.PHONY: clean
clean: compress_fuzzer_clean decompress_fuzzer_clean
+ $(MAKE) -C $(LZ4DIR) clean
+/**
+ * This fuzz target attempts to compress the fuzzed data with the simple
+ * compression function with an output buffer that may be too small to
+ * ensure that the compressor never crashes.
+ */
+
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
-#include "lz4.h"
+#include <string.h>
-#define CHECK(COND) if (!(COND)) { abort(); }
+#include "fuzz_helpers.h"
+#include "lz4.h"
int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
{
- size_t const compressed_dest_size = LZ4_compressBound(size);
- char *const dest_buffer = (char *)malloc(compressed_dest_size);
+ uint32_t seed = FUZZ_seed(&data, &size);
+ size_t const dstCapacity = FUZZ_rand32(&seed, 0, LZ4_compressBound(size));
+ char* const dst = (char*)malloc(dstCapacity);
+ char* const rt = (char*)malloc(size);
+
+ FUZZ_ASSERT(dst);
+ FUZZ_ASSERT(rt);
- CHECK(dest_buffer != NULL);
+ /* If compression succeeds it must round trip correctly. */
+ {
+ int const dstSize = LZ4_compress_default((const char*)data, dst,
+ size, dstCapacity);
+ if (dstSize > 0) {
+ int const rtSize = LZ4_decompress_safe(dst, rt, dstSize, size);
+ FUZZ_ASSERT_MSG(rtSize == size, "Incorrect regenerated size");
+ FUZZ_ASSERT_MSG(!memcmp(data, rt, size), "Corruption!");
+ }
+ }
- // Allocation succeeded, try compressing the incoming data.
- int result = LZ4_compress_default((const char*)data,
- dest_buffer,
- size,
- compressed_dest_size);
- CHECK(result != 0);
+ if (dstCapacity > 0) {
+ /* Compression succeeds and must round trip correctly. */
+ int compressedSize = size;
+ int const dstSize = LZ4_compress_destSize((const char*)data, dst,
+ &compressedSize, dstCapacity);
+ FUZZ_ASSERT(dstSize > 0);
+ int const rtSize = LZ4_decompress_safe(dst, rt, dstSize, size);
+ FUZZ_ASSERT_MSG(rtSize == compressedSize, "Incorrect regenerated size");
+ FUZZ_ASSERT_MSG(!memcmp(data, rt, compressedSize), "Corruption!");
+ }
- free(dest_buffer);
+ free(dst);
+ free(rt);
- return 0;
+ return 0;
}
+/**
+ * This fuzz target attempts to decompress the fuzzed data with the simple
+ * decompression function to ensure the decompressor never crashes.
+ */
+
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
-#include "lz4.h"
+#include <string.h>
-#define CHECK(COND) if (!(COND)) { abort(); }
+#include "fuzz_helpers.h"
+#include "lz4.h"
int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
{
- // TODO: Size input buffer pseudo-randomly based on seed extracted from input
- size_t const buffer_size = 10 * 1024 * 1024;
- char *const dest_buffer = (char *)malloc(buffer_size);
- CHECK(dest_buffer != NULL);
+ uint32_t seed = FUZZ_seed(&data, &size);
+ size_t const dstCapacity = FUZZ_rand32(&seed, 0, 4 * size);
+ size_t const smallDictSize = size + 1;
+ size_t const largeDictSize = 64 * 1024 - 1;
+ size_t const dictSize = MAX(smallDictSize, largeDictSize);
+ char* const dst = (char*)malloc(dstCapacity);
+ char* const dict = (char*)malloc(dictSize + size);
+ char* const largeDict = dict;
+ char* const dataAfterDict = dict + dictSize;
+ char* const smallDict = dataAfterDict - smallDictSize;
- // Allocation succeeded, try decompressing the incoming data.
- int result = LZ4_decompress_safe((const char*)data,
- dest_buffer,
- size,
- buffer_size);
+ FUZZ_ASSERT(dst);
+ FUZZ_ASSERT(dict);
- // Ignore the result of decompression.
