CVE-2023-52921 in Linux
Summary
by MITRE • 11/19/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix possible UAF in amdgpu_cs_pass1()
Since the gang_size check is outside of chunk parsing loop, we need to reset i before we free the chunk data.
Suggested by Ye Zhang (@VAR10CK) of Baidu Security.
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Analysis
by VulDB Data Team • 10/22/2025
The vulnerability identified as CVE-2023-52921 affects the Linux kernel's amdgpu driver component, specifically within the drm/amdgpu subsystem responsible for managing graphics processing units. This issue manifests as a potential use-after-free condition that could compromise system stability and security integrity. The flaw exists in the amdgpu_cs_pass1() function which handles command submission processing for AMD graphics hardware, making it particularly concerning for systems utilizing AMD GPUs in enterprise or high-security environments.
The technical root cause of this vulnerability stems from improper loop control logic within the command submission processing code. During chunk parsing operations, the gang_size validation check occurs outside of the processing loop structure, creating a scenario where loop variables are not properly reset before memory deallocation occurs. This misalignment between validation timing and memory management creates a window where freed memory locations may still be referenced, leading to unpredictable behavior when the system attempts to access already released resources. The vulnerability specifically impacts the driver's handling of command submission chunks, where memory allocated for processing is freed without proper reinitialization of loop counters, resulting in potential memory corruption scenarios.
The operational impact of this vulnerability extends beyond simple system instability to potentially enable privilege escalation or denial-of-service conditions within graphics-intensive applications. Attackers could exploit this condition to cause kernel crashes, system hangs, or potentially execute arbitrary code with kernel-level privileges when submitting specially crafted graphics commands. The vulnerability affects systems running affected Linux kernel versions where AMD GPU drivers are active, particularly impacting servers, workstations, and embedded systems that rely on graphics processing capabilities. This represents a significant concern for organizations using Linux-based systems in security-sensitive environments where system reliability and integrity are paramount.
Mitigation strategies for CVE-2023-52921 should focus on immediate kernel updates that contain the patched amdgpu driver code, ensuring proper loop variable reset before memory deallocation occurs. System administrators should prioritize patching affected systems and monitoring for any unusual behavior following updates. Additional protective measures include implementing kernel lockdown mechanisms, restricting graphics driver access where possible, and maintaining comprehensive system monitoring to detect potential exploitation attempts. The vulnerability aligns with CWE-416, which addresses use-after-free conditions, and could potentially map to ATT&CK techniques involving privilege escalation or denial-of-service attacks through kernel exploitation. Organizations should also consider implementing automated patch management processes to ensure timely remediation of similar vulnerabilities in the graphics driver stack.