DragonFlyBSD Kernel Audit
DF-0017 / env.txt
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 DF-0017 — guest environment for the verification
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uname -a:
  DragonFly dfbsd 6.5-DEVELOPMENT DragonFly v6.5.0.1712.g89e6a-DEVELOPMENT #1: Mon Jun 29 14:18:01 UTC 2026     root@ephemeral-5c2002c44b6c:/usr/obj/usr/src/sys/X86_64_GENERIC  x86_64

compiler:
  cc 8.3 [DragonFly] Release/2019-02-22

kernel config: X86_64_GENERIC (master DEV build of the audited tree)

relevant sysctl / state:
  kdmsg.debug: 1
  kern.sync_on_panic: 0
  kern.coredump: 1
  LWKT thread stack = LWKT_THREAD_STACK = UPAGES*PAGE_SIZE = 4*4096 = 16384 bytes
    (sys/sys/thread.h:472, sys/cpu/x86_64/include/param.h:126 UPAGES=4)
    -- NO guard page (kmem_alloc_stack in sys/vm/vm_extern.h:131 is just
       kmem_alloc1(..|KM_STACK); stack overflow runs into adjacent kernel
       memory and double-faults).

console: comconsole (set via /boot/loader.conf `console="comconsole"` so the
         headless guest's panic + DDB output is captured on the QEMU serial
         line -> dfbsd-qemu/boot.log; default vidconsole is -display none).

disk device used: /dev/vbd0  (raw whole-disk cdev; root:operator crw-r-----)
  - vbd0 is the root disk; its DMSG disk iocom (dp->d_iocom) is what
    DIOCRECLUSTER attaches to (sys/kern/subr_disk.c:1191 ->
    disk_iocom_ioctl -> disk_iocom_reconnect -> kdmsg_iocom_reconnect).
  - unprivileged maxx (uid 1001, not in operator) CANNOT open /dev/vbd0
    (Permission denied) -> local vector needs root/operator.

hammer2 daemon (the relay that makes this remotely reachable):
  pid 68, "hammer2: hammer2 autoconn_thread", listens on TCP *:987.
  At boot it connects every disk iocom via DIOCRECLUSTER
  (sbin/hammer2/cmd_service.c:898) and relays peer DMSG traffic between
  TCP 987 clients and the kernel disk iocom.  Killing it (pkill -9 -x
  hammer2) is required to free the disk iocom for a direct local
  DIOCRECLUSTER (see VERDICT.md "Setup" section).

root fs: hammer2 on vbd0s1d (hammer2 has its OWN kernel iocom, hmp->iocom,
  separate from the disk d_iocom; killing the userland daemon does not
  affect the mounted root fs).