Vulnerability in Linux Kernel Affecting Raspberry Pi 4

CVE-2026-64149

What is CVE-2026-64149?

A vulnerability has been identified in the Linux kernel relating to the dma_map_resource() function, which improperly uses pfn_valid() to validate memory ranges. This issue is particularly significant on ARM64 platforms with SPARSEMEM configuration, leading to potential warnings and mapping errors. Specifically, during the SPI BCM2835 probe on the Raspberry Pi 4, it can erroneously trigger warnings when memory-mapped I/O addresses share sections with RAM, resulting in incorrect DMA mapping behavior. A corrective measure has been implemented, ensuring that the sanity check accurately distinguishes usable RAM from MMIO regions, thereby enhancing the kernel’s integrity and operational reliability.

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