Linux Kernel Vulnerability Affecting ARM64 SMMU/ATS Functionality

CVE-2026-43486

What is CVE-2026-43486?

A vulnerability in the Linux kernel for ARM64 architecture could cause incorrect handling of access flags during memory operations. The issue arises when ptep_get() misinterprets the state of page table entries (PTEs), leading to incorrect no-op checks that may trigger infinite fault loops in specific scenarios. This flaw particularly affects systems without dynamic buffer management (DBM) support or SMMUs configured in particular ways, as the gathered access flag view may not accurately reflect the effective state of each sub-PTE. Proper fixing involves direct checks on each PTE rather than relying solely on gathered values, which ensures consistent memory access and avoids potential operational disruptions.

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