CVE-2022-49255 – This CVE-2022-49255 is a Linux kernel vulnerabi... (How to Fix)

Q: What is the severity of CVE-2022-49255?

CVE-2022-49255 has a CVSS score of 5.5 (MEDIUM). This CVE-2022-49255 is a Linux kernel vulnerability in the F2FS filesystem where the f2fs_handle_failed_inode function fails to properly free node IDs (nids) during error handling. This can lead to kernel panic (system crash) when unmounting filesystems, affecting systems using F2FS filesystem. The vulnerability requires local access to trigger.

📋 TL;DR

This CVE-2022-49255 is a Linux kernel vulnerability in the F2FS filesystem where the f2fs_handle_failed_inode function fails to properly free node IDs (nids) during error handling. This can lead to kernel panic (system crash) when unmounting filesystems, affecting systems using F2FS filesystem. The vulnerability requires local access to trigger.

💻 Affected Systems

Products:

Linux kernel with F2FS filesystem support

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

Operating Systems: Linux distributions with vulnerable kernel versions

Default Config Vulnerable: ✅ No

Notes: Only affects systems using F2FS filesystem. Many distributions don't enable F2FS 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, potentially causing data corruption or loss on affected filesystems.

🟠

Likely Case

System crash during filesystem unmount operations, requiring reboot and potentially causing service disruption.

🟢

If Mitigated

No impact if patched or if F2FS filesystem is not in use.

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

🏢 Internal Only: MEDIUM - Local users or processes with filesystem access can trigger system crashes, potentially disrupting services.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and ability to trigger specific filesystem operations. The kernel panic occurs during unmount.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in Linux kernel stable releases via commits referenced in CVE

Vendor Advisory: https://git.kernel.org/stable/c/005f9cdab70c915702254c5eb67a8efced80e821

Restart Required: Yes

Instructions:

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

🔧 Temporary Workarounds

Avoid F2FS filesystem

linux

Do not use F2FS filesystem until patched

Mount F2FS as read-only

linux

Mount existing F2FS filesystems as read-only to prevent trigger conditions

mount -o remount,ro /path/to/f2fs/mountpoint

🧯 If You Can't Patch

Avoid unmounting F2FS filesystems if possible
Monitor for kernel panic logs and have recovery procedures ready

🔍 How to Verify

Check if Vulnerable:

Check if F2FS filesystem is in use: 'mount | grep f2fs' and check kernel version against patched versions

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits or is newer than vulnerable versions

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages mentioning f2fs_destroy_node_manager
F2FS orphan inode warnings
Buffer I/O errors on F2FS devices

SIEM Query:

source="kernel" AND ("f2fs_destroy_node_manager" OR "F2FS-fs.*orphan inode" OR "kernel BUG.*f2fs")

📊 Metadata

CVE ID: CVE-2022-49255

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

EPSS Score: 0.04% exploit probability (12.7th percentile)

Published: February 26, 2025

Last Updated: October 21, 2025

🔗 References

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