Local service interruption via leaked CPU-node reference

Resource-management flaw in Linux kernel 6.11 allows local users to interrupt service during RISC-V cache-information population. In arch/riscv/kernel/cacheinfo.c, populate_cache_leaves() acquires a CPU device-tree node before its ACPI branch returns early, so that branch skips of_node_put() and leaves an incorrect reference count; the same code also fails to handle acquisition errors. The affected path requires a RISC-V system using ACPI, and the published impact is availability-only service interruption rather than data access or modification.