⬢ DragonFlyBSD Kernel Audit
DF-3965 / verdict.json
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{
  "finding_id": "DF-3965",
  "status": "not_reproduced",
  "reproduced": 0,
  "impact": "none",
  "confidence": "certain",
  "verdict": "Certain DMA-map lifetime bug, Low on this platform: the three completion callbacks sync/unload the per-SRB io map only inside case IOP_RESULT_SUCCESS (hptiop.c:393-409/547-561/654-668) although every data CCB loads it (2304-2309); all non-success results (BAD_TARGET from every absent-tid bus probe, BUSY, FAIL, CHECK_CONDITION, ...) return the srb to the freelist with the map still loaded, and the next use double-loads it. On bounce-capable tags/platforms the reservation accounting (busdma_machdep.c pagesneeded) accumulates until the bounce pool is exhausted -> permanent CAM_BUSY; on the current amd64 no-bounce io_dmat the leak is bookkeeping-only. Not reproduced: guest lacks the HBA (env.txt).",
  "exploit_chain": "",
  "evidence": "VERDICT.md (load/unload asymmetry + busdma accounting path), trigger.c (deterministic BAD_TARGET source), env.txt (hw.busdma.max_bpages=1024), fix.diff (unload on all completions)",
  "kernel_refs": [
    "sys/dev/raid/hptiop/hptiop.c:2304",
    "sys/dev/raid/hptiop/hptiop.c:393",
    "sys/dev/raid/hptiop/hptiop.c:547",
    "sys/dev/raid/hptiop/hptiop.c:654",
    "sys/dev/raid/hptiop/hptiop.c:457",
    "sys/platform/pc64/x86_64/busdma_machdep.c:616"
  ],
  "poc_changes": "Informational trigger only.",
  "attempts": 1,
  "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": 4,
  "guest_dirty": 0,
  "build_cmd": "guest: cd /usr/src/sys/dev/raid/hptiop && patch -p1 < fix.diff && make   # after make obj",
  "run_cmd": "dfbsd-qemu/vm.sh run_root sysctl hw.busdma.max_bpages hw.busdma.total_bpages; pciconf -lv | grep -i 1103",
  "code_hash": "b2a932eabc042f2d632cb3c4d46159c1cf70d1fa6096df2797b4c2e832430bcc",
  "notes": "Pass-2 finding, checklist item (e). BAD_TARGET probes make the leak deterministic rather than exceptional.",
  "recommended_fix": "Unload/sync the srb dma_map on every completion, not only IOP_RESULT_SUCCESS (fix.diff pattern for all three callbacks).",
  "fix_status": "not_testable",
  "fix_baseline_reproduced": 0,
  "fix_patched_reproduced": 0,
  "fix_verdict": "fix.diff demonstrates the itl hunk (default-arm unload); the mv/mvfrey callbacks need the identical pattern. git apply --check clean fix.diff applied to the guest /usr/src copy and the hptiop.ko module rebuilt clean with -Werror (build.log; combined with the other four hptiop fix.diffs of this batch); runtime validation still impossible without the HBA.",
  "fix_evidence": "fix.diff; fix.diff applied to the guest /usr/src copy and the hptiop.ko module rebuilt clean with -Werror (build.log; combined with the other four hptiop fix.diffs of this batch); runtime validation still impossible without the HBA."
}