Linux Distros Unpatched Vulnerability : CVE-2026-46031

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

include('compat.inc');

if (description)
{
  script_id(317169);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/02");

  script_cve_id("CVE-2026-46031");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-46031");

  script_set_attribute(attribute:"synopsis", value:
"The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be
patched.");
  script_set_attribute(attribute:"description", value:
"The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied
patch available.

  - net: ks8851: Reinstate disabling of BHs around IRQ handler If the driver executes ks8851_irq() AND a TX
    packet has been sent, then the driver enables TX queue via netif_wake_queue() which schedules TX softirq
    to queue packets for this device. If CONFIG_PREEMPT_RT=y is set AND a packet has also been received by the
    MAC, then ks8851_rx_pkts() calls netdev_alloc_skb_ip_align() to allocate SKBs for the received packets. If
    netdev_alloc_skb_ip_align() is called with BH enabled, then local_bh_enable() at the end of
    netdev_alloc_skb_ip_align() will trigger the pending softirq processing, which may ultimately call the
    .xmit callback ks8851_start_xmit_par(). The ks8851_start_xmit_par() will try to lock struct ks8851_net_par
    .lock spinlock, which is already locked by ks8851_irq() from which ks8851_start_xmit_par() was called.
    This leads to a deadlock, which is reported by the kernel, including a trace listed below. If
    CONFIG_PREEMPT_RT is not set, then since commit 0913ec336a6c0 (net: ks8851: Fix deadlock with the SPI
    chip variant) the deadlock can also be triggered without received packet in the RX FIFO. The pending
    softirqs will be processed on return from spin_unlock_bh(&ks->statelock) in ks8851_irq(), which triggers
    the deadlock as well. Fix the problem by disabling BH around critical sections, including the IRQ handler,
    thus preventing the net_tx_action() softirq from triggering during these critical sections. The
    net_tx_action() softirq is triggered once BH are re-enabled and at the end of the IRQ handler, once all
    the other IRQ handler actions have been completed. __schedule from schedule_rtlock+0x1c/0x34
    schedule_rtlock from rtlock_slowlock_locked+0x548/0x904 rtlock_slowlock_locked from rt_spin_lock+0x60/0x9c
    rt_spin_lock from ks8851_start_xmit_par+0x74/0x1a8 ks8851_start_xmit_par from netdev_start_xmit+0x20/0x44
    netdev_start_xmit from dev_hard_start_xmit+0xd0/0x188 dev_hard_start_xmit from sch_direct_xmit+0xb8/0x25c
    sch_direct_xmit from __qdisc_run+0x1f8/0x4ec __qdisc_run from qdisc_run+0x1c/0x28 qdisc_run from
    net_tx_action+0x1f0/0x268 net_tx_action from handle_softirqs+0x1a4/0x270 handle_softirqs from
    __local_bh_enable_ip+0xcc/0xe0 __local_bh_enable_ip from __alloc_skb+0xd8/0x128 __alloc_skb from
    __netdev_alloc_skb+0x3c/0x19c __netdev_alloc_skb from ks8851_irq+0x388/0x4d4 ks8851_irq from
    irq_thread_fn+0x24/0x64 irq_thread_fn from irq_thread+0x178/0x28c irq_thread from kthread+0x12c/0x138
    kthread from ret_from_fork+0x14/0x28 (CVE-2026-46031)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-46031");
  script_set_attribute(attribute:"solution", value:
"There is no known solution at this time.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-46031");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_set_attribute(attribute:"vendor_unpatched", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/05/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/05/27");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:linux");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  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", "set_linux_os_id.nasl");
  script_require_keys("Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched", "Host/OS/identifier");
  script_require_ports("Host/OS/Debian Linux-12");

  exit(0);
}

if (!get_kb_item("global_settings/vendor_unpatched")) exit(0, "Unpatched Vulnerabilities Detection not active.");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (empty_or_null(get_one_kb_item("Host/Debian/dpkg-l"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "btrfs-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "cdrom-core-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "ext4-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "fat-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "isofs-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "jfs-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "kernel-image-6.1.0-47-alpha-generic-di"},
          {"reference": "linux-doc"},
          {"reference": "linux-doc-6.1"},
          {"reference": "linux-headers-6.1.0"},
          {"reference": "linux-source"},
          {"reference": "linux-source-6.1"},
          {"reference": "linux-support-6.1.0"},
          {"reference": "loop-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "nic-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "nic-shared-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "nic-wireless-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "pata-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "ppp-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "scsi-core-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "scsi-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "scsi-nic-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "serial-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "usb-serial-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "xfs-modules-6.1.0-47-alpha-generic-di"}
        ]
      }
    ]
  }
};

var distro_constraints_values = linux_unpatched::get_distro_constraints(distro_constraints_arr:distro_constraints_array);
if (empty_or_null(distro_constraints_values)) audit(AUDIT_HOST_NOT, 'affected');
var report = linux_unpatched::check_unpatched_constraints(distro_constraints_values:distro_constraints_values);

if (!empty_or_null(report))
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}