Adds fuzzers for libmediautils

This change adds fuzzers for a few classes in libmediautils.

Test: Ran on Pixel 3a device for a short period. Estimated coverage is 2.94%.
Signed-off-by: Dylan Katz <dylan.katz@leviathansecurity.com>
Change-Id: I147122092659206800d92c4ebd373f692ea1bdb3
diff --git a/media/utils/fuzzers/Android.bp b/media/utils/fuzzers/Android.bp
new file mode 100644
index 0000000..ca1123c
--- /dev/null
+++ b/media/utils/fuzzers/Android.bp
@@ -0,0 +1,51 @@
+cc_defaults {
+    name: "libmediautils_fuzzer_defaults",
+    shared_libs: [
+        "libbinder",
+        "libcutils",
+        "liblog",
+        "libmediautils",
+        "libutils",
+    ],
+
+    cflags: [
+        "-Wall",
+        "-Wextra",
+        "-Werror",
+        "-Wno-c++2a-extensions",
+    ],
+
+    header_libs: [
+        "bionic_libc_platform_headers",
+        "libmedia_headers",
+    ],
+
+    include_dirs: [
+        // For DEBUGGER_SIGNAL
+        "system/core/debuggerd/include",
+    ],
+}
+
+cc_fuzz {
+    name: "libmediautils_fuzzer_battery_notifier",
+    defaults: ["libmediautils_fuzzer_defaults"],
+    srcs: ["BatteryNotifierFuzz.cpp"],
+}
+
+cc_fuzz {
+    name: "libmediautils_fuzzer_scheduling_policy_service",
+    defaults: ["libmediautils_fuzzer_defaults"],
+    srcs: ["SchedulingPolicyServiceFuzz.cpp"],
+}
+
+cc_fuzz {
+    name: "libmediautils_fuzzer_service_utilities",
+    defaults: ["libmediautils_fuzzer_defaults"],
+    srcs: ["ServiceUtilitiesFuzz.cpp"],
+}
+
+cc_fuzz {
+    name: "libmediautils_fuzzer_time_check",
+    defaults: ["libmediautils_fuzzer_defaults"],
+    srcs: ["TimeCheckFuzz.cpp"],
+}
diff --git a/media/utils/fuzzers/BatteryNotifierFuzz.cpp b/media/utils/fuzzers/BatteryNotifierFuzz.cpp
new file mode 100644
index 0000000..00b3cce
--- /dev/null
+++ b/media/utils/fuzzers/BatteryNotifierFuzz.cpp
@@ -0,0 +1,90 @@
+/*
+ * Copyright 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 <functional>
+#include <string>
+#include <vector>
+
+#include <utils/String8.h>
+
+#include "fuzzer/FuzzedDataProvider.h"
+#include "mediautils/BatteryNotifier.h"
+
+static constexpr int kMaxOperations = 30;
+static constexpr int kMaxStringLength = 500;
+using android::BatteryNotifier;
+
+std::vector<std::function<void(std::string /*flashlight_name*/, std::string /*camera_name*/,
+                               uid_t /*video_id*/, uid_t /*audio_id*/, uid_t /*light_id*/,
+                               uid_t /*camera_id*/)>>
+    operations = {
+        [](std::string, std::string, uid_t, uid_t, uid_t, uid_t) -> void {
+            BatteryNotifier::getInstance().noteResetVideo();
+        },
+        [](std::string, std::string, uid_t, uid_t, uid_t, uid_t) -> void {
+            BatteryNotifier::getInstance().noteResetAudio();
+        },
+        [](std::string, std::string, uid_t, uid_t, uid_t, uid_t) -> void {
+            BatteryNotifier::getInstance().noteResetFlashlight();
+        },
+        [](std::string, std::string, uid_t, uid_t, uid_t, uid_t) -> void {
+            BatteryNotifier::getInstance().noteResetCamera();
+        },
+        [](std::string, std::string, uid_t video_id, uid_t, uid_t, uid_t) -> void {
+            BatteryNotifier::getInstance().noteStartVideo(video_id);
+        },
+        [](std::string, std::string, uid_t video_id, uid_t, uid_t, uid_t) -> void {
+            BatteryNotifier::getInstance().noteStopVideo(video_id);
+        },
+        [](std::string, std::string, uid_t, uid_t audio_id, uid_t, uid_t) -> void {
+            BatteryNotifier::getInstance().noteStartAudio(audio_id);
+        },
+        [](std::string, std::string, uid_t, uid_t audio_id, uid_t, uid_t) -> void {
+            BatteryNotifier::getInstance().noteStopAudio(audio_id);
+        },
+        [](std::string flashlight_name, std::string, uid_t, uid_t, uid_t light_id, uid_t) -> void {
