CVE-2025-52532: MxGPU-Virtualization Buffer Overflow

CVE-2025-52532 Overview

CVE-2025-52532 is a race condition vulnerability in the AMD MxGPU-Virtualization driver. The flaw exists in the driver's ioctl path, where concurrent unsynchronized access to the global variable amdgv_cmd occurs in an unlocked ioctl handler. An attacker with local access can exploit this race to trigger a heap-based buffer overflow. Successful exploitation results in denial-of-service within the vulnerable system context. The vulnerability is categorized under [CWE-367] Time-of-Check Time-of-Use (TOCTOU) race condition. AMD has published details in AMD Security Bulletin #6027.

Critical Impact
Local attackers with low privileges can trigger a heap-based buffer overflow through a race condition in the MxGPU ioctl handler, leading to denial-of-service.

Affected Products

AMD MxGPU-Virtualization driver (refer to AMD Security Bulletin #6027 for affected versions)
Systems deploying AMD GPU virtualization in hypervisor environments
Workloads relying on the affected amdgv_cmd ioctl interface

Discovery Timeline

2026-05-15 - CVE-2025-52532 published to NVD
2026-05-15 - Last updated in NVD database

Technical Details for CVE-2025-52532

Vulnerability Analysis

The vulnerability resides in the ioctl handler of the AMD MxGPU-Virtualization driver. The handler operates without proper locking around the global variable amdgv_cmd. When multiple threads invoke ioctl operations concurrently, they race to read and modify shared state. This unsynchronized access creates a window where one thread modifies command parameters while another consumes them. The resulting inconsistency leads to a heap-based buffer overflow during command processing. The flaw maps to [CWE-367] Time-of-Check Time-of-Use, where validation and use of data occur non-atomically.

Root Cause

The root cause is missing synchronization primitives in the ioctl handler. The global amdgv_cmd structure is accessed without mutex or spinlock protection. Concurrent ioctl callers can observe partially updated state, leading to size or pointer fields that no longer match the allocated buffer. Subsequent memory operations using these corrupted parameters overflow the heap allocation.

Attack Vector

Exploitation requires local access with low privileges to the system exposing the MxGPU driver. The attacker spawns multiple threads issuing concurrent ioctl calls against the driver interface. Precise timing is needed to hit the race window, which raises attack complexity. The vulnerability does not require user interaction. Impact is limited to availability, with no direct confidentiality or integrity compromise.

No public proof-of-concept code has been released. Refer to AMD Security Bulletin #6027 for vendor-supplied technical context.

Detection Methods for CVE-2025-52532

Indicators of Compromise

Unexpected crashes or kernel panics involving the AMD MxGPU-Virtualization driver module
Heap corruption signatures in kernel logs referencing amdgv_cmd or related driver symbols
Repeated ioctl invocations from non-administrative local processes targeting the MxGPU device node

Detection Strategies

Monitor kernel ring buffer and dmesg output for driver fault traces, allocator warnings, or KASAN reports tied to the MxGPU driver
Audit process behavior for unprivileged users issuing high-frequency, multi-threaded ioctl calls to GPU virtualization device files
Correlate driver crash events with preceding local process activity to identify exploitation attempts

Monitoring Recommendations

Enable kernel crash dump collection on hosts running AMD MxGPU virtualization to capture forensic evidence
Centralize host telemetry and kernel logs in a SIEM for correlation across virtualization hosts
Alert on repeated driver fault events from the same host or user session

How to Mitigate CVE-2025-52532

Immediate Actions Required

Review AMD Security Bulletin #6027 and identify affected driver versions in your fleet
Apply AMD-provided patches to the MxGPU-Virtualization driver as soon as they are available for your platform
Restrict local access to systems running the affected driver, particularly multi-tenant virtualization hosts

Patch Information

AMD has published advisory information in AMD Security Bulletin #6027. Administrators should consult the bulletin for fixed driver versions and platform-specific update guidance.

Workarounds

Limit access to the MxGPU driver device nodes to trusted administrative accounts only
Reduce the number of low-privileged local users on virtualization hosts until patches are deployed
Disable or unload the MxGPU-Virtualization driver on systems that do not require GPU virtualization functionality

bash

# Configuration example: restrict access to GPU virtualization device nodes
# Verify current permissions on the MxGPU device interface
ls -l /dev/amdgv*

# Restrict access to root only until patches are applied
chmod 600 /dev/amdgv*
chown root:root /dev/amdgv*