CVE-2024-56595 – This CVE-2024-56595 is an array index out-of-bo... (How to Fix)

Q: What is the severity of CVE-2024-56595?

CVE-2024-56595 has a CVSS score of 7.8 (HIGH). This CVE-2024-56595 is an array index out-of-bounds vulnerability in the JFS filesystem driver in the Linux kernel. An attacker could exploit this to cause a kernel panic (denial of service) or potentially execute arbitrary code with kernel privileges. All Linux systems using the JFS filesystem are affected.

📋 TL;DR

This CVE-2024-56595 is an array index out-of-bounds vulnerability in the JFS filesystem driver in the Linux kernel. An attacker could exploit this to cause a kernel panic (denial of service) or potentially execute arbitrary code with kernel privileges. All Linux systems using the JFS filesystem are affected.

💻 Affected Systems

Products:

Linux kernel with JFS filesystem support

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

Operating Systems: All Linux distributions with JFS support enabled

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if JFS filesystem is mounted or being used. Many distributions don't enable JFS 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...

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 memory corruption leading to arbitrary code execution with root privileges, complete system compromise, or persistent denial of service.

🟠

Likely Case

Kernel panic causing system crash and denial of service, requiring physical or remote console access to reboot.

🟢

If Mitigated

Limited to denial of service if kernel hardening features like KASLR or stack protection are enabled.

🌐 Internet-Facing: LOW - Requires local access or ability to mount JFS filesystems, not typically exposed directly to internet.

🏢 Internal Only: MEDIUM - Local attackers or compromised user accounts could exploit this to escalate privileges or crash systems.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and ability to trigger the dbAdjTree function, likely through filesystem operations on JFS partitions.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Linux kernel with commits 368a533152220b0a6f1142327d96c6b6361f3002 or later

Vendor Advisory: https://git.kernel.org/stable/c/368a533152220b0a6f1142327d96c6b6361f3002

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution. 2. For custom kernels, apply the git commit patches. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable JFS filesystem

linux

Prevent loading of JFS kernel module to eliminate attack surface

echo 'blacklist jfs' >> /etc/modprobe.d/blacklist-jfs.conf
rmmod jfs

Mount JFS as read-only

linux

Mount existing JFS filesystems as read-only to prevent triggering the vulnerability

mount -o remount,ro /path/to/jfs/mountpoint

🧯 If You Can't Patch

Restrict user access to systems with JFS mounts to trusted users only
Implement strict monitoring for kernel panic events and filesystem operations on JFS partitions

🔍 How to Verify

Check if Vulnerable:

Check if JFS module is loaded: lsmod | grep jfs. If loaded and kernel version is unpatched, system is vulnerable.

Check Version:

uname -r

Verify Fix Applied:

Check kernel version includes fix commits: uname -r and verify with distribution patch notes. Ensure JFS module version matches patched kernel.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/kern.log or dmesg
Filesystem corruption errors related to JFS

Network Indicators:

Sudden loss of connectivity to system (if crash occurs)

SIEM Query:

source="kernel" AND ("panic" OR "Oops" OR "BUG") AND "jfs"

📊 Metadata

CVE ID: CVE-2024-56595

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-129

Published: December 27, 2024

Last Updated: November 3, 2025

🔗 References

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2024-56595, you might also want to check these: