CVE-2023-52818 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/amd: Fix UBSAN array-index-out-of-bounds for SMU7
For pptable structs that use flexible array sizes, use flexible arrays.
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Analysis
by VulDB Data Team • 03/06/2025
The vulnerability CVE-2023-52818 represents a critical array index out-of-bounds issue within the AMD display driver subsystem of the Linux kernel. This flaw specifically affects the SMU7 (System Management Unit) component responsible for power management and thermal control in AMD graphics hardware. The issue manifests in the drm/amd driver module where improper handling of flexible array sizes in power table structures creates potential for memory corruption and system instability. The vulnerability was identified through unified kernel self-protection mechanisms and addressed through a targeted fix that properly implements flexible array usage patterns.
The technical root cause of this vulnerability lies in the improper implementation of flexible array structures within the power table (pptable) handling code. When the kernel processes power management data for AMD graphics hardware, it encounters structures that should utilize flexible array members to accommodate varying data sizes. However, the original implementation failed to properly account for these flexible array boundaries, leading to scenarios where array indexing operations could exceed valid memory bounds. This type of vulnerability falls under CWE-129 which specifically addresses insufficient validation of array indices, and represents a classic case of out-of-bounds memory access that can lead to arbitrary code execution or system crashes.
The operational impact of CVE-2023-52818 extends beyond simple system instability to potentially enable privilege escalation and denial of service conditions within graphics-intensive applications. Systems running affected kernel versions experience heightened risk when processing graphics workloads that interact with AMD GPU power management features. Attackers could potentially exploit this vulnerability to execute malicious code with kernel privileges, particularly in environments where graphics processing is heavily utilized such as gaming platforms, workstation environments, or server configurations with AMD graphics hardware. The vulnerability affects all systems using AMD GPUs with SMU7 firmware components and impacts the broader drm/amd subsystem that manages display and graphics hardware communication.
Mitigation strategies for CVE-2023-52818 require immediate kernel updates to patched versions that properly implement flexible array handling in the AMD display driver code. System administrators should prioritize applying the latest security patches from their respective Linux distributions, particularly those addressing the drm/amd subsystem and SMU7 power management components. Additionally, organizations should implement monitoring for unusual system behavior or crashes during graphics-intensive operations that might indicate exploitation attempts. The fix implemented addresses the underlying issue by ensuring proper flexible array usage patterns in power table structures, aligning with industry best practices for memory safety in kernel space code. This vulnerability demonstrates the importance of proper array boundary checking in kernel drivers and aligns with ATT&CK technique T1068 which covers local privilege escalation through kernel vulnerabilities. Organizations should also consider implementing kernel module integrity checks and monitoring for unauthorized kernel modifications that could potentially bypass the patched protections.