CVE-2024-42225: Linux Kernel Data Leak Vulnerability

CVE-2024-42225 Overview

CVE-2024-42225 is an uninitialized memory use vulnerability in the Linux kernel's mt76 WiFi driver. The vulnerability exists in the MediaTek mt76 wireless driver where the skb_put function was used instead of skb_put_zero, potentially allowing uninitialized data to be reused within socket buffer operations. This memory safety issue could be exploited by an attacker on an adjacent network to potentially compromise system confidentiality, integrity, and availability.

Critical Impact

Uninitialized memory use in the mt76 WiFi driver could allow adjacent network attackers to potentially leak sensitive kernel memory contents or cause system instability through manipulation of wireless network packets.

Affected Products

• Linux Kernel (multiple versions with mt76 WiFi driver support)
• Systems using MediaTek mt76-based wireless network adapters
• Debian-based distributions (security advisory issued)

Discovery Timeline

• 2024-07-30 - CVE CVE-2024-42225 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2024-42225

Vulnerability Analysis

The vulnerability resides in the mt76 WiFi driver within the Linux kernel, specifically related to socket buffer (skb) memory handling. The driver uses skb_put to extend the data portion of a socket buffer, but this function does not zero-initialize the newly allocated memory region. When memory is not properly initialized before use, it may contain residual data from previous allocations, leading to potential information disclosure or unpredictable behavior.

The CWE-908 classification (Use of Uninitialized Resource) accurately describes this vulnerability class. In kernel space, uninitialized memory can contain sensitive information from other processes or kernel operations, making this a significant security concern for systems with wireless network exposure.

Root Cause

The root cause of CVE-2024-42225 is the improper use of skb_put in the mt76 driver codebase. The skb_put function extends the used data area of a socket buffer but does not initialize the new memory to zero. This allows potentially sensitive data that resided in that memory region from previous allocations to be inadvertently included in network packets or processed by the driver logic.

The fix involves replacing skb_put with skb_put_zero, which performs the same buffer extension operation but additionally zeros out the newly allocated memory region, ensuring that no uninitialized data can be reused.

Attack Vector

The vulnerability requires adjacent network access (AV:A), meaning an attacker must be on the same network segment as the vulnerable system, typically within WiFi range. The attack complexity is high (AC:H), indicating that successful exploitation requires specific conditions to be met. No privileges or user interaction are required for exploitation.

An attacker could potentially:

• Craft malicious WiFi frames to trigger the vulnerable code path
• Exploit the uninitialized memory to leak kernel memory contents
• Cause denial of service through memory corruption

The vulnerability is exploited through WiFi protocol interactions with systems running the vulnerable mt76 driver. Due to the nature of uninitialized memory issues, the specific exploitation technique would depend on the memory contents and timing conditions during the attack.

Detection Methods for CVE-2024-42225

Indicators of Compromise

• Unexpected kernel panics or crashes related to the mt76 wireless driver module
• Anomalous network behavior on systems with MediaTek WiFi adapters
• Kernel log messages indicating memory corruption in wireless subsystem components
• Unusual wireless frame patterns in network traffic captures

Detection Strategies

• Monitor kernel logs for mt76 driver errors or warnings using dmesg | grep mt76
• Implement wireless intrusion detection systems (WIDS) to identify anomalous WiFi traffic
• Deploy kernel auditing tools to track memory allocation patterns in network subsystems
• Use SentinelOne Singularity Platform for real-time kernel-level threat detection

Monitoring Recommendations

• Enable verbose logging for the mt76 WiFi driver during investigation periods
• Monitor system stability metrics on hosts with MediaTek wireless adapters
• Review wireless network traffic for malformed frames targeting known vulnerabilities
• Implement network segmentation to limit adjacent network attack surface

How to Mitigate CVE-2024-42225

Immediate Actions Required

• Update the Linux kernel to a patched version that includes the skb_put_zero fix
• Review systems using MediaTek mt76-based wireless adapters for vulnerability exposure
• Consider disabling WiFi functionality on critical systems until patches are applied
• Implement network isolation for systems that cannot be immediately patched

Patch Information

Linux kernel maintainers have released patches addressing this vulnerability across multiple stable kernel branches. The fix replaces skb_put with skb_put_zero in the affected mt76 driver code to ensure proper memory initialization.

Official patch commits are available from the kernel git repository:

• Kernel Git Commit 22ea2a7f
• Kernel Git Commit 64f86337
• Kernel Git Commit 7f819a2f
• Kernel Git Commit dc7f14d0
• Kernel Git Commit ff6b26be

Debian users should refer to the Debian LTS Announcement for distribution-specific guidance.

Workarounds

• Disable the mt76 WiFi driver module if wireless functionality is not required: modprobe -r mt76
• Use wired Ethernet connections instead of WiFi on affected systems
• Implement strict network access controls to limit adjacent network exposure
• Deploy wireless network monitoring to detect potential exploitation attempts

# Check if mt76 driver is loaded
lsmod | grep mt76

# Temporarily disable mt76 driver (if wireless not needed)
sudo modprobe -r mt76_usb mt76x2u mt76x0u mt76

# Blacklist mt76 driver to prevent loading at boot
echo "blacklist mt76" | sudo tee /etc/modprobe.d/blacklist-mt76.conf

# Verify kernel version for patch status
uname -r