Add fuzzer for compression module

Makefile

@@ -1,4 +1,4 @@
-all : fuzzer-html fuzzer-email fuzzer-httpclient fuzzer-json fuzzer-difflib fuzzer-csv fuzzer-decode fuzzer-ast fuzzer-tarfile fuzzer-tarfile-hypothesis fuzzer-zipfile fuzzer-zipfile-hypothesis fuzzer-re fuzzer-configparser fuzzer-tomllib fuzzer-plistlib fuzzer-xml fuzzer-zoneinfo fuzzer-binascii
+all : fuzzer-html fuzzer-email fuzzer-httpclient fuzzer-json fuzzer-difflib fuzzer-csv fuzzer-decode fuzzer-ast fuzzer-tarfile fuzzer-tarfile-hypothesis fuzzer-zipfile fuzzer-zipfile-hypothesis fuzzer-re fuzzer-configparser fuzzer-tomllib fuzzer-plistlib fuzzer-xml fuzzer-zoneinfo fuzzer-binascii fuzzer-compression
 
 PYTHON_CONFIG_PATH=$(CPYTHON_INSTALL_PATH)/bin/python3-config
 CXXFLAGS += $(shell $(PYTHON_CONFIG_PATH) --cflags)
@@ -43,3 +43,6 @@ fuzzer-zoneinfo:
 
 fuzzer-binascii:
 	clang++ $(CXXFLAGS) $(LIB_FUZZING_ENGINE) -std=c++17 fuzzer.cpp -DPYTHON_HARNESS_PATH="\"binascii.py\"" -ldl $(LDFLAGS) -o fuzzer-binascii
+
+fuzzer-compression:
+	clang++ $(CXXFLAGS) $(LIB_FUZZING_ENGINE) -std=c++17 fuzzer.cpp -DPYTHON_HARNESS_PATH="\"compression.py\"" -ldl $(LDFLAGS) -o fuzzer-compression

