DF-2682 decisive run -- serial console (dfbsd-qemu boot.log), stock INVARIANTS
kernel #0 Thu Jul 2 06:02:54 UTC 2026, unprivileged harness sigio_uaf (uid 1001).
(Console text recovered before boot.log rotation; verbatim.)

Fatal user address access from kernel mode from sigio_uaf at ffffffff80662073

Fatal trap 12: page fault while in kernel mode
cpuid = 2; lapic id = 2
fault virtual address	= 0x40
fault code		= supervisor read data, page not present
instruction pointer	= 0x8:0xffffffff80662073
stack pointer	        = 0x10:0xfffff801166db5a0
frame pointer	        = 0x10:0xfffff801166db5c8
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 0, def32 0, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 850
current thread          = pri 6 
kernel: type 12 trap, code=0

CPU2 stopping CPUs: 0x0000003b
 stopped
Stopped at      pgsigio+0x13:   movl    0x40(%rax),%eax
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