Azure Linux 3.0 Security Update: kernel (CVE-2024-41010)

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

include('compat.inc');

if (description)
{
  script_id(295647);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/01/22");

  script_cve_id("CVE-2024-41010");

  script_name(english:"Azure Linux 3.0 Security Update: kernel (CVE-2024-41010)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Azure Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The version of kernel installed on the remote Azure Linux 3.0 host is prior to tested version. It is, therefore,
affected by a vulnerability as referenced in the CVE-2024-41010 advisory.

  - In the Linux kernel, the following vulnerability has been resolved: bpf: Fix too early release of
    tcx_entry Pedro Pinto and later independently also Hyunwoo Kim and Wongi Lee reported an issue that the
    tcx_entry can be released too early leading to a use after free (UAF) when an active old-style ingress or
    clsact qdisc with a shared tc block is later replaced by another ingress or clsact instance. Essentially,
    the sequence to trigger the UAF (one example) can be as follows: 1. A network namespace is created 2. An
    ingress qdisc is created. This allocates a tcx_entry, and &tcx_entry->miniq is stored in the qdisc's
    miniqp->p_miniq. At the same time, a tcf block with index 1 is created. 3. chain0 is attached to the tcf
    block. chain0 must be connected to the block linked to the ingress qdisc to later reach the function
    tcf_chain0_head_change_cb_del() which triggers the UAF. 4. Create and graft a clsact qdisc. This causes
    the ingress qdisc created in step 1 to be removed, thus freeing the previously linked tcx_entry:
    rtnetlink_rcv_msg() => tc_modify_qdisc() => qdisc_create() => clsact_init() [a] => qdisc_graft() =>
    qdisc_destroy() => __qdisc_destroy() => ingress_destroy() [b] => tcx_entry_free() => kfree_rcu() //
    tcx_entry freed 5. Finally, the network namespace is closed. This registers the cleanup_net worker, and
    during the process of releasing the remaining clsact qdisc, it accesses the tcx_entry that was already
    freed in step 4, causing the UAF to occur: cleanup_net() => ops_exit_list() => default_device_exit_batch()
    => unregister_netdevice_many() => unregister_netdevice_many_notify() => dev_shutdown() => qdisc_put() =>
    clsact_destroy() [c] => tcf_block_put_ext() => tcf_chain0_head_change_cb_del() =>
    tcf_chain_head_change_item() => clsact_chain_head_change() => mini_qdisc_pair_swap() // UAF There are also
    other variants, the gist is to add an ingress (or clsact) qdisc with a specific shared block, then to
    replace that qdisc, waiting for the tcx_entry kfree_rcu() to be executed and subsequently accessing the
    current active qdisc's miniq one way or another. The correct fix is to turn the miniq_active boolean into
    a counter. What can be observed, at step 2 above, the counter transitions from 0->1, at step [a] from 1->2
    (in order for the miniq object to remain active during the replacement), then in [b] from 2->1 and finally
    [c] 1->0 with the eventual release. The reference counter in general ranges from [0,2] and it does not
    need to be atomic since all access to the counter is protected by the rtnl mutex. With this in place,
    there is no longer a UAF happening and the tcx_entry is freed at the correct time. (CVE-2024-41010)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2024-41010");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  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-2024-41010");

  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:"2024/07/17");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/08/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/01/22");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:azure_linux:kernel-cross-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:azure_linux:kernel-headers");
  script_set_attribute(attribute:"cpe", value:"x-cpe:/o:microsoft:azure_linux");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Azure 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/AzureLinux/release", "Host/AzureLinux/rpm-list", "Host/cpu");

  exit(0);
}
include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var release = get_kb_item('Host/AzureLinux/release');
if (isnull(release) || 'Azure Linux' >!< release) audit(AUDIT_OS_NOT, 'Azure Linux');
var os_ver = pregmatch(pattern: "Azure Linux ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Azure Linux');
os_ver = os_ver[1];
if (! preg(pattern:"^3([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Azure Linux 3.0', 'Azure Linux ' + os_ver);

if (!get_kb_item('Host/AzureLinux/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu)
  audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Azure Linux', cpu);

var pkgs = [
    {'reference':'kernel-cross-headers-6.6.35.1-5.azl3', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-headers-6.6.35.1-5.azl3', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-headers-6.6.35.1-5.azl3', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var reference = NULL;
  var _release = NULL;
  var sp = NULL;
  var _cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var allowmaj = NULL;
  var exists_check = NULL;
  var cves = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = 'Azure Linux ' + package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) _cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  if (reference && _release && (!exists_check || rpm_exists(release:_release, rpm:exists_check))) {
    if (rpm_check(release:_release, 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-cross-headers / kernel-headers');
}