CVE-2022-49741 – This is a memory leak vulnerability in the Linu... (How to Fix)

Q: What is the severity of CVE-2022-49741?

CVE-2022-49741 has a CVSS score of 5.5 (MEDIUM). This is a memory leak vulnerability in the Linux kernel's smscufx framebuffer driver. When the ufx_usb_probe function fails during USB device initialization, it doesn't properly clean up allocated resources, leading to kernel memory exhaustion over time. Systems using the affected driver are vulnerable.

📋 TL;DR

This is a memory leak vulnerability in the Linux kernel's smscufx framebuffer driver. When the ufx_usb_probe function fails during USB device initialization, it doesn't properly clean up allocated resources, leading to kernel memory exhaustion over time. Systems using the affected driver are vulnerable.

💻 Affected Systems

Products:

Linux kernel with smscufx driver

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

Operating Systems: Linux

Default Config Vulnerable: ⚠️ Yes

Notes: Only vulnerable when smscufx driver is loaded (typically when SMSC USB framebuffer hardware is connected)

📦 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

Sustained exploitation could lead to kernel memory exhaustion, causing system instability, denial of service, or kernel panic.

🟠

Likely Case

Memory leak gradually consumes kernel memory, potentially leading to system slowdowns or crashes when memory is exhausted.

🟢

If Mitigated

With proper monitoring and memory limits, impact is limited to potential service disruption rather than privilege escalation.

🌐 Internet-Facing: LOW - Requires physical USB device connection or USB over IP with specific hardware.

🏢 Internal Only: MEDIUM - Affects systems with SMSC USB framebuffer devices, primarily embedded or specialized systems.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires ability to trigger USB probe failures on vulnerable hardware, typically through USB device fuzzing or malformed devices.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 1b4c08844628dfc8d72d3f51b657f2a5e63b7b4b, 3931014367ef31d26af65386a4ca496f50f0cfdf, 3b3d3127f5b4291ae4caaf50f7b66089ad600480, 64fa364ad3245508d393e16ed4886f92d7eb423c, b76449ee75e21acfe9fa4c653d8598f191ed7d68

Vendor Advisory: https://git.kernel.org/stable/c/1b4c08844628dfc8d72d3f51b657f2a5e63b7b4b

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix. 2. Check your distribution's security advisories for backported patches. 3. Reboot system to load patched kernel.

🔧 Temporary Workarounds

Disable smscufx module

linux

Prevent loading of vulnerable driver if not needed

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

🧯 If You Can't Patch

Monitor kernel memory usage for unusual increases
Restrict physical USB access to prevent connection of potentially malicious devices

🔍 How to Verify

Check if Vulnerable:

Check if smscufx module is loaded: lsmod | grep smscufx

Check Version:

uname -r

Verify Fix Applied:

Check kernel version includes fix commits or verify with distribution's security advisory

📡 Detection & Monitoring

Log Indicators:

Kernel oom-killer messages
Memory allocation failures in dmesg
USB probe error messages

SIEM Query:

source="kernel" AND ("smscufx" OR "memory leak" OR "oom-killer")

📊 Metadata

CVE ID: CVE-2022-49741

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: 0.04% exploit probability (10.7th percentile)

Published: March 27, 2025

Last Updated: October 1, 2025

🔗 References

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