Added gcd_fuzzer

src/Compression/fuzzers/CMakeLists.txt

@@ -18,3 +18,6 @@ target_link_libraries (double_delta_decompress_fuzzer PRIVATE dbms ${LIB_FUZZING
 
 clickhouse_add_executable (encrypted_decompress_fuzzer encrypted_decompress_fuzzer.cpp)
 target_link_libraries (encrypted_decompress_fuzzer PRIVATE dbms ${LIB_FUZZING_ENGINE})
+
+clickhouse_add_executable (gcd_decompress_fuzzer gcd_decompress_fuzzer.cpp)
+target_link_libraries (gcd_decompress_fuzzer PRIVATE dbms ${LIB_FUZZING_ENGINE})

src/Compression/fuzzers/gcd_decompress_fuzzer.cpp

@@ -0,0 +1,44 @@
+#include <iostream>
+#include <string>
+
+#include <Compression/ICompressionCodec.h>
+#include <IO/BufferWithOwnMemory.h>
+
+namespace DB
+{
+    CompressionCodecPtr getCompressionCodecGCD(Int8 gcd_bytes_size);
+}
+
+struct AuxiliaryRandomData
+{
+    Int8 gcd_size_bytes;
+    size_t decompressed_size;
+};
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t * data, size_t size)
+try
+{
+    if (size < sizeof(AuxiliaryRandomData))
+        return 0;
+
+    const auto * p = reinterpret_cast<const AuxiliaryRandomData *>(data);
+    auto codec = DB::getCompressionCodecGCD(p->gcd_size_bytes);
+
+    size_t output_buffer_size = p->decompressed_size % 65536;
+    size -= sizeof(AuxiliaryRandomData);
+    data += sizeof(AuxiliaryRandomData) / sizeof(uint8_t);
+
+    // std::string input = std::string(reinterpret_cast<const char*>(data), size);
+    // fmt::print(stderr, "Using input {} of size {}, output size is {}. \n", input, size, output_buffer_size);
+
+    DB::Memory<> memory;
+    memory.resize(output_buffer_size + codec->getAdditionalSizeAtTheEndOfBuffer());
+
+    codec->doDecompressData(reinterpret_cast<const char *>(data), size, memory.data(), output_buffer_size);
+
+    return 0;
+}
+catch (...)
+{
+    return 1;
+}