- (void)result;
+ /* Prepare the dictionary. The data doesn't matter for decompression. */
+ memset(dict, 0, dictSize);
+ memcpy(dataAfterDict, data, size);
- free(dest_buffer);
+ /* Decompress using each possible dictionary configuration. */
+ /* No dictionary. */
+ LZ4_decompress_safe_usingDict((char const*)data, dst, size,
+ dstCapacity, NULL, 0);
+ /* Small external dictonary. */
+ LZ4_decompress_safe_usingDict((char const*)data, dst, size,
+ dstCapacity, smallDict, smallDictSize);
+ /* Large external dictionary. */
+ LZ4_decompress_safe_usingDict((char const*)data, dst, size,
+ dstCapacity, largeDict, largeDictSize);
+ /* Small prefix. */
+ LZ4_decompress_safe_usingDict((char const*)dataAfterDict, dst, size,
+ dstCapacity, smallDict, smallDictSize);
+ /* Large prefix. */
+ LZ4_decompress_safe_usingDict((char const*)data, dst, size,
+ dstCapacity, largeDict, largeDictSize);
+ /* Partial decompression. */
+ LZ4_decompress_safe_partial((char const*)data, dst, size,
+ dstCapacity, dstCapacity);
+ free(dst);
+ free(dict);
- return 0;
+ return 0;
}
--- /dev/null
+/**
+ * Fuzz target interface.
+ * Fuzz targets have some common parameters passed as macros during compilation.
+ * Check the documentation for each individual fuzzer for more parameters.
+ *
+ * @param FUZZ_RNG_SEED_SIZE:
+ * The number of bytes of the source to look at when constructing a seed
+ * for the deterministic RNG. These bytes are discarded before passing
+ * the data to lz4 functions. Every fuzzer initializes the RNG exactly
+ * once before doing anything else, even if it is unused.
+ * Default: 4.
+ * @param LZ4_DEBUG:
+ * This is a parameter for the lz4 library. Defining `LZ4_DEBUG=1`
+ * enables assert() statements in the lz4 library. Higher levels enable
+ * logging, so aren't recommended. Defining `LZ4_DEBUG=1` is
+ * recommended.
+ * @param LZ4_FORCE_MEMORY_ACCESS:
+ * This flag controls how the zstd library accesses unaligned memory.
+ * It can be undefined, or 0 through 2. If it is undefined, it selects
+ * the method to use based on the compiler. If testing with UBSAN set
+ * MEM_FORCE_MEMORY_ACCESS=0 to use the standard compliant method.
+ * @param FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+ * This is the canonical flag to enable deterministic builds for fuzzing.
+ * Changes to zstd for fuzzing are gated behind this define.
+ * It is recommended to define this when building zstd for fuzzing.
+ */
+
+#ifndef FUZZ_H
+#define FUZZ_H
+
+#ifndef FUZZ_RNG_SEED_SIZE
+# define FUZZ_RNG_SEED_SIZE 4
+#endif
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
--- /dev/null
+/*
+ * 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).
+ */
+
+/**
+ * Helper functions for fuzzing.
+ */
+
+#ifndef FUZZ_HELPERS_H
+#define FUZZ_HELPERS_H
+
+#include "fuzz.h"
+#include "xxhash.h"
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+
+#define FUZZ_QUOTE_IMPL(str) #str
+#define FUZZ_QUOTE(str) FUZZ_QUOTE_IMPL(str)
+
+/**
+ * Asserts for fuzzing that are always enabled.
