Unity Linux 20.1070e Security Update: kernel (UTSA-2025-989478)

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

include('compat.inc');

if (description)
{
  script_id(272961);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/05");

  script_cve_id("CVE-2024-57896");

  script_name(english:"Unity Linux 20.1070e Security Update: kernel (UTSA-2025-989478)");

  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-2025-989478 advisory.

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

    btrfs: flush delalloc workers queue before stopping cleaner kthread during unmount

    During the unmount path, at close_ctree(), we first stop the cleaner
    kthread, using kthread_stop() which frees the associated task_struct, and
    then stop and destroy all the work queues. However after we stopped the
    cleaner we may still have a worker from the delalloc_workers queue running
    inode.c:submit_compressed_extents(), which calls btrfs_add_delayed_iput(),
    which in turn tries to wake up the cleaner kthread - which was already
    destroyed before, resulting in a use-after-free on the task_struct.

    Syzbot reported this with the following stack traces:

      BUG: KASAN: slab-use-after-free in __lock_acquire+0x78/0x2100 kernel/locking/lockdep.c:5089
      Read of size 8 at addr ffff8880259d2818 by task kworker/u8:3/52

      CPU: 1 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
      Workqueue: btrfs-delalloc btrfs_work_helper
      Call Trace:
       <TASK>
       __dump_stack lib/dump_stack.c:94 [inline]
       dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
       print_address_description mm/kasan/report.c:378 [inline]
       print_report+0x169/0x550 mm/kasan/report.c:489
       kasan_report+0x143/0x180 mm/kasan/report.c:602
       __lock_acquire+0x78/0x2100 kernel/locking/lockdep.c:5089
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
       try_to_wake_up+0xc2/0x1470 kernel/sched/core.c:4205
       submit_compressed_extents+0xdf/0x16e0 fs/btrfs/inode.c:1615
       run_ordered_work fs/btrfs/async-thread.c:288 [inline]
       btrfs_work_helper+0x96f/0xc40 fs/btrfs/async-thread.c:324
       process_one_work kernel/workqueue.c:3229 [inline]
       process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
       worker_thread+0x870/0xd30 kernel/workqueue.c:3391
       kthread+0x2f0/0x390 kernel/kthread.c:389
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
       </TASK>

      Allocated by task 2:
       kasan_save_stack mm/kasan/common.c:47 [inline]
       kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
       unpoison_slab_object mm/kasan/common.c:319 [inline]
       __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
       kasan_slab_alloc include/linux/kasan.h:250 [inline]
       slab_post_alloc_hook mm/slub.c:4104 [inline]
       slab_alloc_node mm/slub.c:4153 [inline]
       kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4205
       alloc_task_struct_node kernel/fork.c:180 [inline]
       dup_task_struct+0x57/0x8c0 kernel/fork.c:1113
       copy_process+0x5d1/0x3d50 kernel/fork.c:2225
       kernel_clone+0x223/0x870 kernel/fork.c:2807
       kernel_thread+0x1bc/0x240 kernel/fork.c:2869
       create_kthread kernel/kthread.c:412 [inline]
       kthreadd+0x60d/0x810 kernel/kthread.c:767
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

      Freed by task 24:
       kasan_save_stack mm/kasan/common.c:47 [inline]
       kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
       kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
       poison_slab_object mm/kasan/common.c:247 [inline]
       __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
       kasan_slab_free include/linux/kasan.h:233 [inline]
       slab_free_hook mm/slub.c:2338 [inline]
       slab_free mm/slub.c:4598 [inline]
       kmem_cache_free+0x195/0x410 mm/slub.c:4700
       put_task_struct include/linux/sched/task.h:144 [inline]
       delayed_put_task_struct+0x125/0x300 kernel/exit.c:227
       rcu_do_batch kernel/rcu/tree.c:2567 [inline]
       rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
       handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:554
       run_ksoftirqd+0xca/0x130 kernel/softirq.c:943

    ---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-2025-989478
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?e76cf954");
  # https://lore.kernel.org/linux-cve-announce/2025011514-CVE-2024-57896-af67@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?e7937205");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2024-57896");
  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-2024-57896");

  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:"2025/01/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/11/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/11/05");

  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) 2025 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 && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1070e',
    'pkgs': [
      {'reference':'kernel-5.10.0-79.4.2', 'sp':'1070e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.4.2', 'sp':'1070e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.4.2', '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');
}