# DF-0093 — REPRODUCED (source-only)

## Verdict
REPRODUCED (source-only)

## Mechanism
sys_shmctl IPC_STAT at :424 copyout(shmseg,uap->buf,sizeof(inbuf)) copies entire in-kernel struct shmid_ds incl void *shm_internal (shm.h:83) which holds kmalloc heap ptr shm_handle (set :550). Any process with IPC_R incl creator/owner (shm_perm.mode 0444) gets a kernel heap pointer.

## Source trace
- File: `sys/kern/sysv_shm.c`
- References: sys/kern/sysv_shm.c:424, sys/sys/shm.h:83

## 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
Make a sanitized copy with shm_internal=NULL before copyout. Matches finding proposal.