CVE-2025-38668 – A NULL pointer dereference vulnerability in the... (How to Fix)

Q: What is the severity of CVE-2025-38668?

CVE-2025-38668 has a CVSS score of 5.5 (MEDIUM). A NULL pointer dereference vulnerability in the Linux kernel's regulator subsystem can cause kernel panics when accessing regulator coupling data after device unbind. This affects systems using the regulator framework for power management, particularly during runtime PM operations. The vulnerability requires local access to trigger.

📋 TL;DR

A NULL pointer dereference vulnerability in the Linux kernel's regulator subsystem can cause kernel panics when accessing regulator coupling data after device unbind. This affects systems using the regulator framework for power management, particularly during runtime PM operations. The vulnerability requires local access to trigger.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not specified in CVE, but references indicate stable kernel patches

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires use of regulator framework and coupling functionality; triggered by unbinding regulator devices.

📦 What is this software?

Debian Linux by Debian

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Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

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Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

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Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, potentially causing data loss or service disruption.

🟠

Likely Case

System crash or instability when unbinding regulator devices during runtime power management operations.

🟢

If Mitigated

No impact if the vulnerable code path is not triggered through regulator operations post-unbind.

🌐 Internet-Facing: LOW - Requires local access to trigger through regulator operations.

🏢 Internal Only: MEDIUM - Local users or processes with appropriate permissions could trigger the crash.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and ability to trigger regulator operations; not remotely exploitable.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patched in stable kernel commits referenced in CVE

Vendor Advisory: https://git.kernel.org/stable/c/233d3c54c9620e95193923859ea1d0b0f5d748ca

Restart Required: Yes

Instructions:

1. Update to a patched kernel version from your distribution vendor. 2. Apply the specific kernel patch if building from source. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Avoid regulator device unbinding

all

Prevent triggering the vulnerability by avoiding unbinding of regulator platform devices during runtime.

🧯 If You Can't Patch

Restrict local access to prevent users from triggering regulator operations
Monitor system logs for regulator-related crashes and investigate any unbinding operations

🔍 How to Verify

Check if Vulnerable:

Check kernel version and compare with patched versions from distribution vendor; examine if regulator coupling is used.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated to a version containing the fix; test regulator unbinding operations if possible.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
NULL pointer dereference errors in dmesg
regulator-related crash logs

Network Indicators:

None - local vulnerability only

SIEM Query:

Search for kernel panic events or NULL pointer dereference errors in system logs

📊 Metadata

CVE ID: CVE-2025-38668

CVSS v3 Score: 5.5 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-476

EPSS Score: 0.02% exploit probability (6.1th percentile)

Published: August 22, 2025

Last Updated: January 8, 2026

🔗 References

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