Unity Linux 20.1070e Security Update: kernel (UTSA-2025-990743)

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

include('compat.inc');

if (description)
{
  script_id(275127);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/12");

  script_cve_id("CVE-2023-53143");

  script_name(english:"Unity Linux 20.1070e Security Update: kernel (UTSA-2025-990743)");

  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-2025-990743 advisory.

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

    ext4: fix another off-by-one fsmap error on 1k block filesystems

    Apparently syzbot figured out that issuing this FSMAP call:

    struct fsmap_head cmd = {
            .fmh_count      = ...;
            .fmh_keys       = {
                    { .fmr_device = /* ext4 dev */, .fmr_physical = 0, },
                    { .fmr_device = /* ext4 dev */, .fmr_physical = 0, },
            },
    ...
    };
    ret = ioctl(fd, FS_IOC_GETFSMAP, &cmd);

    Produces this crash if the underlying filesystem is a 1k-block ext4
    filesystem:

    kernel BUG at fs/ext4/ext4.h:3331!
    invalid opcode: 0000 [#1] PREEMPT SMP
    CPU: 3 PID: 3227965 Comm: xfs_io Tainted: G        W  O       6.2.0-rc8-achx
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
    RIP: 0010:ext4_mb_load_buddy_gfp+0x47c/0x570 [ext4]
    RSP: 0018:ffffc90007c03998 EFLAGS: 00010246
    RAX: ffff888004978000 RBX: ffffc90007c03a20 RCX: ffff888041618000
    RDX: 0000000000000000 RSI: 00000000000005a4 RDI: ffffffffa0c99b11
    RBP: ffff888012330000 R08: ffffffffa0c2b7d0 R09: 0000000000000400
    R10: ffffc90007c03950 R11: 0000000000000000 R12: 0000000000000001
    R13: 00000000ffffffff R14: 0000000000000c40 R15: ffff88802678c398
    FS:  00007fdf2020c880(0000) GS:ffff88807e100000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007ffd318a5fe8 CR3: 000000007f80f001 CR4: 00000000001706e0
    Call Trace:
     <TASK>
     ext4_mballoc_query_range+0x4b/0x210 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80]
     ext4_getfsmap_datadev+0x713/0x890 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80]
     ext4_getfsmap+0x2b7/0x330 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80]
     ext4_ioc_getfsmap+0x153/0x2b0 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80]
     __ext4_ioctl+0x2a7/0x17e0 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80]
     __x64_sys_ioctl+0x82/0xa0
     do_syscall_64+0x2b/0x80
     entry_SYSCALL_64_after_hwframe+0x46/0xb0
    RIP: 0033:0x7fdf20558aff
    RSP: 002b:00007ffd318a9e30 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
    RAX: ffffffffffffffda RBX: 00000000000200c0 RCX: 00007fdf20558aff
    RDX: 00007fdf1feb2010 RSI: 00000000c0c0583b RDI: 0000000000000003
    RBP: 00005625c0634be0 R08: 00005625c0634c40 R09: 0000000000000001
    R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdf1feb2010
    R13: 00005625be70d994 R14: 0000000000000800 R15: 0000000000000000

    For GETFSMAP calls, the caller selects a physical block device by
    writing its block number into fsmap_head.fmh_keys[01].fmr_device.
    To query mappings for a subrange of the device, the starting byte of the
    range is written to fsmap_head.fmh_keys[0].fmr_physical and the last
    byte of the range goes in fsmap_head.fmh_keys[1].fmr_physical.

    IOWs, to query what mappings overlap with bytes 3-14 of /dev/sda, you'd
    set the inputs as follows:

            fmh_keys[0] = { .fmr_device = major(8, 0), .fmr_physical = 3},
            fmh_keys[1] = { .fmr_device = major(8, 0), .fmr_physical = 14},

    Which would return you whatever is mapped in the 12 bytes starting at
    physical offset 3.

    The crash is due to insufficient range validation of keys[1] in
    ext4_getfsmap_datadev.  On 1k-block filesystems, block 0 is not part of
    the filesystem, which means that s_first_data_block is nonzero.
    ext4_get_group_no_and_offset subtracts this quantity from the blocknr
    argument before cracking it into a group number and a block number
    within a group.  IOWs, block group 0 spans blocks 1-8192 (1-based)
    instead of 0-8191 (0-based) like what happens with larger blocksizes.

    The net result of this encoding is that blocknr < s_first_data_block is
    not a valid input to this function.  The end_fsb variable is set from
    the keys that are copied from userspace, which means that in the above
    example, its value is zero.  That leads to an underflow here:

            blocknr = blocknr - le32_to_cpu(es->s_first_data_block);

    The division then operates on -1:

            offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)) >>
                    EXT4_SB(sb)->s_cluster_bits;

    Leaving an impossibly large group number (2^32-1) in blocknr.
    ext4_getfsmap_check_keys checked that keys[0
    ---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-2025-990743
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?02c5b660");
  # https://lore.kernel.org/linux-cve-announce/2025050239-CVE-2023-53143-7a2c@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?30e3d204");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2023-53143");
  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-2023-53143");

  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:"2024/06/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/11/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/11/12");

  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');
}