# DF-0057 — REPRODUCED (source-only, root-only kldload)

## Verdict
REPRODUCED (source-only, root-only kldload)

## Mechanism
link_elf_load_file at :590 does kmalloc(e_shnum*e_shentsize) but no e_shentsize==sizeof(Elf_Shdr) check; shdr[i] indexed with 64-byte stride. If e_shentsize<64 the allocation is too small → shdr[i] OOB read.

## Source trace
- File: `sys/kern/link_elf.c`
- References: sys/kern/link_elf.c:590, sys/kern/link_elf.c:593

## 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
Reject e_shentsize != sizeof(Elf_Shdr). Matches finding proposal.