fox-it · Schamper · Jun 18, 2025 · Jun 16, 2025 · Jun 17, 2025 · Jun 18, 2025
diff --git a/.gitattributes b/.gitattributes
@@ -0,0 +1 @@
+tests/_data/** filter=lfs diff=lfs merge=lfs -text
diff --git a/.gitignore b/.gitignore
@@ -1,11 +1,12 @@
 coverage.xml
 .coverage
+build/
 dist/
 .eggs/
 *.egg-info/
 *.pyc
 __pycache__/
 .pytest_cache/
-tests/docs/api
-tests/docs/build
+tests/_docs/api
+tests/_docs/build
 .tox/
diff --git a/dissect/squashfs/c_squashfs.py b/dissect/squashfs/c_squashfs.py
@@ -5,7 +5,8 @@
 from dissect.cstruct import cstruct
 
 squashfs_def = """
-#define SQUASHFS_MAGIC  0x73717368
+#define SQUASHFS_MAGIC          0x73717368
+#define SQUASHFS_MAGIC_SWAP     0x68737173
 
 /* size of metadata (inode and directory) blocks */
 #define SQUASHFS_METADATA_SIZE  8192

diff --git a/dissect/squashfs/squashfs.py b/dissect/squashfs/squashfs.py
@@ -33,6 +33,9 @@ def __init__(self, fh: BinaryIO):
 
         sb = c_squashfs.squashfs_super_block(fh)
         if sb.s_magic != c_squashfs.SQUASHFS_MAGIC:
+            if sb.s_magic == c_squashfs.SQUASHFS_MAGIC_SWAP:
+                raise NotImplementedError("Unsupported squashfs pre-4.0 big-endian filesystem")
+
             raise ValueError("Invalid squashfs superblock")
 
         # Only support squashfs 4.x for now

diff --git a/pyproject.toml b/pyproject.toml
@@ -98,7 +98,7 @@ select = [
 ignore = ["E203", "B904", "UP024", "ANN002", "ANN003", "ANN204", "ANN401", "SIM105", "TRY003"]
 
 [tool.ruff.lint.per-file-ignores]
-"tests/docs/**" = ["INP001"]
+"tests/_docs/**" = ["INP001"]
 
 [tool.ruff.lint.isort]
 known-first-party = ["dissect.squashfs"]

diff --git a/tests/_data/gzip-opts.sqfs b/tests/_data/gzip-opts.sqfs
diff --git a/tests/_data/gzip.sqfs b/tests/_data/gzip.sqfs
diff --git a/tests/_data/lz4.sqfs b/tests/_data/lz4.sqfs
diff --git a/tests/_data/lzma.sqfs b/tests/_data/lzma.sqfs
diff --git a/tests/_data/lzo.sqfs b/tests/_data/lzo.sqfs
diff --git a/tests/_data/xz.sqfs b/tests/_data/xz.sqfs
diff --git a/tests/_data/zstd.sqfs b/tests/_data/zstd.sqfs
diff --git a/tests/docs/Makefile → tests/_docs/Makefile b/tests/docs/Makefile → tests/_docs/Makefile
diff --git a/tests/docs/conf.py → tests/_docs/conf.py b/tests/docs/conf.py → tests/_docs/conf.py
@@ -1,3 +1,5 @@
+project = "dissect.squashfs"
+
 extensions = [
     "autoapi.extension",
     "sphinx.ext.autodoc",

diff --git a/tests/docs/index.rst → tests/_docs/index.rst b/tests/docs/index.rst → tests/_docs/index.rst
diff --git a/tests/conftest.py b/tests/conftest.py
@@ -26,34 +26,34 @@ def open_file_gz(name: str, mode: str = "rb") -> Iterator[BinaryIO]:
 
 @pytest.fixture
 def gzip_sqfs() -> Iterator[BinaryIO]:
-    yield from open_file("data/gzip.sqfs")
+    yield from open_file("_data/gzip.sqfs")
 
