nilfs2: extract 3.x volumes (closes #64)

CMakeLists.txt

@@ -92,6 +92,7 @@ add_executable(moria
   src/extract/android_sparse.cpp
   src/extract/ext.cpp
   src/extract/reiserfs.cpp
+  src/extract/nilfs2.cpp
   src/extract/jffs2.cpp
   src/extract/ubifs.cpp
   src/extract/tar.cpp
@@ -256,6 +257,7 @@ if(Python3_Interpreter_FOUND)
     test_esp32_nvs
     test_legacy_fs
     test_reiserfs_extract
+    test_nilfs2_extract
     test_romfs_sizecap
     test_luks
     test_lzma

README.md

@@ -48,7 +48,7 @@ moria --help
 
 Unpacked in-process, no external tools and no sudo:
 
-- **Filesystems:** SquashFS, ext2/3/4, F2FS, FAT12/16/32, exFAT, NTFS, HFS+/HFSX, XFS, btrfs, JFFS2, UBI/UBIFS, romfs, YAFFS2, cramfs, EROFS, ReiserFS
+- **Filesystems:** SquashFS, ext2/3/4, F2FS, FAT12/16/32, exFAT, NTFS, HFS+/HFSX, XFS, btrfs, JFFS2, UBI/UBIFS, romfs, YAFFS2, cramfs, EROFS, ReiserFS, NILFS2
 - **Archives and images:** ZIP, tar, cpio, MS-CAB (stored/MSZIP/LZX), CFBF compound files / Windows Installer `.msi`, ISO 9660, Android sparse, Android boot
 - **Kernels and wrappers:** U-Boot uImage, U-Boot FIT, Windows CE XIP ROM (nk.bin / .cos), standalone gzip / xz / zstd / lz4 streams, Ingenic jzlzma (hardware LZ77)
 - **Firmware packages:** RAE Systems / Honeywell RFP (section table; LZARI-decompresses each section); Artosyn OTRA (AR8030 / VT4 / VR04; SHA-256-verified, LZO1X-decompresses each partition, or exposes the raw flash body on flat images)

fuzz/build.sh

@@ -11,7 +11,7 @@ mapfile -t SRCS < <(find src -name '*.cpp' ! -name 'main.cpp' | sort)
 # Xcode clang lacks the libFuzzer runtime; override with a clang that has it
 # (e.g. CXX=/opt/homebrew/opt/llvm/bin/clang++ on macOS).
 CXX="${CXX:-clang++}"
-for target in fuzz_scan fuzz_esp32_part fuzz_esp32_nvs fuzz_lzx fuzz_reiserfs; do
+for target in fuzz_scan fuzz_esp32_part fuzz_esp32_nvs fuzz_lzx fuzz_reiserfs fuzz_nilfs2; do
   "$CXX" -std=c++20 -O1 -g -fsanitize=fuzzer,address -I src -I third_party \
     -DFT_FUZZ_SIGDIR="\"$PWD/signatures\"" \
     "${SRCS[@]}" "fuzz/${target}.cpp" -o "$target"

fuzz/fuzz_nilfs2.cpp

@@ -0,0 +1,32 @@
+// fuzz_nilfs2.cpp — libFuzzer entry point for the NILFS2 extractor.
+// Feeds fuzzer bytes to the parse-only read chain (superblock selection, super
+// root, DAT translation, cpfile, ifile, directory walk, block maps) with a
+// partition at offset 0, and to the full scan pipeline so the identify/validator
+// path also sees adversarial input (issue #64).
+//
+// Build via fuzz/build.sh. Run: ./fuzz_nilfs2 -max_total_time=60
+#include <cstddef>
+#include <cstdint>
+#include <span>
+
+#include "extract/nilfs2.hpp"
+#include "reader.hpp"
+#include "scan.hpp"
+#include "sigload.hpp"
+
+#ifndef FT_FUZZ_SIGDIR
+#define FT_FUZZ_SIGDIR "signatures"
+#endif
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    static const ft::LoadResult sigs = ft::load_signatures(FT_FUZZ_SIGDIR);
+    ft::Reader reader(std::span<const uint8_t>(data, size));
+
+    // Direct: the whole read chain with the filesystem at offset 0.
+    ft::nilfs2_probe(reader, 0);
+
+    // Via the pipeline: magic-driven identification on the raw bytes.
+    auto findings = ft::scan(reader, sigs.signatures);
+    (void)findings;
+    return 0;
+}

