CVE-2024-26913: Linux Kernel Buffer Overflow Vulnerability

CVE-2024-26913 Overview

CVE-2024-26913 is an Integer Underflow vulnerability in the Linux kernel's AMD Display driver, specifically affecting the DCN35 (Display Core Next 3.5) component. The vulnerability occurs due to a missing ODM (Output Data Mapping) calculation in the pipe split policy determination logic, which can cause display underflow and corruption issues when rendering at high resolutions such as 8K at 30Hz.

Critical Impact

This vulnerability allows local attackers with low privileges to potentially achieve high impact on confidentiality, integrity, and availability of the affected system through the display subsystem.

Affected Products

• Linux kernel with AMD Display DCN35 driver
• Systems with AMD graphics hardware utilizing DCN35 architecture
• Linux Linux Kernel

Discovery Timeline

• 2024-04-17 - CVE CVE-2024-26913 published to NVD
• 2025-03-07 - Last updated in NVD database

Technical Details for CVE-2024-26913

Vulnerability Analysis

The vulnerability exists within the AMD Display driver's DCN35 implementation in the Linux kernel. The root cause is a missing ODM (Output Data Mapping) calculation that is essential for proper pipe split policy determination. When this calculation is omitted, the display subsystem cannot correctly manage data flow for high-bandwidth display configurations, resulting in buffer underflow conditions.

The issue manifests primarily during high-resolution display operations, particularly when driving 8K displays at 30Hz refresh rates. The pipe splitting mechanism, which is designed to distribute display workload across multiple display pipes for bandwidth-intensive operations, fails to account for ODM requirements, leading to data corruption and visual artifacts.

Root Cause

The vulnerability stems from CWE-191 (Integer Underflow), where the absence of the ODM calculation in the pipe split policy code path causes incorrect buffer management. The display controller expects properly calculated values for distributing pixel data across display pipes, but without the ODM calculation, these values can underflow, leading to memory access violations and display corruption.

Attack Vector

This is a local attack vector requiring an authenticated user with low privileges to exploit. An attacker with local access to a system with vulnerable AMD DCN35 display hardware could potentially trigger the vulnerability by:

1. Configuring display output to high-resolution modes (8K30)
2. Triggering display pipe split operations through specific display configurations
3. Exploiting the resulting underflow condition to impact system stability or potentially corrupt memory

The vulnerability does not require user interaction and operates within an unchanged security scope, meaning the impact is contained to the vulnerable component's security authority.

The fix adds the missing ODM calculation to ensure proper pipe split policy determination. The patch introduces the necessary computational logic to correctly handle high-resolution display configurations without causing underflow conditions.

Detection Methods for CVE-2024-26913

Indicators of Compromise

• Display corruption or visual artifacts when using high-resolution output (8K30)
• System logs showing display underflow errors from the amdgpu or drm kernel modules
• Unexpected kernel warnings or errors related to DCN35 pipe split operations
• System instability when driving high-bandwidth display configurations

Detection Strategies

• Monitor kernel logs for drm/amd/display related error messages indicating underflow conditions
• Check for kernel oops or warnings in dmesg output related to the AMD display driver
• Audit installed kernel versions against fixed versions to identify vulnerable systems
• Use SentinelOne Singularity platform to detect anomalous kernel behavior patterns

Monitoring Recommendations

• Enable verbose logging for the AMD display driver module to capture underflow events
• Implement system monitoring for kernel panic events or display subsystem crashes
• Configure alerting for unusual display driver behavior in enterprise environments
• Deploy SentinelOne agents to continuously monitor kernel-level activities and detect exploitation attempts

How to Mitigate CVE-2024-26913

Immediate Actions Required

• Update the Linux kernel to a patched version that includes the ODM calculation fix
• If updating is not immediately possible, avoid using 8K30 display configurations on affected systems
• Review and apply the kernel patches from the official git commits
• Monitor systems for signs of exploitation or display-related instability

Patch Information

The Linux kernel maintainers have released patches to address this vulnerability. The fixes are available through the following kernel git commits:

• Kernel Git Commit cdbe0be8874c
• Kernel Git Commit faf51b201bc4

Organizations should update to kernel versions containing these patches through their Linux distribution's package management system.

Workarounds

• Limit display resolution to below 8K to avoid triggering the vulnerable code path
• Disable pipe splitting functionality if possible through kernel module parameters
• Use alternative display drivers or configurations that do not utilize DCN35 features
• Consider using a different graphics configuration until patches can be applied

# Check current kernel version for vulnerability assessment
uname -r

# View AMD display driver messages for underflow errors
dmesg | grep -i "amd\|drm\|display\|underflow"

# Update kernel packages (Debian/Ubuntu example)
sudo apt update && sudo apt upgrade linux-image-generic

# Update kernel packages (RHEL/CentOS example)
sudo dnf update kernel