+ */
+#define FUZZ_ASSERT_MSG(cond, msg) \
+ ((cond) ? (void)0 \
+ : (fprintf(stderr, "%s: %u: Assertion: `%s' failed. %s\n", __FILE__, \
+ __LINE__, FUZZ_QUOTE(cond), (msg)), \
+ abort()))
+#define FUZZ_ASSERT(cond) FUZZ_ASSERT_MSG((cond), "");
+
+#if defined(__GNUC__)
+#define FUZZ_STATIC static __inline __attribute__((unused))
+#elif defined(__cplusplus) || \
+ (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
+#define FUZZ_STATIC static inline
+#elif defined(_MSC_VER)
+#define FUZZ_STATIC static __inline
+#else
+#define FUZZ_STATIC static
+#endif
+
+/**
+ * Deterministically constructs a seed based on the fuzz input.
+ * Consumes up to the first FUZZ_RNG_SEED_SIZE bytes of the input.
+ */
+FUZZ_STATIC uint32_t FUZZ_seed(uint8_t const **src, size_t* size) {
+ uint8_t const *data = *src;
+ size_t const toHash = MIN(FUZZ_RNG_SEED_SIZE, *size);
+ *size -= toHash;
+ *src += toHash;
+ return XXH32(data, toHash, 0);
+}
+
+#define FUZZ_rotl32(x, r) (((x) << (r)) | ((x) >> (32 - (r))))
+
+FUZZ_STATIC uint32_t FUZZ_rand(uint32_t *state) {
+ static const uint32_t prime1 = 2654435761U;
+ static const uint32_t prime2 = 2246822519U;
+ uint32_t rand32 = *state;
+ rand32 *= prime1;
+ rand32 += prime2;
+ rand32 = FUZZ_rotl32(rand32, 13);
+ *state = rand32;
+ return rand32 >> 5;
+}
+
+/* Returns a random numer in the range [min, max]. */
+FUZZ_STATIC uint32_t FUZZ_rand32(uint32_t *state, uint32_t min, uint32_t max) {
+ uint32_t random = FUZZ_rand(state);
+ return min + (random % (max - min + 1));
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
--- /dev/null
+/**
+ * This fuzz target performs a lz4 round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fuzz_helpers.h"
+#include "lz4.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+ uint32_t seed = FUZZ_seed(&data, &size);
+ size_t const dstCapacity = LZ4_compressBound(size);
+ char* const dst = (char*)malloc(dstCapacity);
+ char* const rt = (char*)malloc(size);
+
+ FUZZ_ASSERT(dst);
+ FUZZ_ASSERT(rt);
+
+ /* Compression must succeed and round trip correctly. */
+ int const dstSize = LZ4_compress_default((const char*)data, dst,
+ size, dstCapacity);
+ FUZZ_ASSERT(dstSize > 0);
+
+ int const rtSize = LZ4_decompress_safe(dst, rt, dstSize, size);
+ FUZZ_ASSERT_MSG(rtSize == size, "Incorrect size");
+ FUZZ_ASSERT_MSG(!memcmp(data, rt, size), "Corruption!");
+
+ /* Partial decompression must succeed. */
+ {
+ size_t const partialCapacity = FUZZ_rand32(&seed, 0, size);
+ char* const partial = (char*)malloc(partialCapacity);
+ FUZZ_ASSERT(partial);
+ int const partialSize = LZ4_decompress_safe_partial(
+ dst, partial, dstSize, partialCapacity, partialCapacity);
+ FUZZ_ASSERT(partialSize >= 0);
+ FUZZ_ASSERT_MSG(partialSize == partialCapacity, "Incorrect size");
+ FUZZ_ASSERT_MSG(!memcmp(data, partial, partialSize), "Corruption!");
+ free(partial);
+ }
+
+ free(dst);
+ free(rt);
+
+ return 0;
+}
#include <stdio.h>
#include <stdlib.h>
-#include "testinput.h"
+#include "fuzz.h"
/**
* Main procedure for standalone fuzzing engine.
+++ /dev/null
-#ifndef TESTINPUT_H_INCLUDED
-#define TESTINPUT_H_INCLUDED
-
-#include <inttypes.h>
-
-#if defined (__cplusplus)
-extern "C" {
-#endif
-
-int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
-
-#if defined(__cplusplus)
-}
-#endif
-#endif
projects / platform / upstream / lz4.git / commitdiff