# DF-0111 — REPRODUCED (source-only)

## Verdict
REPRODUCED (source-only)

## Mechanism
kvsscanf CT_CHAR non-suppress branch at :308 does bcopy(inp,va_arg(ap,char*),width) without checking width<=inr. SUPPRESS branch at :292 correctly clamps to min(inr,width). If width>inr (e.g. %5c on 3-char input), reads past NUL terminator into adjacent kernel memory.

## Source trace
- File: `sys/kern/subr_scanf.c`
- References: sys/kern/subr_scanf.c:292, sys/kern/subr_scanf.c:308

## 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
Clamp copy length to inr like the SUPPRESS branch does. Matches finding proposal.