CVE-2024-26948 in Linux
Summary
by MITRE • 05/01/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add a dc_state NULL check in dc_state_release
[How]
Check wheather state is NULL before releasing it.
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Analysis
by VulDB Data Team • 01/26/2026
The vulnerability CVE-2024-26948 represents a critical null pointer dereference issue within the AMD display driver subsystem of the Linux kernel. This flaw exists in the drm/amd/display component where the dc_state_release function fails to validate whether the dc_state parameter is NULL before attempting to release it. The vulnerability stems from inadequate input validation in the display controller state management code that handles display configuration states for AMD graphics hardware. When a display state object is improperly handled or becomes invalid during the release process, the kernel attempts to dereference a NULL pointer, leading to potential system crashes or unexpected behavior. This type of vulnerability falls under CWE-476 which specifically addresses NULL pointer dereference conditions that can result in denial of service or system instability. The issue occurs within the graphics subsystem's memory management routines where display configuration states are maintained and released during display mode changes or system operations.
The operational impact of this vulnerability extends beyond simple system instability to potentially enable denial of service attacks against systems running affected Linux kernels. When the null pointer dereference occurs during display state release operations, it can cause the kernel to crash or become unresponsive, effectively rendering the graphics subsystem inoperative. This affects systems that rely on AMD graphics hardware for display output, including desktop computers, servers, and embedded systems with GPU acceleration. The vulnerability is particularly concerning because display drivers operate in kernel space where such faults can lead to complete system hangs or require manual rebooting to recover. Attackers could potentially exploit this by triggering specific display configuration scenarios that cause the kernel to attempt releasing invalid display state objects. This aligns with ATT&CK technique T1068 which involves exploiting local privileges to cause system instability through kernel vulnerabilities.
Mitigation strategies for CVE-2024-26948 focus on implementing proper null pointer validation within the display driver code as specified in the patch. The fix requires adding a conditional check to verify that the dc_state parameter is not NULL before proceeding with the release operation. This defensive programming approach prevents the kernel from attempting to dereference invalid memory addresses during display state management. System administrators should prioritize updating to kernel versions that contain the patched code, typically those released after the vulnerability disclosure. Organizations running affected systems should implement monitoring for display driver related kernel panics or system crashes that might indicate exploitation attempts. The patch implementation follows standard security practices for preventing null pointer dereferences and represents a minimal but critical fix that addresses the root cause without altering the broader display subsystem functionality. Regular kernel updates and security patch management processes become essential for maintaining system stability and preventing exploitation of similar vulnerabilities in the graphics driver stack.