# DF-0030 — REPRODUCED (source-only)

## Verdict
REPRODUCED (source-only)

## Mechanism
jrecord_write_path walks namecache parent chain twice; if nc_nlen grows between passes (concurrent rename), the bounds check at :1251 frees the buffer and goto again restarts pass 1 indefinitely.

## Source trace
- File: `sys/kern/vfs_journal.c`
- References: sys/kern/vfs_journal.c:1251, sys/kern/vfs_journal.c:1254

## PoC changes
Source-only confirmation; no runtime PoC required for this Low-severity / HW-gated /
root-only finding (per AGENT.md guidance: "source-only confirmation acceptable").
The fix.diff was authored against the cited lines and validated by a single combined
40-finding kernel build that completed rc=0 with zero -Werror warnings.

## Fix validation
- fix.diff applies cleanly with `git apply --check -p1` and `patch -p1 --forward`.
- Combined kernel build (`make -j6 nativekernel KERNCONF=X86_64_GENERIC`) succeeded
  rc=0 with all 39 Low-severity fix.diffs applied simultaneously.
- Build log: `../../combined_40_low_severity_kernel_build.log` (NK_DONE rc=0).

## Recommended fix
Bound the number of retries with a counter; after 4 retries, return without emitting a leaf rather than spinning. Hardening; original loop is correct under stable topology.