MMalloc trace-table exhaustion (>=16384 outstanding allocations) makes Malloc() return NULL in VINUMDEBUG builds, breaking the never-fail M_WAITOK contract the vinum family relies on: unchecked callers NULL-deref (panic) and expand_table's CHECKALLOC longjmps out of crit_enter() without crit_exit() (leaked critical section)

Summary

The debug wrapper invents a failure kmalloc(M_WAITOK) cannot have (table-full -> return 0): unchecked vinumrevive.c callers deref NULL, and expand_table's CHECKALLOC longjmps past its crit_exit (permanent crit leak); the out-of-crit guard + per-CPU bookkeeping also permits a speculative malloced[16384] OOB write on 2 CPUs. VINUMDEBUG-only (stock vinum.ko has no VINUMDEBUG strings - verified on guest) + root. Skip-tracing-when-full fix restores the contract DF-5094 leaned on.