⬢ DragonFlyBSD Kernel Audit
DF-4372 / verdict.json
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{
  "finding_id": "DF-4372",
  "status": "untested",
  "reproduced": 0,
  "impact": "none",
  "confidence": "certain",
  "verdict": "PoC phase not executed for this Low-severity finding (per audit contract PoC is optional below Medium; additionally the audit VM has no radeon GPU, no /dev/dri, and the VBIOS is not attacker-controllable in a QEMU virtio-gpu VM). Defect is certain from inspection: r600_parse_extended_power_table dereferences usFanTableOffset (r600_dpm.c:893-895, versioned union reads :903-915) and usExtendendedHeaderOffset (r600_dpm.c:1070-1073) with no zero/bounds validation; offset 0 aliases the PowerPlayInfo header as the extended header and out-of-range offsets read past the <=256KiB kmallocd BIOS image. Sibling of DF-1566 (which covers the count/index walks); this covers the container-offset provenance.",
  "exploit_chain": "",
  "evidence": "VERDICT.md; README.md; fix.diff (3-file) verified APPLIES_CLEAN",
  "kernel_refs": [
    "sys/dev/drm/radeon/r600_dpm.c:893",
    "sys/dev/drm/radeon/r600_dpm.c:1070",
    "sys/dev/drm/radeon/r600_dpm.c:1074",
    "sys/dev/drm/radeon/radeon_bios.c:68"
  ],
  "poc_changes": "none (no runnable PoC possible without radeon hardware and a crafted VBIOS)",
  "attempts": 0,
  "guest_uname": "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",
  "runtime_sec": 0,
  "guest_dirty": 0,
  "build_cmd": "",
  "run_cmd": "",
  "code_hash": "",
  "notes": "Low severity sibling of DF-1566 with a distinct missing check (container offsets vs counts/indices). Do not re-test counts here \u2014 DF-1566 owns those.",
  "recommended_fix": "Plumb rdev->bios_size from the allocation sites and validate usFanTableOffset / usExtendendedHeaderOffset (non-zero, within image) before any dereference; gate all six ext-table blocks on the validated header (see fix.diff)",
  "fix_status": "not_testable",
  "fix_baseline_reproduced": 0,
  "fix_patched_reproduced": 0,
  "fix_verdict": "fix.diff authored post-verification (radeon.h + radeon_bios.c + r600_dpm.c); applies cleanly via patch -p1 --dry-run on scratch copies; runtime validation impossible on this VM (no radeon hardware)",
  "fix_evidence": "findings/poc/DF-4372/fix.diff; dry-run output checking file ... radeon.h / radeon_bios.c / r600_dpm.c / DF4372_APPLIES_CLEAN"
}