compression.py

@@ -0,0 +1,140 @@
+from fuzzeddataprovider import FuzzedDataProvider
+import zlib
+import bz2
+import lzma
+
+WBITS_CHOICES = [-15, 0, 15, 31, 47]
+MAX_DECOMPRESS_LEN = 1024 * 1024  # 1 MiB cap to prevent OOM from small inputs
+
+OP_ZLIB_DECOMPRESS = 0
+OP_ZLIB_COMPRESS = 1
+OP_ZLIB_CHECKSUM = 2
+OP_BZ2_COMPRESS_DECOMPRESS = 3
+OP_LZMA_DECOMPRESS = 4
+OP_LZMA_COMPRESS = 5
+NUM_OPS = 6
+
+
+def op_zlib_decompress(fdp):
+    wbits = fdp.PickValueInList(WBITS_CHOICES)
+    use_zdict = fdp.ConsumeBool()
+    do_flush = fdp.ConsumeBool()
+    do_copy = fdp.ConsumeBool()
+    zdict = b""
+    if use_zdict:
+        zdict_size = fdp.ConsumeIntInRange(1, 32768)
+        zdict = fdp.ConsumeBytes(zdict_size)
+    data = fdp.ConsumeBytes(fdp.remaining_bytes())
+    kwargs = {}
+    if zdict:
+        kwargs["zdict"] = zdict
+    dobj = zlib.decompressobj(wbits, **kwargs)
+    dobj.decompress(data, MAX_DECOMPRESS_LEN)
+    if do_flush:
+        dobj.flush()
+    if do_copy:
+        copy_obj = dobj.copy()
+        copy_obj.decompress(data, MAX_DECOMPRESS_LEN)
+
+
+def op_zlib_compress(fdp):
+    level = fdp.ConsumeIntInRange(0, 9)
+    use_obj = fdp.ConsumeBool()
+    do_copy = fdp.ConsumeBool()
+    n = fdp.ConsumeIntInRange(1, 10000)
+    data = fdp.ConsumeBytes(n)
+    if not data:
+        return
+    if use_obj:
+        cobj = zlib.compressobj(level)
+        cobj.compress(data)
+        if do_copy:
+            copy_obj = cobj.copy()
+            copy_obj.flush()
+        cobj.flush()
+    else:
+        zlib.compress(data, level)
+
+
+def op_zlib_checksum(fdp):
+    use_crc = fdp.ConsumeBool()
+    data = fdp.ConsumeBytes(fdp.remaining_bytes())
+    if use_crc:
+        zlib.crc32(data)
+    else:
+        zlib.adler32(data)
+
+
+def op_bz2(fdp):
+    do_compress = fdp.ConsumeBool()
+    n = (
+        fdp.ConsumeIntInRange(1, min(fdp.remaining_bytes(), 10000))
+        if fdp.remaining_bytes() > 0
+        else 0
+    )
+    if n == 0:
+        return
+    data = fdp.ConsumeBytes(n)
+    if do_compress:
+        bz2.compress(data)
+    else:
+        dobj = bz2.BZ2Decompressor()
+        dobj.decompress(data, MAX_DECOMPRESS_LEN)
+
+
+def op_lzma_decompress(fdp):
+    formats = [lzma.FORMAT_AUTO, lzma.FORMAT_XZ, lzma.FORMAT_ALONE, lzma.FORMAT_RAW]
+    fmt = fdp.PickValueInList(formats)
+    n = (
+        fdp.ConsumeIntInRange(1, min(fdp.remaining_bytes(), 10000))
+        if fdp.remaining_bytes() > 0
+        else 0
+    )
+    if n == 0:
+        return
+    data = fdp.ConsumeBytes(n)
+    kwargs = {"format": fmt, "memlimit": 16 * 1024 * 1024}
+    if fmt == lzma.FORMAT_RAW:
+        kwargs["filters"] = [{"id": lzma.FILTER_LZMA2}]
+        del kwargs["memlimit"]
+    dobj = lzma.LZMADecompressor(**kwargs)
+    dobj.decompress(data, MAX_DECOMPRESS_LEN)
+
+
+def op_lzma_compress(fdp):
+    n = (
+        fdp.ConsumeIntInRange(1, min(fdp.remaining_bytes(), 10000))
+        if fdp.remaining_bytes() > 0
+        else 0
+    )
+    if n == 0:
+        return
+    data = fdp.ConsumeBytes(n)
+    lzma.compress(data)
+
+
+# Fuzzes zlib, bz2, and lzma C modules (Modules/zlibmodule.c,
+# Modules/_bz2module.c, Modules/_lzmamodule.c). Exercises decompression
+# with various wbits/format settings and optional zlib dictionaries,
+# compression at different levels with compressobj/compress, CRC32/Adler32
+# checksums, and BZ2/LZMA decompressor objects with memory limits.
+def FuzzerRunOne(FuzzerInput):
+    if len(FuzzerInput) < 1 or len(FuzzerInput) > 0x100000:
+        return
+    fdp = FuzzedDataProvider(FuzzerInput)
+    op = fdp.ConsumeIntInRange(0, NUM_OPS - 1)
+    try:
+        if op == OP_ZLIB_DECOMPRESS:
+            op_zlib_decompress(fdp)
+        elif op == OP_ZLIB_COMPRESS:
+            op_zlib_compress(fdp)
+        elif op == OP_ZLIB_CHECKSUM:
+            op_zlib_checksum(fdp)
+        elif op == OP_BZ2_COMPRESS_DECOMPRESS:
+            op_bz2(fdp)
+        elif op == OP_LZMA_DECOMPRESS:
+            op_lzma_decompress(fdp)
+        else:
+            op_lzma_compress(fdp)
+    except Exception:
+        pass

fuzz_targets.txt

@@ -1,5 +1,6 @@
 ast ast.py
 binascii binascii.py
+compression compression.py
 configparser configparser.py
 csv csv.py
 decode decode.py