DMA Buffer Vulnerability in Linux Kernel's Udmabuf Component by Linux Foundation

CVE-2026-64590

What is CVE-2026-64590?

A vulnerability in the Linux kernel affecting the dma-buf subsystem occurs when the udmabuf is imported into a DRM driver, such as amdgpu, leading to spurious warnings about overlapping mappings. This issue emerges when CONFIG_DMA_API_DEBUG_SG is enabled, triggering a warning about cacheline tracking. The problem highlights redundant CPU sync operations that can be suppressed by utilizing the DMA_ATTR_SKIP_CPU_SYNC flag in dma_map_sgtable and dma_unmap_sgtable functions. By passing this flag, the need for unnecessary cacheline checks is eliminated, ensuring smoother operation and reducing debug noise for developers.

References