CVE-2023-53346 – This CVE describes a memory leak vulnerability ... (How to Fix)

Q: What is the severity of CVE-2023-53346?

CVE-2023-53346 has a CVSS score of 5.5 (MEDIUM). This CVE describes a memory leak vulnerability in the Linux kernel's fail_function module where debugfs_lookup() is called without properly releasing memory using dput(). This allows attackers to gradually exhaust system memory over time, potentially leading to denial of service. All Linux systems using affected kernel versions are vulnerable.

📋 TL;DR

This CVE describes a memory leak vulnerability in the Linux kernel's fail_function module where debugfs_lookup() is called without properly releasing memory using dput(). This allows attackers to gradually exhaust system memory over time, potentially leading to denial of service. All Linux systems using affected kernel versions are vulnerable.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE, but patches available for multiple stable branches

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires the fail_function module to be loaded/used, which may not be enabled in all configurations

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

System memory exhaustion leading to kernel panic, system crash, or denial of service affecting all running processes

🟠

Likely Case

Gradual memory consumption over time causing performance degradation and potential application failures

🟢

If Mitigated

Minimal impact with proper memory monitoring and resource limits in place

🌐 Internet-Facing: LOW - Requires local access or ability to trigger the specific kernel function

🏢 Internal Only: MEDIUM - Local users or processes could exploit this to degrade system performance

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires ability to trigger the vulnerable debugfs_lookup() function in the fail_function module

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Multiple stable kernel versions with commits referenced in CVE

Vendor Advisory: https://git.kernel.org/stable/c/29d53c4c5a6f6d2b93aaac95b65cb4c907faf2ff

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.

🔧 Temporary Workarounds

Disable fail_function module

all

Prevent loading of the vulnerable kernel module

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

🧯 If You Can't Patch

Implement strict memory limits and monitoring to detect abnormal memory consumption
Restrict access to debugfs interface and limit which users can interact with kernel modules

🔍 How to Verify

Check if Vulnerable:

Check if fail_function module is loaded: lsmod | grep fail_function

Check Version:

uname -r

Verify Fix Applied:

Check kernel version against patched versions and verify fail_function module behavior

📡 Detection & Monitoring

Log Indicators:

Kernel OOM (Out of Memory) messages in dmesg or syslog
Abnormal memory consumption patterns in system monitoring

Network Indicators:

None - this is a local kernel vulnerability

SIEM Query:

source="kernel" AND ("out of memory" OR "OOM" OR "memory allocation failure")

📊 Metadata

CVE ID: CVE-2023-53346

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-401

EPSS Score: 0.01% exploit probability (1.5th percentile)

Published: September 17, 2025

Last Updated: January 14, 2026

🔗 References

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