CVE-2024-42253 – A race condition vulnerability in the Linux ker... (How to Fix)

Q: What is the severity of CVE-2024-42253?

CVE-2024-42253 has a CVSS score of 4.7 (MEDIUM). A race condition vulnerability in the Linux kernel's GPIO PCA953x driver allows concurrent access to interrupt configuration registers, potentially causing incorrect interrupt handling. This affects systems using the PCA953x GPIO expander chip with the vulnerable kernel driver. The issue manifests as occasional system instability during reboots on affected hardware.

📋 TL;DR

A race condition vulnerability in the Linux kernel's GPIO PCA953x driver allows concurrent access to interrupt configuration registers, potentially causing incorrect interrupt handling. This affects systems using the PCA953x GPIO expander chip with the vulnerable kernel driver. The issue manifests as occasional system instability during reboots on affected hardware.

💻 Affected Systems

Products:

Linux kernel with PCA953x GPIO driver

Versions: Kernel versions before the fix commits (specific versions vary by distribution)

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems with PCA953x GPIO expander hardware. The i.MX8MP system mentioned is one example.

📦 What is this software?

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

System crash or kernel panic due to incorrect interrupt handling leading to hardware malfunction or data corruption.

🟠

Likely Case

Occasional system instability, failed reboots, or GPIO interrupt misbehavior requiring manual intervention.

🟢

If Mitigated

Minor performance impact from proper locking with no security or stability issues.

🌐 Internet-Facing: LOW - Requires local access to GPIO hardware and specific timing conditions.

🏢 Internal Only: LOW - Requires physical or privileged access to trigger the race condition.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: HIGH

Exploitation requires precise timing and hardware access. This is a reliability issue rather than a security vulnerability in practice.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing commits 58a5c93bd1a6e949267400080f07e57ffe05ec34 or later

Vendor Advisory: https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution. 2. For Debian/Ubuntu: apt update && apt upgrade linux-image-*. 3. For RHEL/CentOS: yum update kernel. 4. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable PCA953x GPIO if not needed

linux

Remove or blacklist the pca953x kernel module if GPIO expander functionality is not required

echo 'blacklist pca953x' >> /etc/modprobe.d/blacklist.conf
rmmod pca953x

🧯 If You Can't Patch

Ensure proper physical security to prevent unauthorized hardware access
Monitor system logs for GPIO-related errors and implement automated alerting

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if pca953x module is loaded: lsmod | grep pca953x && uname -r

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is patched and check dmesg for GPIO errors after reboot

📡 Detection & Monitoring

Log Indicators:

Kernel messages about GPIO errors
System crash logs during reboot sequences
dmesg output showing PCA953x register access errors

Network Indicators:

None - this is a local hardware/driver issue

SIEM Query:

source="kernel" AND ("pca953x" OR "GPIO" OR "race" OR "interrupt")

📊 Metadata

CVE ID: CVE-2024-42253

CVSS v3 Score: 4.7 (MEDIUM)

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

CWE: CWE-667

Published: August 8, 2024

Last Updated: November 3, 2025

🔗 References

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🔗 Related Vulnerabilities

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