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AlmaLinux 9.2 [TuxCare] Security Update: bpftool / kernel / kernel-abi-stablelists / kernel-core / etc Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2025:1757699471)

🗓️ 01 Oct 2026 00:00:00Reported by TenableType 
nessus
 nessus
🔗 www.tenable.com👁 4 Views

Memory accounting leak and integer overflow in AlmaLinux 9.2 Linux kernel udp.

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

include('compat.inc');

if (description)
{
  script_id(360814);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/02");

  script_cve_id(
    "CVE-2025-22058",
    "CVE-2025-37823",
    "CVE-2025-37914",
    "CVE-2025-38000",
    "CVE-2025-38084",
    "CVE-2025-38124",
    "CVE-2025-38177",
    "CVE-2025-38200",
    "CVE-2025-38211",
    "CVE-2025-38350",
    "CVE-2025-38352",
    "CVE-2025-38461",
    "CVE-2025-38464"
  );
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2025/09/25");
  script_xref(name:"CLSA", value:"2025:1757699471");

  script_name(english:"AlmaLinux 9.2 [TuxCare] Security Update: bpftool / kernel / kernel-abi-stablelists / kernel-core / etc Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2025:1757699471)");

  script_set_attribute(attribute:"synopsis", value:
"The AlmaLinux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The AlmaLinux 9.2 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare
ALMALINUX9.2:CLSA-2025:1757699471 advisory.

  - In the Linux kernel, the following vulnerability has been resolved: udp: Fix memory accounting leak. Matt
    Dowling reported a weird UDP memory usage issue. Under normal operation, the UDP memory usage reported in
    /proc/net/sockstat remains close to zero. However, it occasionally spiked to 524,288 pages and never
    dropped. Moreover, the value doubled when the application was terminated. Finally, it caused intermittent
    packet drops. We can reproduce the issue with the script below [0]: 1. /proc/net/sockstat reports 0 pages
    # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 0 2. Run the script till the report reaches 524,288
    # python3 test.py & sleep 5 # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 524288 <-- (INT_MAX + 1)
    >> PAGE_SHIFT 3. Kill the socket and confirm the number never drops # pkill python3 && sleep 5 # cat
    /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 524288 4. (necessary since v6.0) Trigger
    proto_memory_pcpu_drain() # python3 test.py & sleep 1 && pkill python3 5. The number doubles # cat
    /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 1048577 The application set INT_MAX to SO_RCVBUF, which
    triggered an integer overflow in udp_rmem_release(). When a socket is close()d, udp_destruct_common()
    purges its receive queue and sums up skb->truesize in the queue. This total is calculated and stored in a
    local unsigned integer variable. The total size is then passed to udp_rmem_release() to adjust memory
    accounting. However, because the function takes a signed integer argument, the total size can wrap around,
    causing an overflow. Then, the released amount is calculated as follows: 1) Add size to
    sk->sk_forward_alloc. 2) Round down sk->sk_forward_alloc to the nearest lower multiple of PAGE_SIZE and
    assign it to amount. 3) Subtract amount from sk->sk_forward_alloc. 4) Pass amount >> PAGE_SHIFT to
    __sk_mem_reduce_allocated(). When the issue occurred, the total in udp_destruct_common() was 2147484480
    (INT_MAX + 833), which was cast to -2147482816 in udp_rmem_release(). At 1) sk->sk_forward_alloc is
    changed from 3264 to -2147479552, and 2) sets -2147479552 to amount. 3) reverts the wraparound, so we
    don't see a warning in inet_sock_destruct(). However, udp_memory_allocated ends up doubling at 4). Since
    commit 3cd3399dd7a8 (net: implement per-cpu reserves for memory_allocated), memory usage no longer
    doubles immediately after a socket is close()d because __sk_mem_reduce_allocated() caches the amount in
    udp_memory_per_cpu_fw_alloc. However, the next time a UDP socket receives a packet, the subtraction takes
    effect, causing UDP memory usage to double. This issue makes further memory allocation fail once the
    socket's sk->sk_rmem_alloc exceeds net.ipv4.udp_rmem_min, resulting in packet drops. To prevent this
    issue, let's use unsigned int for the calculation and call sk_forward_alloc_add() only once for the small
    delta. Note that first_packet_length() also potentially has the same problem. [0]: from socket import *
    SO_RCVBUFFORCE = 33 INT_MAX = (2 ** 31) - 1 s = socket(AF_INET, SOCK_DGRAM) s.bind(('', 0))
    s.setsockopt(SOL_SOCKET, SO_RCVBUFFORCE, INT_MAX) c = socket(AF_INET, SOCK_DGRAM)
    c.connect(s.getsockname()) data = b'a' * 100 while True: c.send(data) (CVE-2025-22058)

  - In the Linux kernel, the following vulnerability has been resolved: net_sched: hfsc: Fix a potential UAF
    in hfsc_dequeue() too Similarly to the previous patch, we need to safe guard hfsc_dequeue() too. But for
    this one, we don't have a reliable reproducer. (CVE-2025-37823)