 
 @pytest.fixture
 def gzip_opts_sqfs() -> Iterator[BinaryIO]:
-    yield from open_file("data/gzip-opts.sqfs")
+    yield from open_file("_data/gzip-opts.sqfs")
 
 
 @pytest.fixture
 def lz4_sqfs() -> Iterator[BinaryIO]:
-    yield from open_file("data/lz4.sqfs")
+    yield from open_file("_data/lz4.sqfs")
 
 
 @pytest.fixture
 def lzma_sqfs() -> Iterator[BinaryIO]:
-    yield from open_file("data/lzma.sqfs")
+    yield from open_file("_data/lzma.sqfs")
 
 
 @pytest.fixture
 def lzo_sqfs() -> Iterator[BinaryIO]:
-    yield from open_file("data/lzo.sqfs")
+    yield from open_file("_data/lzo.sqfs")
 
 
 @pytest.fixture
 def xz_sqfs() -> Iterator[BinaryIO]:
-    yield from open_file("data/xz.sqfs")
+    yield from open_file("_data/xz.sqfs")
 
 
 @pytest.fixture
 def zstd_sqfs() -> Iterator[BinaryIO]:
-    yield from open_file("data/zstd.sqfs")
+    yield from open_file("_data/zstd.sqfs")
diff --git a/tests/data/gzip-opts.sqfs b/tests/data/gzip-opts.sqfs
diff --git a/tests/data/gzip.sqfs b/tests/data/gzip.sqfs
diff --git a/tests/data/lz4.sqfs b/tests/data/lz4.sqfs
diff --git a/tests/data/lzma.sqfs b/tests/data/lzma.sqfs
diff --git a/tests/data/lzo.sqfs b/tests/data/lzo.sqfs
diff --git a/tests/data/xz.sqfs b/tests/data/xz.sqfs
diff --git a/tests/data/zstd.sqfs b/tests/data/zstd.sqfs
diff --git a/tests/test_squashfs.py b/tests/test_squashfs.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from io import BytesIO
+
 import pytest
 
 from dissect.squashfs.c_squashfs import c_squashfs
@@ -75,3 +77,20 @@ def test_squashfs(sqfs: str, compression_id: int, request: pytest.FixtureRequest
     sqfs = SquashFS(request.getfixturevalue(sqfs))
     assert sqfs.sb.compression == compression_id
     _verify_filesystem(sqfs)
+
+
+def test_squashfs_unsupported_bigendian_3_0() -> None:
+    """Test if we correctly detect a SquashFS 3.0 big-endian filesystem."""
+
+    # Random SquashFS version 3.0 big-endian header found on binwalk GitHub issue tracker.
+    buf = bytes.fromhex(
+        "73717368000000b60000002042010d364200bc844200339440016800000300006b0400104003004ae64f330000000000"
+        "001623000100000000001177ff8e0800000000000e303100000000000e3025000000000000000000000000000e234c00"
+    )
+
+    sb = c_squashfs.squashfs_super_block(buf)
+    assert sb.s_magic == c_squashfs.SQUASHFS_MAGIC_SWAP
+    assert sb.s_major == 0x300
+
+    with pytest.raises(NotImplementedError, match="Unsupported squashfs pre-4.0 big-endian filesystem"):
+        SquashFS(BytesIO(buf))
diff --git a/tox.ini b/tox.ini
@@ -55,12 +55,12 @@ deps =
     sphinx-design
     furo
 commands =
-    make -C tests/docs clean
-    make -C tests/docs html
+    make -C tests/_docs clean
+    make -C tests/_docs html
 
 [testenv:docs-linkcheck]
 allowlist_externals = make
 deps = {[testenv:docs-build]deps}
 commands =
-    make -C tests/docs clean
-    make -C tests/docs linkcheck
+    make -C tests/_docs clean
+    make -C tests/_docs linkcheck
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		tests/_data/** filter=lfs diff=lfs merge=lfs -text