binder_parcel_fuzzer: support owned Parcels
Some codepaths in Parcel are different when the Parcel
is owned. This allows fillRandomParcel to also sometimes
cause the returned Parcel be a view of a filled out
Parcel. This increases the possible impact and bug
finding abilities of all of our AIDL fuzzers as well.
Ignore-AOSP-First: fuzzing
Bug: 369404061
Test: binder_parcel_fuzzer
Change-Id: Ib19a0cbd74d48e18ba36cff56202541105ef9163
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index e2eea6c..0b7cd81 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -2728,6 +2728,65 @@
return 0;
}
+static void do_nothing_release_func(const uint8_t* data, size_t dataSize,
+ const binder_size_t* objects, size_t objectsCount) {
+ (void)data;
+ (void)dataSize;
+ (void)objects;
+ (void)objectsCount;
+}
+static void delete_data_release_func(const uint8_t* data, size_t dataSize,
+ const binder_size_t* objects, size_t objectsCount) {
+ delete[] data;
+ (void)dataSize;
+ (void)objects;
+ (void)objectsCount;
+}
+
+void Parcel::makeDangerousViewOf(Parcel* p) {
+ if (p->isForRpc()) {
+ // warning: this must match the logic in rpcSetDataReference
+ auto* rf = p->maybeRpcFields();
+ LOG_ALWAYS_FATAL_IF(rf == nullptr);
+ std::vector<std::variant<binder::unique_fd, binder::borrowed_fd>> fds;
+ if (rf->mFds) {
+ fds.reserve(rf->mFds->size());
+ for (const auto& fd : *rf->mFds) {
+ fds.push_back(binder::borrowed_fd(toRawFd(fd)));
+ }
+ }
+ status_t result =
+ rpcSetDataReference(rf->mSession, p->mData, p->mDataSize,
+ rf->mObjectPositions.data(), rf->mObjectPositions.size(),
+ std::move(fds), do_nothing_release_func);
+ LOG_ALWAYS_FATAL_IF(result != OK, "Failed: %s", statusToString(result).c_str());
+ } else {
+#ifdef BINDER_WITH_KERNEL_IPC
+ // warning: this must match the logic in ipcSetDataReference
+ auto* kf = p->maybeKernelFields();
+ LOG_ALWAYS_FATAL_IF(kf == nullptr);
+
+ // Ownership of FDs is passed to the Parcel from kernel binder. This should be refactored
+ // to move this ownership out of Parcel and into release_func. However, today, Parcel
+ // always assums it can own and close FDs today. So, for purposes of testing consistency,
+ // , create new FDs it can own.
+
+ uint8_t* newData = new uint8_t[p->mDataSize]; // deleted by delete_data_release_func
+ memcpy(newData, p->mData, p->mDataSize);
+ for (size_t i = 0; i < kf->mObjectsSize; i++) {
+ flat_binder_object* flat =
+ reinterpret_cast<flat_binder_object*>(newData + kf->mObjects[i]);
+ if (flat->hdr.type == BINDER_TYPE_FD) {
+ flat->handle = fcntl(flat->handle, F_DUPFD_CLOEXEC, 0);
+ }
+ }
+
+ ipcSetDataReference(newData, p->mDataSize, kf->mObjects, kf->mObjectsSize,
+ delete_data_release_func);
+#endif // BINDER_WITH_KERNEL_IPC
+ }
+}
+
void Parcel::ipcSetDataReference(const uint8_t* data, size_t dataSize, const binder_size_t* objects,
size_t objectsCount, release_func relFunc) {
// this code uses 'mOwner == nullptr' to understand whether it owns memory
@@ -2738,6 +2797,7 @@
auto* kernelFields = maybeKernelFields();
LOG_ALWAYS_FATAL_IF(kernelFields == nullptr); // guaranteed by freeData.
+ // must match makeDangerousViewOf
mData = const_cast<uint8_t*>(data);
mDataSize = mDataCapacity = dataSize;
kernelFields->mObjects = const_cast<binder_size_t*>(objects);
@@ -2816,6 +2876,7 @@
auto* rpcFields = maybeRpcFields();
LOG_ALWAYS_FATAL_IF(rpcFields == nullptr); // guaranteed by markForRpc.
+ // must match makeDangerousViewOf
mData = const_cast<uint8_t*>(data);
mDataSize = mDataCapacity = dataSize;
mOwner = relFunc;
diff --git a/libs/binder/include/binder/Parcel.h b/libs/binder/include/binder/Parcel.h
index 42c5ebd..b4efa0a 100644
--- a/libs/binder/include/binder/Parcel.h
+++ b/libs/binder/include/binder/Parcel.h
@@ -649,6 +649,11 @@
LIBBINDER_EXPORTED void print(std::ostream& to, uint32_t flags = 0) const;
+ // This API is to quickly become a view of another Parcel, so that we can also
+ // test 'owner' paths quickly. It's extremely dangerous to use this API in
+ // practice, and you should never ever do it.
