CVE-2024-26981 – This CVE describes an out-of-bounds (OOB) read ... (How to Fix)

Q: What is the severity of CVE-2024-26981?

CVE-2024-26981 has a CVSS score of 7.8 (HIGH). This CVE describes an out-of-bounds (OOB) read vulnerability in the Linux kernel's nilfs2 filesystem driver. When a specially crafted filesystem is mounted, an attacker could trigger memory corruption leading to kernel panic or potential privilege escalation. This affects Linux systems using the nilfs2 filesystem.

📋 TL;DR

This CVE describes an out-of-bounds (OOB) read vulnerability in the Linux kernel's nilfs2 filesystem driver. When a specially crafted filesystem is mounted, an attacker could trigger memory corruption leading to kernel panic or potential privilege escalation. This affects Linux systems using the nilfs2 filesystem.

💻 Affected Systems

Products:

Linux kernel

Versions: Linux kernel versions with nilfs2 support before the fix commits

Operating Systems: Linux distributions with nilfs2 support enabled

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if nilfs2 filesystem support is compiled into the kernel (not all distributions enable this by default).

📦 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 memory corruption leading to system crash (denial of service) or potential local privilege escalation to root.

🟠

Likely Case

System crash or kernel panic when accessing malicious nilfs2 filesystem, causing denial of service.

🟢

If Mitigated

Limited impact if nilfs2 filesystem is not used or access is restricted.

🌐 Internet-Facing: LOW - Requires local access or ability to mount malicious filesystem.

🏢 Internal Only: MEDIUM - Local users could exploit to crash system or potentially escalate privileges.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires ability to mount or access a malicious nilfs2 filesystem. Local access needed.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Linux kernel with commits 054f29e9ca05be3906544c5f2a2c7321c30a4243 or later

Vendor Advisory: https://git.kernel.org/stable/c/054f29e9ca05be3906544c5f2a2c7321c30a4243

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix. 2. Reboot system to load new kernel. 3. Verify nilfs2 module is not loaded if not needed.

🔧 Temporary Workarounds

Disable nilfs2 module

linux

Prevent loading of nilfs2 kernel module to mitigate vulnerability

echo 'install nilfs2 /bin/false' >> /etc/modprobe.d/disable-nilfs2.conf
rmmod nilfs2

Restrict filesystem mounting

linux

Prevent mounting of nilfs2 filesystems via /etc/fstab or mount restrictions

chmod 000 /sbin/mount.nilfs2
chmod 000 /sbin/fsck.nilfs2

🧯 If You Can't Patch

Disable nilfs2 kernel module loading via modprobe blacklist
Implement strict access controls to prevent untrusted users from mounting filesystems

🔍 How to Verify

Check if Vulnerable:

Check if nilfs2 module is loaded: lsmod | grep nilfs2. If loaded and kernel version is before fix, system is vulnerable.

Check Version:

uname -r

Verify Fix Applied:

Check kernel version includes fix commit: uname -r and verify with distribution patch notes. Ensure nilfs2 module is not loaded or updated.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
OOB memory access errors in kernel logs
Failed nilfs2 mount attempts

Network Indicators:

None - local filesystem vulnerability

SIEM Query:

source="kernel" AND ("nilfs2" OR "OOB" OR "out of bounds")

📊 Metadata

CVE ID: CVE-2024-26981

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: May 1, 2024

Last Updated: November 4, 2025

🔗 References

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