CVE-2025-71076 Overview
A vulnerability has been identified in the Linux kernel's DRM (Direct Rendering Manager) XE graphics driver within the OA (Observation Architecture) subsystem. The vulnerability exists due to missing input validation on the num_syncs parameter during OA open operations. This flaw allows userspace applications to pass arbitrarily large values for num_syncs, potentially leading to excessive memory allocations and system resource exhaustion.
Critical Impact
Userspace applications can exploit this vulnerability to cause denial of service conditions through memory exhaustion by supplying oversized allocation requests to the kernel's DRM/XE OA subsystem.
Affected Products
- Linux kernel with DRM/XE graphics driver
- Systems utilizing Intel Xe graphics architecture
- Linux distributions running affected kernel versions
Discovery Timeline
- January 13, 2026 - CVE-2025-71076 published to NVD
- January 13, 2026 - Last updated in NVD database
Technical Details for CVE-2025-71076
Vulnerability Analysis
The vulnerability resides in the Linux kernel's DRM/XE OA (Observation Architecture) subsystem, which is part of the Intel Xe graphics driver infrastructure. The OA component provides performance monitoring and observation capabilities for graphics workloads. During the processing of OA open requests, the kernel accepts a num_syncs parameter from userspace that specifies the number of synchronization objects to be allocated.
The root issue stems from the kernel's failure to validate the bounds of this user-supplied parameter before using it in memory allocation operations. An attacker with local access could craft malicious ioctl requests containing extremely large num_syncs values, forcing the kernel to attempt memory allocations far exceeding reasonable operational limits.
Root Cause
The vulnerability originates from insufficient input validation in the DRM/XE OA open parameter handling code. The num_syncs parameter was accepted from userspace without any upper bound checking, violating the principle of never trusting user-supplied input in kernel code paths. This oversight allows the parameter to be used directly in memory allocation calculations, creating an opportunity for resource exhaustion attacks.
Attack Vector
Exploitation requires local access to the system with permissions to interact with the DRM subsystem through ioctl calls. An attacker would craft a malicious request to the OA open interface with an excessively large num_syncs value. When processed by the kernel, this triggers oversized memory allocation attempts that can lead to system instability, out-of-memory conditions, or denial of service.
The attack is performed through the DRM ioctl interface, targeting the XE OA open operation. By manipulating the num_syncs parameter to contain values far exceeding the expected operational range, an attacker can force the kernel into allocating large amounts of memory, potentially exhausting system resources.
Detection Methods for CVE-2025-71076
Indicators of Compromise
- Unusual memory consumption spikes associated with DRM/XE driver operations
- System logs showing excessive memory allocation attempts from the xe kernel module
- Kernel warnings or out-of-memory (OOM) killer activations following DRM ioctl operations
- Abnormal process activity targeting /dev/dri/ device nodes with high-frequency ioctl calls
Detection Strategies
- Monitor kernel logs (dmesg) for DRM/XE OA-related error messages or allocation failures
- Implement audit rules to track ioctl calls to DRM device nodes (/dev/dri/card*, /dev/dri/renderD*)
- Use kernel tracing tools (ftrace, eBPF) to monitor drm_xe module function calls for anomalous behavior
- Deploy endpoint detection solutions capable of monitoring kernel-level resource allocation patterns
Monitoring Recommendations
- Configure memory usage alerts for processes interacting with graphics subsystems
- Enable kernel auditing for DRM subsystem interactions using auditd
- Implement resource limits (cgroups) for processes that legitimately interact with DRM devices
- Monitor for sudden memory pressure events correlated with graphics driver activity
How to Mitigate CVE-2025-71076
Immediate Actions Required
- Update the Linux kernel to a version containing the security fix
- Review and restrict access to DRM device nodes where possible
- Apply kernel patches from the official Linux kernel git repositories
- Consider temporarily disabling XE OA functionality if not required for operations
Patch Information
The vulnerability has been resolved by adding a validation check to ensure that num_syncs does not exceed DRM_XE_MAX_SYNCS. When this limit is violated, the kernel now returns -EINVAL (invalid argument) instead of attempting the allocation. The fix also utilizes XE_IOCTL_DBG() for improved debugging capabilities.
The patches are available through the following official kernel commits:
Workarounds
- Restrict access to DRM device nodes (/dev/dri/*) using file permissions or ACLs to limit exposure
- Implement cgroups memory limits for processes that require DRM access to contain potential resource exhaustion
- Use SELinux or AppArmor policies to restrict which processes can interact with the XE graphics driver
- Monitor and alert on unusual memory allocation patterns from the DRM subsystem as a detective control
# Restrict DRM device access to specific group
chmod 660 /dev/dri/card*
chmod 660 /dev/dri/renderD*
chown root:video /dev/dri/card*
chown root:video /dev/dri/renderD*
# Add only trusted users to the video group
# usermod -aG video trusted_user
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
