{
  "finding_id": "DF-3785",
  "status": "reproduced",
  "reproduced": 1,
  "impact": "dos",
  "confidence": "certain",
  "verdict": "REPRODUCED at source level (guard-arithmetic harness): (offset=-32511, count=32767) passes the exact driver guard, the loop writes 32767 bytes into bytes[256]; first OOB byte lands at ioctl-buffer offset 260 of a 260-byte allocation. The i2c/EEPROM data path requires real hardware (absent on this guest).",
  "exploit_chain": "open /dev/tuner0 (0444) -> (optionally prime EEPROM via BT848_I2CWR) -> BT848_REEPROM{offset=-32511, count=32767} -> 32.5 KiB controlled heap overflow past a 260-byte M_IOCTLOPS allocation.",
  "evidence": "run.log: guard evaluation (256 > 256 = false -> PASSES) and the 32511-bytes-past-buffer result; canary inspection.",
  "kernel_refs": [
    "sys/dev/video/bktr/bktr_core.c:2086",
    "sys/dev/video/bktr/bktr_card.c:433",
    "sys/dev/video/bktr/bktr_card.c:441",
    "sys/dev/video/bktr/ioctl_bt848.h:93",
    "sys/kern/sys_generic.c:687"
  ],
  "poc_changes": "first harness version smashed its own stack buffer (SIGSEGV) - switched to an mmapd region",
  "attempts": 3,
  "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": 200,
  "guest_dirty": 0,
  "build_cmd": "cc -O -Wall -o harness harness_eeprom.c",
  "run_cmd": "./harness",
  "code_hash": "9e813c8b4e5a6edad997c1ccbbcf662e3f13370c068933cecfdc3a43780d44b3",
  "notes": "EEPROM presence required on real hw; content control additionally uses DF-1217s unpriv I2C write.",
  "recommended_fix": "Validate offset/count against sizeof(bytes) in the ioctl and fix the signed guard in readEEProm (fix.diff)",
  "fix_status": "not_testable",
  "fix_baseline_reproduced": 1,
  "fix_patched_reproduced": 0,
  "fix_verdict": "Runtime fix validation impossible on this guest (no Bt848/878 hardware, driver not in GENERIC, no module dir). fix.diff applies cleanly to sys/ and the patched bktr KLD module compiles with -Werror on the guests /usr/src (fix_build.log).",
  "fix_evidence": "fix.diff; fix_build.log (all-8-fixes module build, MAKE_RC=0)"
}