{
  "finding_id": "DF-4226",
  "status": "untested",
  "reproduced": 0,
  "impact": "none",
  "confidence": "certain",
  "verdict": "Hardware-gated functional defect (no memory-safety impact, hence impact=none): radeon_legacy_tmds_int_commit (radeon_legacy_encoders.c:775/777) and radeon_legacy_tv_dac_commit (:1146/1148) call radeon_{atom,combios}_output_lock with true (LOCK) where the prepare/commit contract and all three sibling commit functions in the same file (lvds:169, primary_dac:578, tmds_ext:940) pass false (UNLOCK). After a DVI/TV modeset the output stays locked and later DPMS/modeset register programming is inhibited — display DoS until re-init, triggerable by a DRM master. Requires r100-r500 hardware; the QEMU guest has Bochs VGA and no DRM device, so no runtime test is possible or needed: the asymmetry is fully established from source.",
  "exploit_chain": "",
  "evidence": "VERDICT.md side-by-side of the five prepare/commit pairs in the file; fix.diff flips the four arguments to false, restoring parity with siblings and upstream Linux.",
  "kernel_refs": [
    "sys/dev/drm/radeon/radeon_legacy_encoders.c:775",
    "sys/dev/drm/radeon/radeon_legacy_encoders.c:1146",
    "sys/dev/drm/radeon/radeon_legacy_encoders.c:169",
    "sys/dev/drm/radeon/radeon_legacy_encoders.c:940"
  ],
  "poc_changes": "n/a (source-level finding)",
  "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": "n/a",
  "run_cmd": "n/a",
  "code_hash": "",
  "notes": "Skipped per contract (Low severity, hardware-gated, no runnable PoC). Upstream Linux passes false in both commit functions.",
  "recommended_fix": "Pass false to radeon_{atom,combios}_output_lock in radeon_legacy_tmds_int_commit and radeon_legacy_tv_dac_commit (lines 775/777/1146/1148).",
  "fix_status": "not_testable",
  "fix_baseline_reproduced": 0,
  "fix_patched_reproduced": 0,
  "fix_verdict": "No radeon hardware on the guest; fix is a four-argument change restoring exact parity with the three correct sibling commit functions in the same file.",
  "fix_evidence": "fix.diff; source comparison in VERDICT.md"
}