Add block fuzzers

tests/fuzz/Makefile

@@ -50,8 +50,10 @@ default: all
 all: \
 	simple_round_trip \
 	stream_round_trip \
+	block_round_trip \
 	simple_decompress \
-	stream_decompress
+	stream_decompress \
+	block_decompress
 
 %.o: %.c
 	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $^ -c -o $@
@@ -62,12 +64,18 @@ simple_round_trip: $(FUZZ_HEADERS) $(ZSTD_OBJ) simple_round_trip.o
 stream_round_trip: $(FUZZ_HEADERS) $(ZSTD_OBJ) stream_round_trip.o
 	$(CXX) $(FUZZ_TARGET_FLAGS) $(ZSTD_OBJ) stream_round_trip.o $(LIB_FUZZING_ENGINE) -o $@
 
+block_round_trip: $(FUZZ_HEADERS) $(ZSTD_OBJ) block_round_trip.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(ZSTD_OBJ) block_round_trip.o $(LIB_FUZZING_ENGINE) -o $@
+
 simple_decompress: $(FUZZ_HEADERS) $(ZSTD_OBJ) simple_decompress.o
 	$(CXX) $(FUZZ_TARGET_FLAGS) $(ZSTD_OBJ) simple_decompress.o $(LIB_FUZZING_ENGINE) -o $@
 
 stream_decompress: $(FUZZ_HEADERS) $(ZSTD_OBJ) stream_decompress.o
 	$(CXX) $(FUZZ_TARGET_FLAGS) $(ZSTD_OBJ) stream_decompress.o $(LIB_FUZZING_ENGINE) -o $@
 
+block_decompress: $(FUZZ_HEADERS) $(ZSTD_OBJ) block_decompress.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(ZSTD_OBJ) block_decompress.o $(LIB_FUZZING_ENGINE) -o $@
+
 libregression.a: $(FUZZ_HEADERS) $(PRGDIR)/util.h regression_driver.o
 	$(AR) $(FUZZ_ARFLAGS) $@ regression_driver.o
 

tests/fuzz/block_decompress.c

@@ -0,0 +1,51 @@
+/**
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+
+/**
+ * This fuzz target attempts to decompress the fuzzed data with the simple
+ * decompression function to ensure the decompressor never crashes.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+
+static ZSTD_DCtx *dctx = NULL;
+static void* rBuf = NULL;
+static size_t bufSize = 0;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    size_t const neededBufSize = ZSTD_BLOCKSIZE_MAX;
+
+    FUZZ_seed(&src, &size);
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (neededBufSize > bufSize) {
+        free(rBuf);
+        rBuf = malloc(neededBufSize);
+        bufSize = neededBufSize;
+        FUZZ_ASSERT(rBuf);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+    ZSTD_decompressBegin(dctx);
+    ZSTD_decompressBlock(dctx, rBuf, neededBufSize, src, size);
+
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}

tests/fuzz/block_round_trip.c

@@ -0,0 +1,99 @@
+/**
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+
+static const int kMaxClevel = 19;
+
+static ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+static void* cBuf = NULL;
+static void* rBuf = NULL;
+static size_t bufSize = 0;
+static uint32_t seed;
+
+static size_t roundTripTest(void *result, size_t resultCapacity,
+                            void *compressed, size_t compressedCapacity,
+                            const void *src, size_t srcSize)
+{
+  int const cLevel = FUZZ_rand(&seed) % kMaxClevel;
+  size_t ret = ZSTD_compressBegin(cctx, cLevel);
+
+  if (ZSTD_isError(ret)) {
+      fprintf(stderr, "ZSTD_compressBegin() error: %s\n",
+              ZSTD_getErrorName(ret));
+      return ret;
+  }
+
+  ret = ZSTD_compressBlock(cctx, compressed, compressedCapacity, src, srcSize);
+  if (ZSTD_isError(ret)) {
+    fprintf(stderr, "ZSTD_compressBlock() error: %s\n", ZSTD_getErrorName(ret));
+    return ret;
+  }
+  if (ret == 0) {
+        FUZZ_ASSERT(resultCapacity >= srcSize);
+        memcpy(result, src, srcSize);
+        return srcSize;
+  }
+  ZSTD_decompressBegin(dctx);
+  return ZSTD_decompressBlock(dctx, result, resultCapacity, compressed, ret);
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    size_t neededBufSize;
+
+    seed = FUZZ_seed(&src, &size);
+    neededBufSize = size;
+    if (size > ZSTD_BLOCKSIZE_MAX)
+        return 0;
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (neededBufSize > bufSize || !cBuf || !rBuf) {
+        free(cBuf);
+        free(rBuf);
+        cBuf = malloc(neededBufSize);
+        rBuf = malloc(neededBufSize);
+        bufSize = neededBufSize;
+        FUZZ_ASSERT(cBuf && rBuf);
+    }
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const result =
+            roundTripTest(rBuf, neededBufSize, cBuf, neededBufSize, src, size);
+        FUZZ_ASSERT_MSG(!ZSTD_isError(result), ZSTD_getErrorName(result));
+        FUZZ_ASSERT_MSG(result == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!memcmp(src, rBuf, size), "Corruption!");
+    }
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}