=== DF-1051 fix-validation: PATCHED kernel ===
Kernel: DragonFly 6.5-DEVELOPMENT #1: Sun Jul 19 16:49:25 UTC 2026
sha256: bcfe20d5ad4accf44f6020bcb9aaf9162c9a4870a0b5d43022553fd6d2861238

=== securelevel=2 + open /dev/sg0 ===
$ ssh dfbsd 'sysctl kern.securelevel=2'
kern.securelevel: -1 -> 2
$ ssh dfbsd 'cd /root/poc/DF-1051 && ./sg_securelevel_panic; echo EXIT=$?'
./sg_securelevel_panic: open /dev/sg0 failed: Operation not permitted
EXIT=1
$ ./dfbsd-qemu/vm.sh status
up                                       <-- GUEST STAYS UP — no panic

=== securelevel=-1 (rebooted) ===
$ ./dfbsd-qemu/vm.sh down && ./dfbsd-qemu/vm.sh up 180
$ ssh dfbsd 'sysctl kern.securelevel; cd /root/poc/DF-1051 && ./sg_securelevel_panic; echo EXIT=$?'
kern.securelevel: -1
./sg_securelevel_panic: opened /dev/sg0 (no panic; securelevel<=1)
EXIT=0                                   <-- normal path also works (open succeeds)