CVE-2024-56630 – A memory leak vulnerability in the Linux kernel... (How to Fix)

Q: What is the severity of CVE-2024-56630?

CVE-2024-56630 has a CVSS score of 5.5 (MEDIUM). A memory leak vulnerability in the Linux kernel's OCFS2 filesystem driver occurs when dquot_initialize() fails after new_inode() succeeds, causing busy inodes to remain after unmount. This affects Linux systems using the OCFS2 filesystem. Attackers could potentially exploit this to cause denial of service or resource exhaustion.

📋 TL;DR

A memory leak vulnerability in the Linux kernel's OCFS2 filesystem driver occurs when dquot_initialize() fails after new_inode() succeeds, causing busy inodes to remain after unmount. This affects Linux systems using the OCFS2 filesystem. Attackers could potentially exploit this to cause denial of service or resource exhaustion.

💻 Affected Systems

Products:

Linux kernel with OCFS2 filesystem support

Versions: Linux kernel versions containing commit 9c89fe0af826 up to patched versions

Operating Systems: Linux distributions with OCFS2 support enabled

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if OCFS2 filesystem is actually used. Most Linux distributions don't enable OCFS2 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

System crash or kernel panic due to resource exhaustion, potentially leading to denial of service and data corruption in OCFS2 filesystems.

🟠

Likely Case

Memory leak causing gradual performance degradation, filesystem corruption, or inability to unmount OCFS2 filesystems properly.

🟢

If Mitigated

Minor performance impact with proper monitoring and restart procedures in place.

🌐 Internet-Facing: LOW - Requires local filesystem access and OCFS2 usage, not directly network exploitable.

🏢 Internal Only: MEDIUM - Internal users with OCFS2 access could potentially trigger the condition, but requires specific filesystem operations.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and ability to trigger specific OCFS2 filesystem operations that cause dquot_initialize() to fail.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patched in stable kernel versions via commits listed in references

Vendor Advisory: https://git.kernel.org/stable/c/03db61c43c8e2729896fda6b9a95c7fb5c875c20

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify OCFS2 filesystems mount correctly.

🔧 Temporary Workarounds

Disable OCFS2 module

linux

Prevent loading of OCFS2 kernel module if not needed

echo 'blacklist ocfs2' >> /etc/modprobe.d/blacklist.conf
rmmod ocfs2

Avoid OCFS2 usage

linux

Use alternative filesystems instead of OCFS2

🧯 If You Can't Patch

Monitor system memory usage and OCFS2 filesystem health regularly
Implement strict access controls to limit who can create/modify OCFS2 filesystems

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if OCFS2 module is loaded: uname -r && lsmod | grep ocfs2

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is patched and test OCFS2 operations that previously triggered the condition

📡 Detection & Monitoring

Log Indicators:

Kernel logs showing 'busy inodes after unmount'
Memory leak warnings in system logs
OCFS2 filesystem mount/unmount errors

Network Indicators:

None - local filesystem issue

SIEM Query:

source="kernel" AND ("busy inodes" OR "ocfs2" AND error)

📊 Metadata

CVE ID: CVE-2024-56630

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-908

Published: December 27, 2024

Last Updated: November 3, 2025

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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