{
  "finding_id": "DF-3972",
  "status": "inconclusive",
  "reproduced": 0,
  "impact": "none",
  "confidence": "certain",
  "verdict": "Source-certain NULL-deref: rdev->pm.dpm.boot_ps is only set under a BOOT-classified, fully-parsed VBIOS state (rv770_dpm.c:2172 within the ucStateEntrySize>1 block at 2304); radeon_pm_init_dpm ignores btc_dpm_inits return (radeon_pm.c:1448) and btc_dpm_enable dereferences the NULL boot_ps at btc_dpm.c:2446/2451/2485 via cypress_populate_smc_initial_state (cypress_dpm.c:1242,1266). Cannot reproduce: the QEMU guest has no AMD GPU (env.txt), and the trigger bytes live in the cards VBIOS PowerPlayInfo table. Same enabling sequence as the reproduced ni twin DF-3754.",
  "exploit_chain": "",
  "evidence": "VERDICT.md full trace; env.txt (guest PCI inventory: no 0x1002 device, no /dev/dri); kernel_refs below",
  "kernel_refs": [
    "sys/dev/drm/radeon/btc_dpm.c:2377",
    "sys/dev/drm/radeon/btc_dpm.c:2446",
    "sys/dev/drm/radeon/btc_dpm.c:2451",
    "sys/dev/drm/radeon/btc_dpm.c:2485",
    "sys/dev/drm/radeon/btc_dpm.c:2526",
    "sys/dev/drm/radeon/rv770_dpm.c:2172",
    "sys/dev/drm/radeon/rv770_dpm.c:2304",
    "sys/dev/drm/radeon/radeon_pm.c:1448",
    "sys/dev/drm/radeon/cypress_dpm.c:1242"
  ],
  "poc_changes": "No PoC built: hardware-gated (Barts/Turks/Caicos VBIOS required). Evidence pack is a line-level source trace instead.",
  "attempts": 1,
  "guest_uname": "DragonFly dfbsd 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": 30,
  "guest_dirty": 0,
  "build_cmd": "",
  "run_cmd": "",
  "code_hash": "",
  "notes": "Family twin of DF-3610(si)/DF-3646(ci)/DF-3754(ni)/DF-3953(kv), btc file. DPM default-enabled. Physical-access/crafted-VBIOS threat model; kernel panic at drm attach.",
  "recommended_fix": "Validate rdev->pm.dpm.boot_ps != NULL after rv7xx_parse_power_table in btc_dpm_init and propagate btc_dpm_init failure in radeon_pm_init_dpm (radeon_pm.c:1448).",
  "fix_status": "not_testable",
  "fix_baseline_reproduced": null,
  "fix_patched_reproduced": null,
  "fix_verdict": "fix.diff authored (boot_ps guard + error propagation) but not build-testable: guest lacks any radeon GPU.",
  "fix_evidence": "findings/poc/DF-3972/fix.diff"
}