CVE-2022-48712 – A memory corruption vulnerability in the Linux ... (How to Fix)

Q: What is the severity of CVE-2022-48712?

CVE-2022-48712 has a CVSS score of 7.8 (HIGH). A memory corruption vulnerability in the Linux kernel's ext4 filesystem fast commit feature. When krealloc() fails in ext4_fc_record_modified_inode(), improper error handling could lead to memory corruption or kernel crashes. This affects Linux systems using ext4 filesystem with fast commit enabled.

📋 TL;DR

A memory corruption vulnerability in the Linux kernel's ext4 filesystem fast commit feature. When krealloc() fails in ext4_fc_record_modified_inode(), improper error handling could lead to memory corruption or kernel crashes. This affects Linux systems using ext4 filesystem with fast commit enabled.

💻 Affected Systems

Products:

Linux kernel

Versions: Linux kernel versions with ext4 fast commit feature (specific affected versions not explicitly stated in CVE, but patches exist for stable branches)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable when ext4 filesystem is mounted with fast_commit feature enabled (not default on most distributions).

📦 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

Kernel panic leading to system crash, potential privilege escalation if combined with other vulnerabilities, or data corruption in ext4 filesystem.

🟠

Likely Case

System instability, kernel crashes, or denial of service affecting system availability.

🟢

If Mitigated

Limited impact if fast commit is disabled or system is patched; isolated to filesystem operations.

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

🏢 Internal Only: MEDIUM - Local users or processes could trigger the vulnerability, potentially causing system instability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: HIGH

Requires ability to trigger specific filesystem operations; no known public exploits as of CVE publication.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patched in Linux kernel stable releases (commits: 14aa3f49c7fc6424763f4323bfbc3a807b0727dc, 1b6762ecdf3cf12113772427c904aa3c420a1802, 62e46e0ffc02daa8fcfc02f7a932cc8a19601b19, cdce59a1549190b66f8e3fe465c2b2f714b98a94)

Vendor Advisory: https://git.kernel.org/stable/c/14aa3f49c7fc6424763f4323bfbc3a807b0727dc

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 matches patched release.

🔧 Temporary Workarounds

Disable ext4 fast commit feature

linux

Mount ext4 filesystems without fast_commit option to avoid triggering vulnerable code path

mount -o remount,no_fc /mount/point
Add 'no_fc' to /etc/fstab mount options

🧯 If You Can't Patch

Disable ext4 fast commit on all filesystems using mount options
Restrict local user access to minimize potential trigger scenarios

🔍 How to Verify

Check if Vulnerable:

Check if ext4 filesystem is mounted with fast_commit: mount | grep ext4 | grep fc

Check Version:

uname -r

Verify Fix Applied:

Check kernel version against patched releases and verify ext4 mount options don't include fast_commit

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/messages or dmesg
Ext4 filesystem error messages
System crash/reboot logs

Network Indicators:

None - local vulnerability only

SIEM Query:

Search for kernel panic events or ext4 filesystem errors in system logs

📊 Metadata

CVE ID: CVE-2022-48712

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-787

Published: June 20, 2024

Last Updated: September 17, 2025

🔗 References

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🔗 Related Vulnerabilities

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