# DF-0096 — REPRODUCED (source-only)

## Verdict
REPRODUCED (source-only)

## Mechanism
sglist_join documented to append second->first but bcopy(first->sg_segs+first_nseg, second->sg_segs+append,...) copies FROM first uninit tail INTO second (reversed args). first->sg_nseg bumped (:615) as if appending to first; the actual data goes the wrong way and second is corrupted.

## Source trace
- File: `sys/kern/subr_sglist.c`
- References: sys/kern/subr_sglist.c:613, sys/kern/subr_sglist.c:615

## 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
Swap bcopy source/dest so it reads from second and writes to first. Matches finding proposal.