BUILD_OK
DF-4610 neomagic mixer-UAF trigger preconditions:
  1. PCI audio function 10c8:8005 (NM256AV) or 10c8:8006 (NM256ZX) present
  2. attach reaches mixer_init() successfully (AC97 codec answers)
  3. bus_alloc_resource_any(IRQ) or snd_setup_intr() fails (neomagic.c:697-703),
     or pcm_register() fails (neomagic.c:709)
  4. unprivileged user opens the surviving 0666 /dev/mixerN
     -> mixer_ops -> freed snd_mixer/ac97_info/sc

This guest: see pciconf output in run.log / env.txt.
/dev/mixer0 exists (belongs to attached pcm driver, NOT neomagic here)
probe done
---PCICONF---
NO_NEOMAGIC_PCI_FUNCTION
Installed devices:
pcm0: <Generic (0x1af40022) (Analog)> (play/rec) default
crw-rw-rw-  1 root  wheel   34, 0x000000ff Sep 22 05:04 /dev/mixer
crw-rw-rw-  1 root  wheel   34, 0x00000000 Sep 22 05:04 /dev/mixer0