{
  "finding_id": "DF-3461",
  "title": "in6_cksum() sanity check bypassable via u32 wrap of off+len (defense-in-depth)",
  "verdict": "untested",
  "impact": "none",
  "reproduce": {
    "build": "ssh -F dfbsd-qemu/config dfbsd 'cat > /tmp/wrap_demo.c' < wrap_demo.c && vm.sh run_root 'cd /tmp && cc -O2 -Wall -o wrap_demo wrap_demo.c'",
    "run": "vm.sh run_root 'cd /tmp && ./wrap_demo'",
    "expected": "off=0xffffffff len=41 -> off+len=0x00000028 (40) wrapped=1 / sanity check BYPASSED / after walk: m=0x0 -> mtod(NULL) deref"
  },
  "kernel_refs": [
    "sys/netinet6/in6_cksum.c:91",
    "sys/netinet6/in6_cksum.c:116",
    "sys/netinet6/in6_cksum.c:150",
    "sys/netinet6/in6_cksum.c:157",
    "sys/netinet6/in6_cksum.c:285"
  ],
  "artifacts": [
    "README.md", "VERDICT.md", "wrap_demo.c", "build.sh",
    "build.log", "run.log", "env.txt", "fix.diff",
    "manifest.json", "verdict.json"
  ]
}