Add additional 2 binder fuzzers
This CL aims to add an additional set of fuzzers for binder, focusing
on BufferedTextOutput and MemoryDealer.
Test: These fuzzers were tested on a Pixel 3a for a few million
iterations without fuzzer-side crashes.
Signed-off-by: Michael Ensing <michael.ensing@leviathansecurity.com>
Change-Id: If7493ce24c78267459696a706dd67c015cf33080
diff --git a/libs/binder/tests/fuzzers/BufferedTextOutputFuzz.cpp b/libs/binder/tests/fuzzers/BufferedTextOutputFuzz.cpp
new file mode 100644
index 0000000..09cb216
--- /dev/null
+++ b/libs/binder/tests/fuzzers/BufferedTextOutputFuzz.cpp
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <commonFuzzHelpers.h>
+#include <fuzzer/FuzzedDataProvider.h>
+#include <string>
+#include <vector>
+#include "BufferedTextOutput.h"
+
+namespace android {
+
+class FuzzBufferedTextOutput : public BufferedTextOutput {
+public:
+ FuzzBufferedTextOutput(uint32_t flags) : BufferedTextOutput(flags) {}
+ virtual status_t writeLines(const struct iovec& buf, size_t) {
+ size_t len = buf.iov_len;
+ void* tmp_buf = malloc(len);
+
+ if (tmp_buf == NULL) {
+ return status_t();
+ }
+
+ // This will attempt to read data from iov_base to ensure valid params were passed.
+ memcpy(tmp_buf, buf.iov_base, len);
+ free(tmp_buf);
+ return status_t();
+ }
+};
+
+// Fuzzer entry point.
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+ FuzzedDataProvider fdp(data, size);
+ uint32_t flags = fdp.ConsumeIntegral<uint32_t>();
+ size_t push_count = 0;
+ std::shared_ptr<BufferedTextOutput> bTextOutput(new FuzzBufferedTextOutput(flags));
+
+ while (fdp.remaining_bytes() > 0) {
+ fdp.PickValueInArray<std::function<void()>>({
+ [&]() -> void {
+ bTextOutput->pushBundle();
+ push_count++;
+ },
+ [&]() -> void {
+ std::string txt = fdp.ConsumeRandomLengthString(fdp.remaining_bytes());
+ size_t len = fdp.ConsumeIntegralInRange<size_t>(0, txt.length());
+ bTextOutput->print(txt.c_str(), len);
+ },
+ [&]() -> void {
+ if (push_count == 0) return;
+
+ bTextOutput->popBundle();
+ push_count--;
+ },
+ })();
+ }
+
+ return 0;
+}
+} // namespace android