+            android::String8 name(flashlight_name.c_str());
+            BatteryNotifier::getInstance().noteFlashlightOn(name, light_id);
+        },
+        [](std::string flashlight_name, std::string, uid_t, uid_t, uid_t light_id, uid_t) -> void {
+            android::String8 name(flashlight_name.c_str());
+            BatteryNotifier::getInstance().noteFlashlightOff(name, light_id);
+        },
+        [](std::string, std::string camera_name, uid_t, uid_t, uid_t, uid_t camera_id) -> void {
+            android::String8 name(camera_name.c_str());
+            BatteryNotifier::getInstance().noteStartCamera(name, camera_id);
+        },
+        [](std::string, std::string camera_name, uid_t, uid_t, uid_t, uid_t camera_id) -> void {
+            android::String8 name(camera_name.c_str());
+            BatteryNotifier::getInstance().noteStopCamera(name, camera_id);
+        },
+};
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    FuzzedDataProvider data_provider(data, size);
+    std::string camera_name = data_provider.ConsumeRandomLengthString(kMaxStringLength);
+    std::string flashlight_name = data_provider.ConsumeRandomLengthString(kMaxStringLength);
+    uid_t video_id = data_provider.ConsumeIntegral<uid_t>();
+    uid_t audio_id = data_provider.ConsumeIntegral<uid_t>();
+    uid_t light_id = data_provider.ConsumeIntegral<uid_t>();
+    uid_t camera_id = data_provider.ConsumeIntegral<uid_t>();
+    size_t ops_run = 0;
+    while (data_provider.remaining_bytes() > 0 && ops_run++ < kMaxOperations) {
+        uint8_t op = data_provider.ConsumeIntegralInRange<uint8_t>(0, operations.size() - 1);
+        operations[op](flashlight_name, camera_name, video_id, audio_id, light_id, camera_id);
+    }
+    return 0;
+}
diff --git a/media/utils/fuzzers/SchedulingPolicyServiceFuzz.cpp b/media/utils/fuzzers/SchedulingPolicyServiceFuzz.cpp
new file mode 100644
index 0000000..4521853
--- /dev/null
+++ b/media/utils/fuzzers/SchedulingPolicyServiceFuzz.cpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright 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.
+ */
+#define LOG_TAG "BatteryNotifierFuzzer"
+#include <binder/IBatteryStats.h>
+#include <binder/IServiceManager.h>
+#include <utils/String16.h>
+#include <android/log.h>
+#include <mediautils/SchedulingPolicyService.h>
+#include "fuzzer/FuzzedDataProvider.h"
+using android::IBatteryStats;
+using android::IBinder;
+using android::IInterface;
+using android::IServiceManager;
+using android::sp;
+using android::String16;
+using android::defaultServiceManager;
+using android::requestCpusetBoost;
+using android::requestPriority;
+sp<IBatteryStats> getBatteryService() {
+    sp<IBatteryStats> batteryStatService;
+    const sp<IServiceManager> sm(defaultServiceManager());
+    if (sm != nullptr) {
+        const String16 name("batterystats");
+        batteryStatService = checked_interface_cast<IBatteryStats>(sm->checkService(name));
+        if (batteryStatService == nullptr) {
+            ALOGW("batterystats service unavailable!");
+            return nullptr;
+        }
+    }
+    return batteryStatService;
+}
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    FuzzedDataProvider data_provider(data, size);
+    sp<IBatteryStats> batteryStatService = getBatteryService();
+    // There is some state here, but it's mostly focused around thread-safety, so
+    // we won't worry about order.
+    int32_t priority = data_provider.ConsumeIntegral<int32_t>();
+    bool is_for_app = data_provider.ConsumeBool();
+    bool async = data_provider.ConsumeBool();
+    requestPriority(getpid(), gettid(), priority, is_for_app, async);
+    // TODO: Verify and re-enable in AOSP (R).
+    // bool enable = data_provider.ConsumeBool();
+    // We are just using batterystats to avoid the need
+    // to register a new service.
