Executive brief
A synchronization issue was identified in the Linux kernel's graphics memory management component. This flaw could lead to system instability or kernel warnings when the system attempts to reclaim memory used by graphics drivers. While primarily affecting internal testing tools, it represents a potential reliability risk for systems under heavy memory pressure.
Technical details
A locking issue exists in the Linux kernel's DRM (Direct Rendering Manager) SHMEM helper component. Specifically, the `drm_gem_shmem_purge_locked()` function was being called without holding the required GEM object reservation lock. This violation of locking primitives can lead to race conditions or kernel warnings during memory purging operations. The fix introduces a new helper, `drm_gem_shmem_purge()`, which correctly acquires and releases the `dma_resv` lock around the purge operation. This vulnerability is primarily reachable during KUnit testing but reflects an underlying architectural requirement for proper synchronization in SHMEM-backed GEM objects.
Affected products
- Linux Linux Kernel v6.16+
Timeline
- 2025-12-12: patched: Initial patch authored
- 2026-05-08: advisory: CVE published