CVE-2022-48905 – This CVE describes a memory leak vulnerability ... (How to Fix)

Q: What is the severity of CVE-2022-48905?

CVE-2022-48905 has a CVSS score of 5.5 (MEDIUM). This CVE describes a memory leak vulnerability in the Linux kernel's ibmvnic driver. When flushing the reset work queue, the driver fails to properly free reset work items, leading to gradual memory consumption. This affects Linux systems using the ibmvnic driver, typically on IBM Power Systems with virtual network interfaces.

📋 TL;DR

This CVE describes a memory leak vulnerability in the Linux kernel's ibmvnic driver. When flushing the reset work queue, the driver fails to properly free reset work items, leading to gradual memory consumption. This affects Linux systems using the ibmvnic driver, typically on IBM Power Systems with virtual network interfaces.

💻 Affected Systems

Products:

Linux kernel

Versions: Kernel versions with ibmvnic driver before the fix commits

Operating Systems: Linux distributions running on IBM Power Systems

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems using the ibmvnic driver, typically IBM Power Systems with virtualized network interfaces. Not applicable to x86 systems or systems without ibmvnic.

📦 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 →

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

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

🟠

Likely Case

Gradual memory consumption over time leading to performance degradation and eventual system instability requiring reboot.

🟢

If Mitigated

Minimal impact with proper memory monitoring and regular patching; memory leak would be detected before causing system failure.

🌐 Internet-Facing: LOW - Requires local access or ability to trigger ibmvnic reset operations; not directly exploitable over network.

🏢 Internal Only: MEDIUM - Internal users or processes with ability to trigger network interface resets could gradually degrade system performance.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires ability to trigger ibmvnic reset operations, typically requiring local access or specific driver operations. No known public exploits.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing commits: 39738a2346b270e8f72f88d8856de2c167bd2899, 4c26745e4576cec224092e6cc12e37829333b183, 58b07100c20e95c78b8cb4d6d28ca53eb9ef81f2, 6acbc8875282d3ca8a73fa93cd7a9b166de5019c, 786576c03b313a9ff6585458aa0dfd039d897f51

Vendor Advisory: https://git.kernel.org/stable/c/39738a2346b270e8f72f88d8856de2c167bd2899

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (yum update kernel, apt-get upgrade linux-image). 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable ibmvnic driver

linux

Remove or blacklist ibmvnic driver if not required

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

Monitor memory usage

linux

Implement monitoring for abnormal memory consumption

watch -n 60 'cat /proc/meminfo | grep -E "MemFree|MemAvailable"'

🧯 If You Can't Patch

Implement strict memory monitoring with alerts for abnormal consumption
Limit user access to network interface configuration and reset operations

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if ibmvnic module is loaded: uname -r && lsmod | grep ibmvnic

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits and ibmvnic module loads without errors: dmesg | grep -i ibmvnic

📡 Detection & Monitoring

Log Indicators:

Kernel oom-killer messages
Increasing memory usage in /var/log/messages
ibmvnic driver error messages

Network Indicators:

Network interface resets without clear cause

SIEM Query:

source="kernel" AND ("oom" OR "out of memory" OR "ibmvnic")

📊 Metadata

CVE ID: CVE-2022-48905

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

Published: August 22, 2024

Last Updated: September 12, 2024

🔗 References

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