moria.1

@@ -13,7 +13,7 @@ embedded formats (filesystems, containers, bootloaders, executables,
 compression, media) with byte offsets and confidence tiers. It is
 identification-first; with
 .B \-\-extract
-it also unpacks SquashFS, ext2/3/4, F2FS, JFFS2, UBIFS, romfs, YAFFS2, cramfs, FAT, exFAT, NTFS, HFS+, XFS, btrfs, EROFS, ReiserFS, and ISO9660 filesystems, ZIP/tar/cpio/MS-CAB archives, CFBF compound files (Windows Installer .msi), U-Boot uImage/FIT containers, Windows CE XIP ROM images and registry hives, RAE Systems/Honeywell RFP firmware packages (LZARI-decompressing their sections), and Ingenic jzlzma-compressed kernel/rootfs images (hardware LZ77)
+it also unpacks SquashFS, ext2/3/4, F2FS, JFFS2, UBIFS, romfs, YAFFS2, cramfs, FAT, exFAT, NTFS, HFS+, XFS, btrfs, EROFS, ReiserFS, NILFS2, and ISO9660 filesystems, ZIP/tar/cpio/MS-CAB archives, CFBF compound files (Windows Installer .msi), U-Boot uImage/FIT containers, Windows CE XIP ROM images and registry hives, RAE Systems/Honeywell RFP firmware packages (LZARI-decompressing their sections), and Ingenic jzlzma-compressed kernel/rootfs images (hardware LZ77)
 internally (no sudo). Every other format is still identified and located by offset, ready for another tool such as binwalk.
 .PP
 Output is human-readable by default. A single file shows a findings tree
@@ -55,7 +55,7 @@ List tar/cpio/zip/MS-CAB member names and sizes, or a Windows CE ROM's modules a
 .SS Extract
 .TP
 .BR \-e ", " \-\-extract
-Unpack identified SquashFS, ext2/3/4, F2FS, JFFS2, UBIFS (incl. UBI), romfs, YAFFS2, cramfs, FAT, exFAT, NTFS, EROFS, ReiserFS, and ISO9660 filesystems, ZIP/tar/cpio/MS-CAB archives, CFBF compound files such as Windows Installer .msi packages, U-Boot uImage/FIT containers, Android boot/sparse images, Windows CE XIP ROM images, Windows CE registry hives, and RAE Systems/Honeywell RFP firmware packages into
+Unpack identified SquashFS, ext2/3/4, F2FS, JFFS2, UBIFS (incl. UBI), romfs, YAFFS2, cramfs, FAT, exFAT, NTFS, EROFS, ReiserFS, NILFS2, and ISO9660 filesystems, ZIP/tar/cpio/MS-CAB archives, CFBF compound files such as Windows Installer .msi packages, U-Boot uImage/FIT containers, Android boot/sparse images, Windows CE XIP ROM images, Windows CE registry hives, and RAE Systems/Honeywell RFP firmware packages into
 .IR file .extracted/
 (one subdir per region, named
 .IR 0x<offset>\-<type> ).

src/extract/manifest.cpp

@@ -24,6 +24,7 @@
 #include "extract/fat.hpp"
 #include "extract/iso9660.hpp"
 #include "extract/jffs2.hpp"
+#include "extract/nilfs2.hpp"
 #include "extract/ntfs.hpp"
 #include "extract/otra.hpp"
 #include "extract/rae_rfp.hpp"
@@ -58,6 +59,7 @@ Extractor find_extractor(const std::string& type) {
     if (type == "romfs") return extract_romfs;
     if (type == "cramfs") return extract_cramfs;
     if (type == "reiserfs") return extract_reiserfs;
+    if (type == "nilfs2") return extract_nilfs2;
     if (type == "erofs") return extract_erofs;
     if (type == "f2fs") return extract_f2fs;
     if (type == "android_sparse") return extract_android_sparse;