[fuzz] Add LZ4 frame fuzzers

* Round trip fuzzer
* Compress fuzzer
* Decompress fuzzer

1 files changed, 67 insertions, 0 deletions

diff --git a/ossfuzz/decompress_frame_fuzzer.c b/ossfuzz/decompress_frame_fuzzer.c
new file mode 100644
index 0000000..bda25b0
--- /dev/null
+++ b/ossfuzz/decompress_frame_fuzzer.c
@@ -0,0 +1,67 @@
+/**
+ * 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 <string.h>
+
+#include "fuzz_helpers.h"
+#include "lz4.h"
+#define LZ4F_STATIC_LINKING_ONLY
+#include "lz4frame.h"
+#include "lz4_helpers.h"
+
+static void decompress(LZ4F_dctx* dctx, void* dst, size_t dstCapacity,
+                       const void* src, size_t srcSize,
+                       const void* dict, size_t dictSize,
+                       const LZ4F_decompressOptions_t* opts)
+{
+    LZ4F_resetDecompressionContext(dctx);
+    if (dictSize == 0)
+        LZ4F_decompress(dctx, dst, &dstCapacity, src, &srcSize, opts);
+    else
+        LZ4F_decompress_usingDict(dctx, dst, &dstCapacity, src, &srcSize,
+                                  dict, dictSize, opts);
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+
+    uint32_t seed = FUZZ_seed(&data, &size);
+    size_t const dstCapacity = FUZZ_rand32(&seed, 0, 4 * size);
+    size_t const largeDictSize = 64 * 1024;
+    size_t const dictSize = FUZZ_rand32(&seed, 0, largeDictSize);
+    char* const dst = (char*)malloc(dstCapacity);
+    char* const dict = (char*)malloc(dictSize);
+    LZ4F_decompressOptions_t opts;
+    LZ4F_dctx* dctx;
+    LZ4F_createDecompressionContext(&dctx, LZ4F_VERSION);
+
+    FUZZ_ASSERT(dctx);
+    FUZZ_ASSERT(dst);
+    FUZZ_ASSERT(dict);
+
+    /* Prepare the dictionary. The data doesn't matter for decompression. */
+    memset(dict, 0, dictSize);
+
+
+    /* Decompress using multiple configurations. */
+    memset(&opts, 0, sizeof(opts));
+    opts.stableDst = 0;
+    decompress(dctx, dst, dstCapacity, data, size, NULL, 0, &opts);
+    opts.stableDst = 1;
+    decompress(dctx, dst, dstCapacity, data, size, NULL, 0, &opts);
+    opts.stableDst = 0;
+    decompress(dctx, dst, dstCapacity, data, size, dict, dictSize, &opts);
+    opts.stableDst = 1;
+    decompress(dctx, dst, dstCapacity, data, size, dict, dictSize, &opts);
+
+    LZ4F_freeDecompressionContext(dctx);
+    free(dst);
+    free(dict);
+
+    return 0;
+}