1 files changed, 58 insertions, 0 deletions
diff --git a/ossfuzz/compress_fuzzer.c b/ossfuzz/compress_fuzzer.c
new file mode 100644
index 0000000..edc8aad
--- /dev/null
+++ b/ossfuzz/compress_fuzzer.c
@@ -0,0 +1,58 @@
+/**
+ * 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 <string.h>
+
+#include "fuzz_helpers.h"
+#include "fuzz_data_producer.h"
+#include "lz4.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(data, size);
+    size_t const dstCapacitySeed = FUZZ_dataProducer_retrieve32(producer);
+    size = FUZZ_dataProducer_remainingBytes(producer);
+
+    size_t const compressBound = LZ4_compressBound(size);
+    size_t const dstCapacity = FUZZ_getRange_from_uint32(dstCapacitySeed, 0, compressBound);
+
+    char* const dst = (char*)malloc(dstCapacity);
+    char* const rt = (char*)malloc(size);
+
+    FUZZ_ASSERT(dst);
+    FUZZ_ASSERT(rt);
+
+    /* 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!");
+        }
+    }
+
+    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(dst);
+    free(rt);
+    FUZZ_dataProducer_free(producer);
+
+    return 0;
+}