CVE-2022-49554 – This CVE describes a race condition vulnerabili... (How to Fix)

Q: What is the severity of CVE-2022-49554?

CVE-2022-49554 has a CVSS score of 4.7 (MEDIUM). This CVE describes a race condition vulnerability in the Linux kernel's zsmalloc memory allocator. It allows concurrent page migration to interfere with asynchronous zspage freeing, potentially leading to memory corruption or kernel crashes. Systems running affected Linux kernel versions with zsmalloc enabled are vulnerable.

📋 TL;DR

This CVE describes a race condition vulnerability in the Linux kernel's zsmalloc memory allocator. It allows concurrent page migration to interfere with asynchronous zspage freeing, potentially leading to memory corruption or kernel crashes. Systems running affected Linux kernel versions with zsmalloc enabled are vulnerable.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE description, but patches are available in stable kernel trees.

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires zsmalloc to be enabled/used. Many distributions enable zsmalloc by default for zram/zswap functionality.

📦 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 →

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, denial of service, or potential privilege escalation if memory corruption can be controlled.

🟠

Likely Case

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

🟢

If Mitigated

Minimal impact if systems are patched or zsmalloc is disabled.

🌐 Internet-Facing: LOW - This requires local access or ability to trigger specific kernel operations.

🏢 Internal Only: MEDIUM - Local users or processes could potentially trigger the race condition to cause system instability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: HIGH

Exploitation requires triggering specific race conditions in kernel memory management, which is complex and timing-dependent.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patches available in stable kernel trees (commits referenced in CVE)

Vendor Advisory: https://git.kernel.org/stable/c/2505a981114dcb715f8977b8433f7540854851d8

Restart Required: Yes

Instructions:

1. Update to a patched kernel version from your distribution vendor. 2. Reboot the system to load the new kernel.

🔧 Temporary Workarounds

Disable zsmalloc

linux

Disable zsmalloc memory allocator if not required

echo 'blacklist zsmalloc' > /etc/modprobe.d/disable-zsmalloc.conf
update-initramfs -u
reboot

🧯 If You Can't Patch

Monitor system logs for kernel panics or oops messages
Restrict local user access to minimize potential trigger sources

🔍 How to Verify

Check if Vulnerable:

Check kernel version and verify if zsmalloc is enabled: 'cat /proc/config.gz | gunzip | grep CONFIG_ZSMALLOC' or check running kernel modules

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated to include the fix commits, or check that zsmalloc is disabled

📡 Detection & Monitoring

Log Indicators:

Kernel oops messages
System crashes/panics
Memory allocation errors in kernel logs

Network Indicators:

None - this is a local kernel vulnerability

SIEM Query:

source="kernel" AND ("Oops" OR "panic" OR "BUG")

📊 Metadata

CVE ID: CVE-2022-49554

CVSS v3 Score: 4.7 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-362

EPSS Score: 0.03% exploit probability (7.2th percentile)

Published: February 26, 2025

Last Updated: October 22, 2025

🔗 References

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🔗 Related Vulnerabilities

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