diff options
-rw-r--r-- | libs/binder/RpcServer.cpp | 46 | ||||
-rw-r--r-- | libs/binder/include/binder/RpcServer.h | 7 | ||||
-rw-r--r-- | libs/binder/tests/rpc_fuzzer/Android.bp | 40 | ||||
-rw-r--r-- | libs/binder/tests/rpc_fuzzer/main.cpp | 121 |
4 files changed, 195 insertions, 19 deletions
diff --git a/libs/binder/RpcServer.cpp b/libs/binder/RpcServer.cpp index 06c3a4206d..99c907a021 100644 --- a/libs/binder/RpcServer.cpp +++ b/libs/binder/RpcServer.cpp @@ -118,30 +118,33 @@ sp<IBinder> RpcServer::getRootObject() { } void RpcServer::join() { + while (true) { + (void)acceptOne(); + } +} + +bool RpcServer::acceptOne() { LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!"); + LOG_ALWAYS_FATAL_IF(mServer.get() == -1, "RpcServer must be setup to join."); + + unique_fd clientFd( + TEMP_FAILURE_RETRY(accept4(mServer.get(), nullptr, nullptr /*length*/, SOCK_CLOEXEC))); + + if (clientFd < 0) { + ALOGE("Could not accept4 socket: %s", strerror(errno)); + return false; + } + LOG_RPC_DETAIL("accept4 on fd %d yields fd %d", mServer.get(), clientFd.get()); + { std::lock_guard<std::mutex> _l(mLock); - LOG_ALWAYS_FATAL_IF(mServer.get() == -1, "RpcServer must be setup to join."); + std::thread thread = + std::thread(&RpcServer::establishConnection, this, + std::move(sp<RpcServer>::fromExisting(this)), std::move(clientFd)); + mConnectingThreads[thread.get_id()] = std::move(thread); } - while (true) { - unique_fd clientFd(TEMP_FAILURE_RETRY( - accept4(mServer.get(), nullptr, nullptr /*length*/, SOCK_CLOEXEC))); - - if (clientFd < 0) { - ALOGE("Could not accept4 socket: %s", strerror(errno)); - continue; - } - LOG_RPC_DETAIL("accept4 on fd %d yields fd %d", mServer.get(), clientFd.get()); - - { - std::lock_guard<std::mutex> _l(mLock); - std::thread thread = - std::thread(&RpcServer::establishConnection, this, - std::move(sp<RpcServer>::fromExisting(this)), std::move(clientFd)); - mConnectingThreads[thread.get_id()] = std::move(thread); - } - } + return true; } std::vector<sp<RpcSession>> RpcServer::listSessions() { @@ -154,6 +157,11 @@ std::vector<sp<RpcSession>> RpcServer::listSessions() { return sessions; } +size_t RpcServer::numUninitializedSessions() { + std::lock_guard<std::mutex> _l(mLock); + return mConnectingThreads.size(); +} + void RpcServer::establishConnection(sp<RpcServer>&& server, base::unique_fd clientFd) { LOG_ALWAYS_FATAL_IF(this != server.get(), "Must pass same ownership object"); diff --git a/libs/binder/include/binder/RpcServer.h b/libs/binder/include/binder/RpcServer.h index b1e5519cff..ec741a8b85 100644 --- a/libs/binder/include/binder/RpcServer.h +++ b/libs/binder/include/binder/RpcServer.h @@ -102,9 +102,16 @@ public: void join(); /** + * Accept one connection on this server. You must have at least one client + * session before calling this. + */ + [[nodiscard]] bool acceptOne(); + + /** * For debugging! */ std::vector<sp<RpcSession>> listSessions(); + size_t numUninitializedSessions(); ~RpcServer(); diff --git a/libs/binder/tests/rpc_fuzzer/Android.bp b/libs/binder/tests/rpc_fuzzer/Android.bp new file mode 100644 index 0000000000..1c75306398 --- /dev/null +++ b/libs/binder/tests/rpc_fuzzer/Android.bp @@ -0,0 +1,40 @@ +package { + // See: http://go/android-license-faq + // A large-scale-change added 'default_applicable_licenses' to import + // all of the 'license_kinds' from "frameworks_native_license" + // to get the below license kinds: + // SPDX-license-identifier-Apache-2.0 + default_applicable_licenses: ["frameworks_native_license"], +} + +cc_fuzz { + name: "binder_rpc_fuzzer", + host_supported: true, + + fuzz_config: { + cc: ["smoreland@google.com"], + }, + + srcs: [ + "main.cpp", + ], + static_libs: [ + "libbase", + "libcutils", + "liblog", + "libutils", + ], + + target: { + android: { + shared_libs: [ + "libbinder", + ], + }, + host: { + static_libs: [ + "libbinder", + ], + }, + }, +} diff --git a/libs/binder/tests/rpc_fuzzer/main.cpp b/libs/binder/tests/rpc_fuzzer/main.cpp new file mode 100644 index 0000000000..3603ebe41b --- /dev/null +++ b/libs/binder/tests/rpc_fuzzer/main.cpp @@ -0,0 +1,121 @@ +/* + * Copyright (C) 2021 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 <android-base/file.h> +#include <android-base/logging.h> +#include <android-base/unique_fd.h> +#include <binder/Binder.h> +#include <binder/Parcel.h> +#include <binder/RpcServer.h> +#include <binder/RpcSession.h> + +#include <sys/resource.h> +#include <sys/un.h> + +namespace android { + +static const std::string kSock = std::string(getenv("TMPDIR") ?: "/tmp") + + "/binderRpcFuzzerSocket_" + std::to_string(getpid()); + +size_t getHardMemoryLimit() { + struct rlimit limit; + CHECK(0 == getrlimit(RLIMIT_AS, &limit)) << errno; + return limit.rlim_max; +} + +void setMemoryLimit(size_t cur, size_t max) { + const struct rlimit kLimit = { + .rlim_cur = cur, + .rlim_max = max, + }; + CHECK(0 == setrlimit(RLIMIT_AS, &kLimit)) << errno; +} + +class SomeBinder : public BBinder { + status_t onTransact(uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags = 0) { + (void)flags; + + if ((code & 1) == 0) { + sp<IBinder> binder; + (void)data.readStrongBinder(&binder); + if (binder != nullptr) { + (void)binder->pingBinder(); + } + } + if ((code & 2) == 0) { + (void)data.readInt32(); + } + if ((code & 4) == 0) { + (void)reply->writeStrongBinder(sp<BBinder>::make()); + } + + return OK; + } +}; + +extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) { + if (size > 50000) return 0; + + unlink(kSock.c_str()); + + sp<RpcServer> server = RpcServer::make(); + server->setRootObject(sp<SomeBinder>::make()); + server->iUnderstandThisCodeIsExperimentalAndIWillNotUseItInProduction(); + CHECK(server->setupUnixDomainServer(kSock.c_str())); + + static constexpr size_t kMemLimit = 1llu * 1024 * 1024 * 1024; + size_t hardLimit = getHardMemoryLimit(); + setMemoryLimit(std::min(kMemLimit, hardLimit), hardLimit); + + std::thread serverThread([=] { (void)server->acceptOne(); }); + + sockaddr_un addr{ + .sun_family = AF_UNIX, + }; + CHECK_LT(kSock.size(), sizeof(addr.sun_path)); + memcpy(&addr.sun_path, kSock.c_str(), kSock.size()); + + base::unique_fd clientFd(TEMP_FAILURE_RETRY(socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0))); + CHECK_NE(clientFd.get(), -1); + CHECK_EQ(0, + TEMP_FAILURE_RETRY( + connect(clientFd.get(), reinterpret_cast<sockaddr*>(&addr), sizeof(addr)))) + << strerror(errno); + + serverThread.join(); + + // TODO(b/182938024): fuzz multiple sessions, instead of just one + +#if 0 + // make fuzzer more productive locally by forcing it to create a new session + int32_t id = -1; + CHECK(base::WriteFully(clientFd, &id, sizeof(id))); +#endif + + CHECK(base::WriteFully(clientFd, data, size)); + + clientFd.reset(); + + // TODO(b/185167543): better way to force a server to shutdown + while (!server->listSessions().empty() && server->numUninitializedSessions()) { + usleep(1); + } + + setMemoryLimit(hardLimit, hardLimit); + + return 0; +} + +} // namespace android |