CVE-2024-42122 in Linux
Summary
by MITRE • 07/30/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add NULL pointer check for kzalloc
[Why & How]
Check return pointer of kzalloc before using it.
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Analysis
by VulDB Data Team • 07/19/2025
The vulnerability identified as CVE-2024-42122 resides within the Linux kernel's AMD display subsystem, specifically within the direct rendering manager drm/amd/display component. This issue represents a classic null pointer dereference vulnerability that occurs when the system fails to properly validate the return value from the kzalloc memory allocation function before attempting to use the resulting pointer. The vulnerability stems from inadequate error handling in the display driver's memory management routines where the kernel does not verify whether kzalloc successfully allocated memory before proceeding with operations on the returned pointer.
The technical flaw manifests when the drm/amd/display driver invokes kzalloc to allocate memory for display-related structures or data buffers, but fails to check whether the allocation succeeded. When kzalloc returns a NULL pointer due to memory exhaustion or allocation failure, subsequent code attempts to dereference this NULL pointer, leading to a kernel panic or system crash. This pattern violates fundamental memory safety principles and represents a CWE-476 null pointer dereference vulnerability that can be exploited to cause denial of service conditions or potentially enable privilege escalation depending on the execution context. The vulnerability operates at the kernel level where such failures can have catastrophic consequences for system stability and security.
The operational impact of this vulnerability extends beyond simple system crashes as it affects the reliability of graphics rendering and display functionality on systems utilizing AMD graphics hardware. When triggered, the kernel panic caused by the null pointer dereference results in complete system shutdown, requiring manual intervention to restore normal operation. This vulnerability particularly affects systems running Linux kernel versions that include the affected drm/amd/display driver code, potentially impacting desktop environments, servers with graphics capabilities, and embedded systems that rely on AMD display drivers for proper operation. The vulnerability's exploitation requires only the normal operation of display-related functions, making it a latent risk that can be triggered by routine system operations.
Mitigation strategies for CVE-2024-42122 focus on implementing proper error handling practices within the kernel codebase. The solution requires adding explicit NULL pointer checks immediately after kzalloc calls to validate memory allocation success before proceeding with pointer usage. This approach aligns with the principle of defensive programming and follows the ATT&CK technique T1484.001 for privilege escalation through kernel exploitation. System administrators should prioritize applying kernel updates that include the patched drm/amd/display driver code, which incorporates the necessary null pointer validation checks. Additionally, monitoring systems for kernel panics or display driver failures can help identify potential exploitation attempts. The fix should be implemented following secure coding practices that emphasize early validation of system calls and resource allocations, ensuring that all memory management operations include proper error handling to prevent similar vulnerabilities in other kernel subsystems. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security fixes across their Linux-based infrastructure.