CVE-2026-10677 Kernel heap memory leak in `z_vrfy_k_poll()` lets an unprivileged user thread exhaust the kernel resource pool

The CONFIGUSERSPACE syscall verifier zvrfykpoll in kernel/poll.c allocates a kernel-side copy of the user-supplied kpollevent via zthreadmalloc and then validates each event's object handle. Before this fix, validation used KOOPSKSYSCALLOBJ... inline inside the loop, which kills the calling threa...