CVE-2022-49592

Q: What is the severity of CVE-2022-49592?

CVE-2022-49592 has a CVSS score of 7.8 (HIGH). This CVE describes an integer overflow vulnerability in the Linux kernel's STMicroelectronics STMMAC Ethernet driver. When queue numbers exceed 4, a 32-bit left shift operation overflows, causing incorrect DMA queue mapping calculations. This affects Linux systems using STMMAC Ethernet controllers with more than 4 queues configured.

7.8 HIGH

📋 TL;DR

This CVE describes an integer overflow vulnerability in the Linux kernel's STMicroelectronics STMMAC Ethernet driver. When queue numbers exceed 4, a 32-bit left shift operation overflows, causing incorrect DMA queue mapping calculations. This affects Linux systems using STMMAC Ethernet controllers with more than 4 queues configured.

💻 Affected Systems

Products:

Linux kernel with STMMAC Ethernet driver

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

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable when using STMMAC Ethernet controllers with more than 4 queues configured. Systems with CONFIG_UBSAN enabled will show warnings but may not crash.

📦 What is this software?

Linux Kernel by Linux

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⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic or system crash due to memory corruption, potentially leading to denial of service and system instability.

🟠

Likely Case

System instability, network interface failures, or kernel warnings/panics when configuring network interfaces with multiple queues.

🟢

If Mitigated

Minor performance impact or warnings if UBSAN is enabled, but system remains functional.

🌐 Internet-Facing: LOW - Requires local access to trigger via network configuration changes.

🏢 Internal Only: MEDIUM - Local users or processes with network configuration privileges could trigger the issue, causing system instability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires local access and ability to configure network interfaces with multiple queues. The vulnerability is triggered during network interface setup.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 508d86ead36c, 573768dede0e, 613b065ca32e, 7c687a893f5c, a3ac79f38d35

Vendor Advisory: https://bugzilla.kernel.org/show_bug.cgi?id=216195

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager to update kernel package. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Limit queue configuration

Linux

Configure STMMAC interfaces to use 4 or fewer queues to avoid triggering the overflow

ethtool -L <interface> rx 4 tx 4

Disable UBSAN

Linux

Disable Undefined Behavior Sanitizer to prevent kernel warnings (does not fix vulnerability)

Rebuild kernel without CONFIG_UBSAN

🧯 If You Can't Patch

Avoid configuring STMMAC interfaces with more than 4 queues
Restrict network configuration privileges to trusted users only

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if using STMMAC driver with >4 queues. Look for UBSAN warnings in dmesg about shift-out-of-bounds in dwmac4_core.c

Check Version:

uname -r

Verify Fix Applied:

Check that kernel version includes fix commits. Verify no UBSAN warnings appear when configuring network interfaces with multiple queues.

📡 Detection & Monitoring

Log Indicators:

UBSAN: shift-out-of-bounds warnings in kernel logs
Kernel panic or oops messages related to stmmac/dwmac4

Network Indicators:

Network interface failures during configuration
Unexpected network service disruptions

SIEM Query:

source="kernel" AND ("shift-out-of-bounds" OR "dwmac4_core.c" OR "stmmac")

📊 Metadata

CVE ID: CVE-2022-49592

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

EPSS Score: 0.04% exploit probability (10.3th percentile)

Published: February 26, 2025

Last Updated: October 22, 2025

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Limit queue configuration

Disable UBSAN

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

Network Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export

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