vmalloc cleanup

The vmalloc cleanup tag covers discussions around the Linux kernel's handling of virtual memory allocation cleanup, particularly in the context of KASAN (Kernel Address Sanitizer) and RCU (Read-Copy-Update) stalls. A notable thread addresses CVE-2026-43292, a vulnerability where vmalloc cleanup could monopolize CPU time when CONFIG_PAGE_OWNER and KASAN shadow-page freeing collided, leading to RCU stalls and potential system unavailability. This issue is relevant for administrators running Linux guests, developer workstations, CI fuzzing farms, or Windows-adjacent infrastructure through WSL and Hyper-V. The tag focuses on kernel stability, debugging, and performance impacts of vmalloc operations.