  - In the Linux kernel, the following vulnerability has been resolved: net_sched: ets: Fix double list add in
    class with netem as child qdisc As described in Gerrard's report [1], there are use cases where a netem
    child qdisc will make the parent qdisc's enqueue callback reentrant. In the case of ets, there won't be a
    UAF, but the code will add the same classifier to the list twice, which will cause memory corruption. In
    addition to checking for qlen being zero, this patch checks whether the class was already added to the
    active_list (cl_is_active) before doing the addition to cater for the reentrant case. [1]
    https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/
    (CVE-2025-37914)

  - In the Linux kernel, the following vulnerability has been resolved: sch_hfsc: Fix qlen accounting bug when
    using peek in hfsc_enqueue() When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls the
    child qdisc's peek() operation before incrementing sch->q.qlen and sch->qstats.backlog. If the child qdisc
    uses qdisc_peek_dequeued(), this may trigger an immediate dequeue and potential packet drop. In such
    cases, qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backlog have not yet been
    updated, leading to inconsistent queue accounting. This can leave an empty HFSC class in the active list,
    causing further consequences like use-after-free. This patch fixes the bug by moving the increment of
    sch->q.qlen and sch->qstats.backlog before the call to the child qdisc's peek() operation. This ensures
    that queue length and backlog are always accurate when packet drops or dequeues are triggered during the
    peek. (CVE-2025-38000)

  - In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: unshare page tables during
    VMA split, not before Currently, __split_vma() triggers hugetlb page table unsharing through
    vm_ops->may_split(). This happens before the VMA lock and rmap locks are taken - which is too early, it
    allows racing VMA-locked page faults in our process and racing rmap walks from other processes to cause
    page tables to be shared again before we actually perform the split. Fix it by explicitly calling into the
    hugetlb unshare logic from __split_vma() in the same place where THP splitting also happens. At that
    point, both the VMA and the rmap(s) are write-locked. An annoying detail is that we can now call into the
    helper hugetlb_unshare_pmds() from two different locking contexts: 1. from hugetlb_split(), holding: -
    mmap lock (exclusively) - VMA lock - file rmap lock (exclusively) 2. hugetlb_unshare_all_pmds(), which I
    think is designed to be able to call us with only the mmap lock held (in shared mode), but currently only
    runs while holding mmap lock (exclusively) and VMA lock Backporting note: This commit fixes a racy
    protection that was introduced in commit b30c14cd6102 (hugetlb: unshare some PMDs when splitting VMAs);
    that commit claimed to fix an issue introduced in 5.13, but it should actually also go all the way back.
    [[email protected]: v2] (CVE-2025-38084)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://security.tuxcare.com/csaf/v2/els_os/almalinux9.2esu/advisories/2025/clsa-2025_1757699471.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?665258d5");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2025:1757699471");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.2:CLSA-2025:1757699471.");
  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:H/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:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2025-38464");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");
  script_set_attribute(attribute:"vendor_severity", value:"Important");

  script_set_attribute(attribute:"vuln_publication_date", value:"2025/02/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/09/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/01");

  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:"Alma 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/OS/extended-third-party", "Host/local_checks_enabled", "Host/AlmaLinux/release", "Host/AlmaLinux/rpm-list", "Host/cpu");

  exit(0);
}
include('rpm2.inc');

var third_party_support = get_kb_item('Host/OS/extended-third-party');
if (empty_or_null(third_party_support) || third_party_support != 'TuxCare') exit(0, 'TuxCare support not enabled.');

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) || 'AlmaLinux' >!< os_product) audit(AUDIT_OS_NOT, 'AlmaLinux');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'AlmaLinux');
if (! preg(pattern:"^9.2([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'AlmaLinux 9.2', 'AlmaLinux ' + os_version);

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

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


var constraints = [
  {
    'release': '9',
    'sp': '2',
    'pkgs': [
      {'reference':'bpftool-7.0.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-abi-stablelists-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-core-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-cross-headers-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-core-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-devel-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-devel-matched-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-modules-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-modules-core-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-modules-extra-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-modules-internal-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-modules-partner-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-uki-virt-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-devel-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-devel-matched-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-headers-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-ipaclones-internal-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-modules-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-modules-core-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-modules-extra-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-modules-internal-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-modules-partner-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-selftests-internal-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-libs-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-tools-libs-devel-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-uki-virt-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'libbpf-1.0.0-2.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'libbpf-1.0.0-2.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'libbpf-devel-1.0.0-2.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'libbpf-devel-1.0.0-2.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'libbpf-static-1.0.0-2.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'libbpf-static-1.0.0-2.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'perf-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-perf-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rtla-5.14.0-284.1101.el9_2.tuxcare.7.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', '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, 'bpftool / kernel / kernel-abi-stablelists / kernel-core / etc');
}

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02 Oct 2026 00:00Current
6.3Medium risk
Vulners AI Score6.3
CVSS 3.17.8 - 9.8
EPSS0.01289
SSVC
4