⬢ DragonFlyBSD Kernel Audit
DF-4069 / verdict.json
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{
  "finding_id": "DF-4069",
  "status": "inconclusive",
  "reproduced": 0,
  "impact": "none",
  "confidence": "certain",
  "verdict": "Source-level certain, hardware-gated. vegam_populate_all_graphic_levels() walks dpm_table.sclk_table.count (VBIOS u8 ucNumEntries, unclamped anywhere on the path process_pptables_v1_0.c -> smu7_hwmgr.c -> here) writing GraphicsLevel[i] into a fixed array of SMU75_MAX_LEVELS_GRAPHICS=8 entries (60B each, 480B capacity, offset 236 in the 1956B SMU75_Discrete_DpmTable embedded in kzallocd vegam_smumgr). count=9 is already OOB (into MemoryACPILevel/MemoryLevel); count=255 writes 15,300B from the array start => ~13KB past the entire heap allocation. Sizes proven by a guest-compiled probe against the in-tree headers (run.log). Not runnable on the audit guest: requires a VegaM (AMDGPU_FAMILY_AI polaris-class vegam SKU) GPU fed a crafted powerplay table.",
  "exploit_chain": "",
  "evidence": "probe.c + run.log: sizeof(SMU75_Discrete_GraphicsLevel)=60, capacity=8*60=480B, count=255 -> 15300B; smu75_discrete.h:287; vegam_smumgr.c:886-913,920-922",
  "kernel_refs": [
    "sys/dev/drm/amd/powerplay/smumgr/vegam_smumgr.c:886",
    "sys/dev/drm/amd/powerplay/smumgr/vegam_smumgr.c:906",
    "sys/dev/drm/amd/powerplay/inc/smu75_discrete.h:287",
    "sys/dev/drm/amd/powerplay/hwmgr/smu7_hwmgr.c:689",
    "sys/dev/drm/amd/powerplay/hwmgr/process_pptables_v1_0.c:425"
  ],
  "poc_changes": "n/a (source-level analysis; struct probe written fresh, compiled on guest)",
  "attempts": 2,
  "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": 2,
  "guest_dirty": 0,
  "build_cmd": "cd /tmp && cc -I/usr/src/sys/dev/drm/amd/powerplay/inc -o probe probe.c",
  "run_cmd": "./probe",
  "code_hash": "f7a1c2a04508804db37b7fac0f9eed0a292e293a9b7a26d975c9dc3d8939ca76",
  "notes": "Pass-2 fresh ground: DF-1366/67/68 covered VCE/UVD/CAC/clock-stretcher/AVFS walks only. GraphicsDpmLevelCount=(uint8_t)count at :906 does NOT truncate (count is u8-sourced).",
  "recommended_fix": "Clamp the SCLK level walk (and both follow-up loops + GraphicsDpmLevelCount) to SMU75_MAX_LEVELS_GRAPHICS.",
  "fix_status": "not_testable",
  "fix_baseline_reproduced": 0,
  "fix_patched_reproduced": 0,
  "fix_verdict": "Hardware-gated finding (no AMD VegaM GPU / no LSI mps controller on the audit guest): fix authored at source level (fix.diff) but not build/boot-validated.",
  "fix_evidence": "fix.diff in this pack; authored post-analysis, not hardware-validated."
}