{
  "verdict": "reproduced",
  "impact": "panic",
  "finding_id": "DF-5334",
  "reproduce": {
    "build": "none for baseline panic (device-triggered). For fix validation: cd /usr/src/sys/bus/u4b/net/uether && make && cp uether.ko /boot/kernel/ ; cd ../cdce && make && cp if_cdce.ko /boot/kernel/ (after applying fix.diff to /usr/src)",
    "run": "cd dfbsd-qemu && qemu-img snapshot -a with-src disk.qcow2 && QEMU_EXTRA='-device piix3-usb-uhci,id=uhci0 -netdev user,id=n1 -device usb-net,bus=uhci0.0,netdev=n1' ./vm.sh up 240",
    "expected": "unpatched: serial log shows cdce0 'No valid alternate setting found' then 'Fatal trap 12 ... fault virtual address = 0x0', DDB backtrace uether_ifdetach<-cdce_detach<-cdce_attach, ssh never comes up; patched (fix.diff modules): boots to ssh, clean 'attach returned 6' then ue0 attaches and works, zero Fatal traps"
  },
  "kernel_refs": [
    "sys/bus/u4b/net/if_cdce.c:580",
    "sys/bus/u4b/net/if_cdce.c:610",
    "sys/bus/u4b/net/if_cdce.c:660",
    "sys/bus/u4b/net/if_cdce.c:717-721",
    "sys/bus/u4b/net/if_cdce.c:730-732",
    "sys/bus/u4b/net/if_cdce.c:743",
    "sys/bus/u4b/net/usb_ethernet.c:133-137",
    "sys/bus/u4b/net/usb_ethernet.c:267-305",
    "sys/bus/u4b/net/usb_ethernet.c:278",
    "sys/bus/u4b/net/usb_ethernet.c:281",
    "sys/net/if.c:966",
    "sys/net/if.c:982",
    "sys/net/if_ethersubr.c:666-673"
  ],
  "artifacts": [
    "README.md",
    "VERDICT.md",
    "trigger-attach.sh",
    "serial_drive.py",
    "build.sh",
    "run.sh",
    "build.log",
    "run.log",
    "run.serial.log",
    "run.2.log",
    "panic.txt",
    "env.txt",
    "fix.diff",
    "manifest.json",
    "verdict.json"
  ]
}