Guest: QEMU/KVM x86_64, DragonFly 6.5-DEVELOPMENT

baseline kernel (truncation reproduced):
  DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026
      root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC  x86_64

patched kernel (fix validation):
  DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #1: Wed Oct  7 13:21:14 UTC 2026
      root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC  x86_64
  (sys/bus/cam/cam.c rebuilt with findings/poc/DF-5554/fix.diff via
   `make nativekernel KERNCONF=X86_64_GENERIC` + installkernel + reboot)

compiler: cc 8.3 [DragonFly] Release/2019-02-22
CAM state at test: live ("CAM: finished configuring all busses"; cd0 on ata1
  via atapi-cam, which itself dispatches XPT_CALC_GEOMETRY -> cam_calc_geometry,
  sys/dev/disk/nata/atapi-cam.c:470; root disk vtblk0 non-CAM)
harness: KLD df5554.ko built against the running kernel via
  /usr/src/sys/conf/kmod.mk (calls the PRODUCTION cam_calc_geometry symbol)