CVE-2024-26734 – This CVE describes a use-after-free and memory ... (How to Fix)

Q: What is the severity of CVE-2024-26734?

CVE-2024-26734 has a CVSS score of 7.8 (HIGH). This CVE describes a use-after-free and memory leak vulnerability in the Linux kernel's devlink subsystem initialization function. Attackers could potentially exploit this to cause kernel crashes, memory corruption, or denial of service. Systems running vulnerable Linux kernel versions with devlink enabled are affected.

📋 TL;DR

This CVE describes a use-after-free and memory leak vulnerability in the Linux kernel's devlink subsystem initialization function. Attackers could potentially exploit this to cause kernel crashes, memory corruption, or denial of service. Systems running vulnerable Linux kernel versions with devlink enabled are affected.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE description; check kernel commit history for exact range.

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable when devlink subsystem is enabled/used. Many distributions may not have this enabled by default.

📦 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...

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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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, potentially allowing privilege escalation if combined with other vulnerabilities.

🟠

Likely Case

System instability, kernel crashes, or denial of service affecting network management functionality.

🟢

If Mitigated

Limited impact if devlink is not used or system has proper isolation and monitoring.

🌐 Internet-Facing: LOW - Requires local access or specific network configuration to trigger.

🏢 Internal Only: MEDIUM - Local users or processes could potentially trigger the vulnerability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: HIGH

Exploitation requires triggering specific initialization failure conditions during devlink subsystem setup.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing commits: 919092bd5482b7070ae66d1daef73b600738f3a2, def689fc26b9a9622d2e2cb0c4933dd3b1c8071c, e91d3561e28d7665f4f837880501dc8755f635a9

Vendor Advisory: https://git.kernel.org/stable/c/919092bd5482b7070ae66d1daef73b600738f3a2

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version. 2. Check distribution-specific security advisories. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable devlink module

linux

Prevent loading of devlink kernel module if not required

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

🧯 If You Can't Patch

Ensure devlink module is not loaded or disable it via kernel parameters
Implement strict access controls to prevent local users from triggering devlink initialization

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if devlink module is loaded: 'uname -r' and 'lsmod | grep devlink'

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated and check for presence of fix commits in kernel source

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
OOM (Out of Memory) errors
devlink initialization failures in kernel logs

Network Indicators:

Unusual devlink-related network traffic if applicable

SIEM Query:

source="kernel" AND ("panic" OR "devlink" OR "use-after-free")

📊 Metadata

CVE ID: CVE-2024-26734

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-401

Published: April 3, 2024

Last Updated: January 14, 2025

🔗 References

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🔗 Related Vulnerabilities

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