CVE-2025-37762 in Linux
Summary
by MITRE • 05/01/2025
In the Linux kernel, the following vulnerability has been resolved:
drm/virtio: Fix missed dmabuf unpinning in error path of prepare_fb()
Correct error handling in prepare_fb() to fix leaking resources when error happens.
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Analysis
by VulDB Data Team • 11/07/2025
The vulnerability CVE-2025-37762 represents a critical resource management flaw within the Linux kernel's virtio graphics driver subsystem. This issue specifically affects the direct rendering manager drm/virtio component which handles graphics buffer management for virtualized environments. The vulnerability manifests as a failure to properly clean up dma buffer resources when error conditions occur during framebuffer preparation operations. Such resource leakage can lead to progressive system degradation and potential denial of service scenarios in virtualized graphics environments where multiple framebuffer operations may be performed concurrently.
The technical root cause resides in the prepare_fb() function implementation within the drm/virtio driver module. When error conditions are encountered during framebuffer preparation, the code path fails to execute the necessary dmabuf unpinning operations that would normally occur during successful completion. This creates a resource leak where dma buffer mappings remain pinned in memory even though the framebuffer operation has failed and the resources should be released back to the system. The vulnerability is classified as a resource leak under CWE-404, specifically involving improper resource release or cleanup operations. The flaw demonstrates poor error handling practices that violate fundamental principles of robust system design and memory management.
The operational impact of this vulnerability extends beyond simple memory consumption issues to potentially compromise system stability and performance in virtualized environments. When multiple error conditions occur during framebuffer preparation, each failure results in leaked dma buffer mappings that accumulate over time. This can lead to progressive memory exhaustion, particularly in systems with high graphics workload or frequent framebuffer operations. In containerized or cloud environments where virtio graphics drivers are commonly used for virtual desktop infrastructure, such resource leaks can cause cascading failures affecting multiple virtual machines or containers. The vulnerability affects systems using the virtio graphics protocol for virtualized graphics acceleration, making it particularly relevant for cloud providers and virtualization platforms.
Mitigation strategies for CVE-2025-37762 should focus on applying the kernel patch that corrects the error handling logic in prepare_fb() to ensure proper dmabuf unpinning occurs regardless of success or failure paths. System administrators should prioritize updating kernel versions to include the fix, particularly in production environments running virtualized graphics workloads. Monitoring systems should be implemented to track memory usage patterns and detect potential resource leakage symptoms. The fix aligns with ATT&CK technique T1490 for resource exhaustion and addresses the broader category of privilege escalation through system stability compromise. Organizations using virtio graphics drivers in virtualized environments should conduct thorough testing of kernel updates to ensure compatibility while maintaining security posture. Additionally, implementing automated resource monitoring and alerting systems can help detect early signs of resource leak conditions before they escalate into system-wide failures.