CVE-2022-48858 – A race condition vulnerability in the Linux ker... (How to Fix)

Q: What is the severity of CVE-2022-48858?

CVE-2022-48858 has a CVSS score of 7.0 (HIGH). A race condition vulnerability in the Linux kernel's mlx5 network driver allows use-after-free scenarios during command flush operations. This can lead to kernel crashes or potential privilege escalation. Systems using Mellanox network adapters with affected kernel versions are vulnerable.

📋 TL;DR

A race condition vulnerability in the Linux kernel's mlx5 network driver allows use-after-free scenarios during command flush operations. This can lead to kernel crashes or potential privilege escalation. Systems using Mellanox network adapters with affected kernel versions are vulnerable.

💻 Affected Systems

Products:

Linux kernel mlx5 driver for Mellanox network adapters

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

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems with Mellanox network hardware using the mlx5 driver. Virtual environments using virtual Mellanox adapters may also be affected.

📦 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 kernel mode allowing full system compromise.

🟠

Likely Case

System instability, kernel crashes, or denial of service affecting network connectivity.

🟢

If Mitigated

Minor performance impact during command processing with proper locking in place.

🌐 Internet-Facing: LOW - Requires local access to trigger the race condition.

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

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: HIGH - Requires precise timing to trigger race condition

Exploitation requires local access and ability to trigger command flush operations with specific timing.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Linux kernel with commits 0401bfb27a91d7bdd74b1635c1aae57cbb128da6 or later

Vendor Advisory: https://git.kernel.org/stable/c/0401bfb27a91d7bdd74b1635c1aae57cbb128da6

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commit. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable mlx5 driver

linux

Remove or blacklist mlx5 kernel module to prevent vulnerability

echo 'blacklist mlx5_core' > /etc/modprobe.d/blacklist-mlx5.conf
rmmod mlx5_core

🧯 If You Can't Patch

Restrict local user access to systems with Mellanox hardware
Implement strict process isolation and resource limits

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if mlx5_core module is loaded: lsmod | grep mlx5_core

Check Version:

uname -r

Verify Fix Applied:

Check kernel version contains fix commit: uname -r and verify with distribution patch notes

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
refcount_t warnings in dmesg
mlx5_core error messages

Network Indicators:

Sudden loss of network connectivity on Mellanox interfaces

SIEM Query:

source="kernel" AND "refcount_t: addition on 0; use-after-free" OR "mlx5_cmd_trigger_completions"

📊 Metadata

CVE ID: CVE-2022-48858

CVSS v3 Score: 7.0 (HIGH)

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

CWE: CWE-362

Published: July 16, 2024

Last Updated: November 21, 2024

🔗 References

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🔗 Related Vulnerabilities

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