⬢ DragonFlyBSD Kernel Audit
DF-4457 / manifest.json
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{
  "finding_id": "DF-4457",
  "title": "cmi_attach error path after mixer_init leaves a live 0666 /dev/mixerN pointing at freed sc (UAF on open/ioctl) — DF-4156 family, 7th instance",
  "verdict": "inconclusive",
  "impact": "none",
  "confidence": "certain",
  "reproduce": {
    "build": "cd /usr/src/sys/dev/sound/driver/cmi && make obj && make   (guest cc 8.3, -Werror)",
    "run": "sh run.sh   (guest: proves hardware gate); sh trigger.hw.sh (real CMI8738 hardware)",
    "expected": "On hardware: failed attach after mixer_init leaves dangling 0666 /dev/mixerN over freed sc; unprivileged open/ioctl dispatches through freed M_DEVBUF chunk. On this guest: no CMedia device, snd_cmi cannot load — runtime reproduction impossible."
  },
  "kernel_refs": [
    "sys/dev/sound/pci/cmi.c:986",
    "sys/dev/sound/pci/cmi.c:989",
    "sys/dev/sound/pci/cmi.c:1004",
    "sys/dev/sound/pci/cmi.c:1016",
    "sys/dev/sound/pcm/mixer.c:730",
    "sys/dev/sound/pcm/mixer.c:78",
    "sys/dev/sound/pcm/sound.c:1021",
    "sys/dev/sound/pcm/sound.c:1027"
  ],
  "artifacts": [
    "README.md", "VERDICT.md", "trigger.hw.sh", "run.sh", "build.sh",
    "build.log", "run.log", "guest_check.log", "env.txt", "fix.diff",
    "manifest.json", "verdict.json"
  ]
}