[200-run sweep, kernel #0: the leaked slot tracks the run index — i.e. the previous
syscall's leftover stack, not anything the caller set. Distinct observed values:
0x0,0x3,0x4,0x5,...,0x22,... i.e. loop counters from the previous vquotactl's
internalize/externalize frames. Sample (uniq -c style, all counts 1):
run 80: 0x0f | run 81: 0x10 | run 88: 0x17 | run 97: 0x20 | run 99: 0x22 | ... ]