+    // requestCpusetBoost(enable, IInterface::asBinder(batteryStatService));
+    return 0;
+}
+
diff --git a/media/utils/fuzzers/ServiceUtilitiesFuzz.cpp b/media/utils/fuzzers/ServiceUtilitiesFuzz.cpp
new file mode 100644
index 0000000..3d141b5
--- /dev/null
+++ b/media/utils/fuzzers/ServiceUtilitiesFuzz.cpp
@@ -0,0 +1,78 @@
+/*
+ * Copyright 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 <fcntl.h>
+
+#include <functional>
+
+#include "fuzzer/FuzzedDataProvider.h"
+#include "mediautils/ServiceUtilities.h"
+
+static constexpr int kMaxOperations = 50;
+static constexpr int kMaxStringLen = 256;
+
+const std::vector<std::function<void(FuzzedDataProvider*, android::MediaPackageManager)>>
+    operations = {
+        [](FuzzedDataProvider* data_provider, android::MediaPackageManager pm) -> void {
+            uid_t uid = data_provider->ConsumeIntegral<uid_t>();
+            pm.allowPlaybackCapture(uid);
+        },
+        [](FuzzedDataProvider* data_provider, android::MediaPackageManager pm) -> void {
+            int spaces = data_provider->ConsumeIntegral<int>();
+
+            // Dump everything into /dev/null
+            int fd = open("/dev/null", O_WRONLY);
+            pm.dump(fd, spaces);
+            close(fd);
+        },
+};
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    FuzzedDataProvider data_provider(data, size);
+    uid_t uid = data_provider.ConsumeIntegral<uid_t>();
+    pid_t pid = data_provider.ConsumeIntegral<pid_t>();
+
+    // There is not state here, and order is not significant,
+    // so we can simply call all of the target functions
+    android::isServiceUid(uid);
+    android::isAudioServerUid(uid);
+    android::isAudioServerOrSystemServerUid(uid);
+    android::isAudioServerOrMediaServerUid(uid);
+    std::string packageNameStr = data_provider.ConsumeRandomLengthString(kMaxStringLen);
+    android::String16 opPackageName(packageNameStr.c_str());
+    android::recordingAllowed(opPackageName, pid, uid);
+    android::startRecording(opPackageName, pid, uid);
+    android::finishRecording(opPackageName, uid);
+    android::captureAudioOutputAllowed(pid, uid);
+    android::captureMediaOutputAllowed(pid, uid);
+    android::captureHotwordAllowed(opPackageName, pid, uid);
+    android::modifyPhoneStateAllowed(uid, pid);
+    android::bypassInterruptionPolicyAllowed(uid, pid);
+    android::settingsAllowed();
+    android::modifyAudioRoutingAllowed();
+    android::modifyDefaultAudioEffectsAllowed();
+    android::dumpAllowed();
+
+    // MediaPackageManager does have state, so we need the fuzzer to decide order
+    android::MediaPackageManager packageManager;
+    size_t ops_run = 0;
+    while (data_provider.remaining_bytes() > 0 && ops_run++ < kMaxOperations) {
+        uint8_t op = data_provider.ConsumeIntegralInRange<uint8_t>(0, operations.size() - 1);
+        operations[op](&data_provider, packageManager);
+    }
+
+    return 0;
+}
diff --git a/media/utils/fuzzers/TimeCheckFuzz.cpp b/media/utils/fuzzers/TimeCheckFuzz.cpp
new file mode 100644
index 0000000..eeb6ba6
--- /dev/null
+++ b/media/utils/fuzzers/TimeCheckFuzz.cpp
@@ -0,0 +1,64 @@
+/*
+ * Copyright 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 <chrono>
+#include <thread>
+
+#include "fuzzer/FuzzedDataProvider.h"
+#include "mediautils/TimeCheck.h"
+
+static constexpr int kMaxStringLen = 256;
+
+// While it might be interesting to test long-running
+// jobs, it seems unlikely it'd lead to the types of crashes
+// we're looking for, and would mean a significant increase in fuzzer time.
+// Therefore, we are setting a low cap.
+static constexpr uint32_t kMaxTimeoutMs = 1000;
+static constexpr uint32_t kMinTimeoutMs = 200;
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    FuzzedDataProvider data_provider(data, size);
+
+    // There's essentially 5 operations that we can access in this class
+    // 1. The time it takes to run this operation. As mentioned above,
+    //    long-running tasks are not good for fuzzing, but there will be
+    //    some change in the run time.
+    uint32_t timeoutMs =
+        data_provider.ConsumeIntegralInRange<uint32_t>(kMinTimeoutMs, kMaxTimeoutMs);
+    uint8_t pid_size = data_provider.ConsumeIntegral<uint8_t>();
+    std::vector<pid_t> pids(pid_size);
+    for (auto& pid : pids) {
+        pid = data_provider.ConsumeIntegral<pid_t>();
+    }
+
+    // 2. We also have setAudioHalPids, which is populated with the pids set
+    // above.
+    android::TimeCheck::setAudioHalPids(pids);
+    std::string name = data_provider.ConsumeRandomLengthString(kMaxStringLen);
+
+    // 3. The constructor, which is fuzzed here:
+    android::TimeCheck timeCheck(name.c_str(), timeoutMs);
+    // We will leave some buffer to avoid sleeping too long
+    uint8_t sleep_amount_ms = data_provider.ConsumeIntegralInRange<uint8_t>(0, timeoutMs / 2);
+
+    // We want to make sure we can cover the time out functionality.
+    if (sleep_amount_ms) {
+        auto ms = std::chrono::milliseconds(sleep_amount_ms);
+        std::this_thread::sleep_for(ms);
+    }
+
+    // 4. Finally, the destructor on timecheck. These seem to be the only factors
+    // in play.
+    return 0;
+}