len = 28.

    When this packet arrives in qdisc_pkt_len_init(), we end up
    with hdr_len = 28 (IPv4 header + UDP header), matching skb->len

    Then the following sets gso_segs to 0 :

    gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
                            shinfo->gso_size);

    Then later we set qdisc_skb_cb(skb)->pkt_len to back to zero :/

    qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;

    This leads to the following crash in fq_codel [1]

    qdisc_pkt_len_init() is best effort, we only want an estimation
    of the bytes sent on the wire, not crashing the kernel.

    This patch is fixing this particular issue, a following one
    adds more sanity checks for another potential bug.

    [1]
    [   70.724101] BUG: kernel NULL pointer dereference, address: 0000000000000000
    [   70.724561] #PF: supervisor read access in kernel mode
    [   70.724561] #PF: error_code(0x0000) - not-present page
    [   70.724561] PGD 10ac61067 P4D 10ac61067 PUD 107ee2067 PMD 0
    [   70.724561] Oops: Oops: 0000 [#1] SMP NOPTI
    [   70.724561] CPU: 11 UID: 0 PID: 2163 Comm: b358537762 Not tainted 6.11.0-virtme #991
    [   70.724561] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2
    04/01/2014
    [   70.724561] RIP: 0010:fq_codel_enqueue (net/sched/sch_fq_codel.c:120 net/sched/sch_fq_codel.c:168
    net/sched/sch_fq_codel.c:230) sch_fq_codel
    [ 70.724561] Code: 24 08 49 c1 e1 06 44 89 7c 24 18 45 31 ed 45 31 c0 31 ff 89 44 24 14 4c 03 8b 90 01 00
    00 eb 04 39 ca 73 37 4d 8b 39 83 c7 01 <49> 8b 17 49 89 11 41 8b 57 28 45 8b 5f 34 49 c7 07 00 00 00 00 49
    All code
    ========
       0:   24 08                   and    $0x8,%al
       2:   49 c1 e1 06             shl    $0x6,%r9
       6:   44 89 7c 24 18          mov    %r15d,0x18(%rsp)
       b:   45 31 ed                xor    %r13d,%r13d
       e:   45 31 c0                xor    %r8d,%r8d
      11:   31 ff                   xor    %edi,%edi
      13:   89 44 24 14             mov    %eax,0x14(%rsp)
      17:   4c 03 8b 90 01 00 00    add    0x190(%rbx),%r9
      1e:   eb 04                   jmp    0x24
      20:   39 ca                   cmp    %ecx,%edx
      22:   73 37                   jae    0x5b
      24:   4d 8b 39                mov    (%r9),%r15
      27:   83 c7 01                add    $0x1,%edi
      2a:*  49 8b 17                mov    (%r15),%rdx              <-- trapping instruction
      2d:   49 89 11                mov    %rdx,(%r9)
      30:   41 8b 57 28             mov    0x28(%r15),%edx
      34:   45 8b 5f 34             mov    0x34(%r15),%r11d
      38:   49 c7 07 00 00 00 00    movq   $0x0,(%r15)
      3f:   49                      rex.WB

    Code starting with the faulting instruction
    ===========================================
       0:   49 8b 17                mov    (%r15),%rdx
       3:   49 89 11                mov    %rdx,(%r9)
       6:   41 8b 57 28             mov    0x28(%r15),%edx
       a:   45 8b 5f 34             mov    0x34(%r15),%r11d
       e:   49 c7 07 00 00 00 00    movq   $0x0,(%r15)
      15:   49                      rex.WB
    [   70.724561] RSP: 0018:ffff95ae85e6fb90 EFLAGS: 00000202
    [   70.724561] RAX: 0000000002000000 RBX: ffff95ae841de000 RCX: 0000000000000000
    [   70.724561] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
    [   70.724561] RBP: ffff95ae85e6fbf8 R08: 0000000000000000 R09: ffff95b710a30000
    [   70.724561] R10: 0000000000000000 R11: bdf289445ce31881 R12: ffff95ae85e6fc58
    [   70.724561] R13: 0000000000000000 R14: 0000000000000040 R15: 0000000000000000
    [   70.724561] FS:  000000002c5c1380(0000) GS:ffff95bd7fcc0000(0000) knlGS:0000000000000000
    [   70.724561] CS:  0010 DS: 0000 ES: 0000 C
    ---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-2026-005577
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?e3117277");
  # https://lore.kernel.org/linux-cve-announce/2024102129-CVE-2024-49949-c792@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?889aae0c");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2024-49949");
  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-2024-49949");

  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:"2023/12/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/03/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/03/03");

  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:"^20.1070e([^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 && 'sw_64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1070e',
    'pkgs': [
      {'reference':'kernel-4.19.90-2601.1.0.0002', 'sp':'1070e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2601.1.0.0002', 'sp':'1070e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2601.1.0.0002', 'sp':'1070e', 'cpu':'sw_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2601.1.0.0002', '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');
}