Kernel memory leak via under-released folio references

A memory leak in mm/huge_memory in Linux allows attackers to retain kernel memory by truncating files on a qualifying filesystem. The beyond-EOF path calls folio_put() for an after-split large folio instead of dropping folio_nr_pages(folio) page-cache references, so the folio cannot be freed. Triggering the leak requires a filesystem block size larger than the system page size and a truncation that splits the folio to a nonzero order; the bounded consequence is progressive kernel-memory consumption.