Cloudanix VulnDB

CVE-2026-68182

None

CVSS

—

EPSS

0.2%

Published

Aug 10, 2026

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A bug in a Linux kernel driver for parallel-port data acquisition hardware can cause the whole system to crash if an interrupt arrives before the driver is fully ready.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Race Condition
Remediation
Patch
Effort
Low
Patch risk
Low

What it actually does

Race condition allowing premature interrupt delivery in comedi_parport before subdevice allocation completes or with invalid I/O port base, resulting in general protection fault inside comedi_get_is_subdevice_running called from parport_interrupt.

Why it matters to the business

Kernel panic or system instability on hosts using the comedi_parport driver for data acquisition hardware, potentially causing downtime for specialized industrial or scientific workloads.

How an attack unfolds

An attacker with local access supplies an invalid I/O port base address during driver attach or relies on timing to fire an interrupt before subdevices exist; the handler dereferences uninitialized structures, triggering the fault. No named threat actors or ransomware campaigns are associated.

How to fix it

Update the Linux kernel to a version containing the reordered initialization in parport_attach (hardware setup before request_irq) plus the early-return check in parport_interrupt that verifies the comedi device is fully attached.

How to confirm the fix worked

Confirm the presence of the initialization-order change and the added 'device fully attached' guard in the parport_interrupt handler; test attach with both valid and invalid port bases to verify no premature faults occur.

Typical attack path

  1. Load or trigger attach of the comedi_parport driver with a user-supplied or fuzzed I/O port base
  2. Interrupt fires before parport_attach finishes hardware register setup and subdevice allocation
  3. parport_interrupt calls comedi_get_is_subdevice_running on an incompletely initialized comedi device
  4. General protection fault occurs, crashing the kernel

How to detect it

Search kernel logs and crash dumps for general protection faults originating in comedi_get_is_subdevice_running or parport_interrupt; inspect dmesg for comedi_parport attach sequences that precede the fault.

  • comedi_get_is_subdevice_running
  • parport_interrupt
  • comedi_parport
  • general protection fault

What your security team should do

  • Apply the upstream fix to any kernel trees that include the comedi_parport driver
  • Disable the driver module if the hardware is not required
  • Monitor kernel logs for general protection faults referencing comedi_get_is_subdevice_running or parport_interrupt

The record

In the Linux kernel, the following vulnerability has been resolved: comedi: comedi_parport: deal with premature interrupt Syzbot reported a general protection fault in `comedi_get_is_subdevice_running()`, which was called from the interrupt handler `parport_interrupt()` in the "comedi_parport" driver, but it does not currently have a C reproducer for the problem. It's probably due to a premature interrupt for one of two reasons: 1. The driver sets up the interrupt handler before the comedi subdevices used by the interrupt handler have been allocated, but does not disable the interrupt in the parallel port's CTRL register first. 2. The driver uses a user-supplied I/O port base address which Syzbot would have supplied, but it might not be backed by real parallel port hardware. Change the initialization order in the driver's comedi "attach" handler (`parport_attach()`) so that the hardware registers are initialized before the interrupt handler is requested. This should prevent premature interrupts occurring for real hardware. Also add a test to the interrupt handler to ensure the comedi device is fully attached and return early if it isn't.

Affected packages

Ecosystem Package Introduced Fixed