DF-3089 / verdict.json
{ "finding_id": "DF-3089", "status": "not_reproduced", "reproduced": 0, "impact": "none", "confidence": "certain", "verdict": "Line-accurate confirmation; no runtime manifestation exists on this platform/compiler (both copies are absorbed by struct padding). NFSKERBKEY_T is u_char[2] (rpcv2.h:133); both nfs_getauth and nfs_savenickauth declare it as a by-value array parameter, so sizeof(NFSKERBKEY_T) inside the function is the pointer size 8: nfs_getauth bcopys 8 bytes out of the 2-byte nmp->nm_key (6-byte in-struct overread, nfs_syscalls.c:1075) and nfs_savenickauth bcopys 8 bytes into the 2-byte nuidp->nu_key at offset ~284 of the 320-byte struct nfsuid (6 bytes into allocator padding, :1208). Fix copies sizeof(member) (2) at both sites; compiled in the F40FIX build.", "exploit_chain": "", "evidence": "VERDICT.md with path:line citations; run.log where a live demo exists; fix.diff", "kernel_refs": [ "sys/vfs/nfs/rpcv2.h:133", "sys/vfs/nfs/nfs_syscalls.c:1075", "sys/vfs/nfs/nfs_syscalls.c:1208" ], "poc_changes": "n/a - padding-absorbed on this ABI", "attempts": 0, "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": 30, "guest_dirty": 0, "build_cmd": "see build.sh", "run_cmd": "see run.sh", "code_hash": null, "notes": "", "recommended_fix": "bcopy sizeof(nmp->nm_key)/sizeof(nuidp->nu_key) instead of the decayed parameter type", "fix_status": "compile_validated", "fix_verdict": "fix.diff applied in the F40FIX verification kernel build (RC=0, zero -Werror errors); no runtime A/B for this item (line-certain hardening)" } |