CVE-2026-89769

Received Received - Intake

IRQ Leak in NXP PIT Clocksource Driver

Publication date: 2026-09-11

Last updated on: 2026-09-13

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: clocksource/drivers/nxp-pit: Fix IRQ leak on cpuhp_setup_state error path When cpuhp_setup_state fails after pit_clockevent_per_cpu_init has successfully called request_irq, the error handling jumps directly to out_pit_clocksource_unregister without freeing the registered IRQ. This leaks the IRQ line and, since kfree(pit) follows, leaves a dangling pointer registered as the interrupt handler's dev_id, potentially leading to a use-after-free if the IRQ fires afterwards. Fix it by calling pit_clockevent_per_cpu_exit to properly release the IRQ before falling through to the existing cleanup chain.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-11

Last Modified

2026-09-13

Generated

2026-10-02

AI Q&A

2026-09-12

EPSS Evaluated

2026-10-01

NVD

CVE-2026-89769

EUVD

EUVD-2026-76681

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is a Linux kernel vulnerability where an IRQ (interrupt request) is not properly freed when an error occurs during CPU hotplug state setup. The issue happens in the NXP PIT (Periodic Interrupt Timer) clocksource driver. When a specific setup function fails after requesting an IRQ, the cleanup process skips freeing that IRQ, leading to a resource leak. Additionally, a dangling pointer may remain, which could cause a use-after-free if the IRQ triggers later.

Detection Guidance

This vulnerability is specific to the Linux kernel's NXP PIT clocksource driver and does not have network-based detection methods. Detection requires checking kernel logs for IRQ-related errors or inspecting the driver's initialization state. Use commands like dmesg | grep -i pit or journalctl -k | grep -i pit to review kernel logs for IRQ leaks or failed cpuhp_setup_state calls.

Impact Analysis

This vulnerability could lead to system instability or crashes if the leaked IRQ triggers a use-after-free condition. It may cause unexpected behavior, kernel panics, or security issues due to improper resource management. Systems relying on the NXP PIT clocksource driver could experience these problems.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a Linux kernel IRQ leak issue that could lead to system instability or crashes but does not involve data breaches or unauthorized access to sensitive information.

Mitigation Strategies

Apply the kernel patch that fixes the IRQ leak in the NXP PIT driver. Update your Linux kernel to a version containing the fix. If immediate patching is not possible, disable the NXP PIT clocksource driver by adding clocksource=pit to the kernel command line during boot.

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