CVE-2022-49168 – This CVE-2022-49168 is a use-after-free vulnera... (How to Fix)

Q: What is the severity of CVE-2022-49168?

CVE-2022-49168 has a CVSS score of 7.8 (HIGH). This CVE-2022-49168 is a use-after-free vulnerability in the Linux kernel's Btrfs filesystem driver. When a repair bio submission fails, improper cleanup can lead to race conditions causing kernel crashes or potential privilege escalation. This affects Linux systems using Btrfs filesystem with unpatched kernels.

📋 TL;DR

This CVE-2022-49168 is a use-after-free vulnerability in the Linux kernel's Btrfs filesystem driver. When a repair bio submission fails, improper cleanup can lead to race conditions causing kernel crashes or potential privilege escalation. This affects Linux systems using Btrfs filesystem with unpatched kernels.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific kernel versions with the vulnerable Btrfs code (check git commits for exact ranges)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems using Btrfs filesystem. Systems using ext4, xfs, or other filesystems are not vulnerable.

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash, or potential privilege escalation to root if an attacker can trigger the race condition and execute arbitrary code.

🟠

Likely Case

System instability, kernel crashes, or denial of service when Btrfs repair operations encounter specific error conditions.

🟢

If Mitigated

Minimal impact if systems are not using Btrfs filesystem or have proper kernel hardening protections.

🌐 Internet-Facing: LOW - Requires local access or ability to trigger specific Btrfs operations.

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

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires triggering specific Btrfs repair operations and race conditions. No public exploits known as of knowledge cutoff.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing the fix commits referenced in the CVE

Vendor Advisory: https://git.kernel.org/stable/c/7170875083254b51fcc5d67f96640977083f481e

Restart Required: Yes

Instructions:

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

🔧 Temporary Workarounds

Disable Btrfs filesystem

all

Avoid using Btrfs filesystem on affected systems

Kernel module blacklist

Linux

Prevent Btrfs module from loading

echo 'blacklist btrfs' >> /etc/modprobe.d/blacklist-btrfs.conf
update-initramfs -u

🧯 If You Can't Patch

Avoid using Btrfs filesystem on critical systems
Implement strict access controls to limit who can trigger filesystem repair operations

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if Btrfs is in use: 'uname -r' and 'lsmod | grep btrfs'

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated and check if Btrfs module loads without issues

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
Btrfs error logs in dmesg
System crashes related to Btrfs operations

Network Indicators:

None - this is a local filesystem vulnerability

SIEM Query:

Search for: 'kernel panic', 'btrfs error', 'use-after-free' in system logs

📊 Metadata

CVE ID: CVE-2022-49168

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-416

EPSS Score: 0.02% exploit probability (5.3th percentile)

Published: February 26, 2025

Last Updated: January 21, 2026

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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