=== PATCHED KERNEL (fix.diff applied; #1: Wed Oct 7 03:43:23 UTC 2026) ===

$ sysctl debug.mddiag=booby        # identical plant: pdp[64] = 0x800000000000 | V
DFRIG: booby planted: pdp[64] = 0x800000000000|V
DFRIG: dump walk will call dump_add_page(0x800000000000) unguarded -> vm_page_dump[0x20000000] = 0xfffff80140000000
panic: DF-5536 rig: intentional panic with booby PD entry
boot() called on cpu#2
Uptime: 2m27s
Physical memory: 4060 MB
Dumping 668 MB: 653 637 621 605 589 573 557 541 525 509 493 477 461 445 429 413 397 381 365 349 333 317 301 285 269 253 237 221 205 189 173 157 141 125 109 93 77 61 45 29 13
Dump complete

RESULT: fix validated. Baseline: Fatal trap 12 (supervisor write at the predicted
bitmap OOB target) -> nested panic, no dump. Patched: the is_dumpable() guards skip
the planted entry, dump completes, savecore extracts the core after reboot.