+ LIBBINDER_EXPORTED void makeDangerousViewOf(Parcel* p);
+
private:
// Close all file descriptors in the parcel at object positions >= newObjectsSize.
void closeFileDescriptors(size_t newObjectsSize);
@@ -664,7 +669,7 @@
void ipcSetDataReference(const uint8_t* data, size_t dataSize, const binder_size_t* objects,
size_t objectsCount, release_func relFunc);
// Takes ownership even when an error is returned.
- status_t rpcSetDataReference(
+ [[nodiscard]] status_t rpcSetDataReference(
const sp<RpcSession>& session, const uint8_t* data, size_t dataSize,
const uint32_t* objectTable, size_t objectTableSize,
std::vector<std::variant<binder::unique_fd, binder::borrowed_fd>>&& ancillaryFds,
diff --git a/libs/binder/tests/parcel_fuzzer/include_random_parcel/fuzzbinder/random_parcel.h b/libs/binder/tests/parcel_fuzzer/include_random_parcel/fuzzbinder/random_parcel.h
index 2812da7..11fcb06 100644
--- a/libs/binder/tests/parcel_fuzzer/include_random_parcel/fuzzbinder/random_parcel.h
+++ b/libs/binder/tests/parcel_fuzzer/include_random_parcel/fuzzbinder/random_parcel.h
@@ -28,6 +28,9 @@
std::function<void(Parcel* p, FuzzedDataProvider& provider)> writeHeader;
std::vector<sp<IBinder>> extraBinders;
std::vector<binder::unique_fd> extraFds;
+
+ // internal state owned by fillRandomParcel, for Parcel views
+ std::vector<std::unique_ptr<Parcel>> extraParcels;
};
/**
diff --git a/libs/binder/tests/parcel_fuzzer/main.cpp b/libs/binder/tests/parcel_fuzzer/main.cpp
index 192f9d5..d06b2d9 100644
--- a/libs/binder/tests/parcel_fuzzer/main.cpp
+++ b/libs/binder/tests/parcel_fuzzer/main.cpp
@@ -70,7 +70,7 @@
uint32_t code = provider.ConsumeIntegral<uint32_t>();
uint32_t flag = provider.ConsumeIntegral<uint32_t>();
- FUZZ_LOG() << "backend: " << backend;
+ FUZZ_LOG() << "doTransactFuzz backend: " << backend;
RandomParcelOptions options;
@@ -101,7 +101,7 @@
// since we are only using a byte to index
CHECK_LE(reads.size(), 255u) << reads.size();
- FUZZ_LOG() << "backend: " << backend;
+ FUZZ_LOG() << "doReadFuzz backend: " << backend;
FUZZ_LOG() << "input: " << HexString(p.data(), p.dataSize());
FUZZ_LOG() << "instructions: " << HexString(instructions.data(), instructions.size());
@@ -122,10 +122,15 @@
RandomParcelOptions options;
P p;
+ // small amount of initial Parcel data, since fillRandomParcel uses makeDangerousViewOf
+ std::vector<uint8_t> parcelData =
+ provider.ConsumeBytes<uint8_t>(provider.ConsumeIntegralInRange<size_t>(0, 20));
+ fillRandomParcel(&p, FuzzedDataProvider(parcelData.data(), parcelData.size()), &options);
+
// since we are only using a byte to index
CHECK_LE(reads.size() + writes.size(), 255u) << reads.size();
- FUZZ_LOG() << "backend: " << backend;
+ FUZZ_LOG() << "doReadWriteFuzz backend: " << backend;
while (provider.remaining_bytes() > 0) {
uint8_t idx = provider.ConsumeIntegralInRange<uint8_t>(0, reads.size() + writes.size() - 1);
diff --git a/libs/binder/tests/parcel_fuzzer/random_parcel.cpp b/libs/binder/tests/parcel_fuzzer/random_parcel.cpp
index 7c19614..dfd178a 100644
--- a/libs/binder/tests/parcel_fuzzer/random_parcel.cpp
+++ b/libs/binder/tests/parcel_fuzzer/random_parcel.cpp
@@ -17,6 +17,7 @@
#include <fuzzbinder/random_parcel.h>
#include <android-base/logging.h>
+#include <binder/Functional.h>
#include <binder/RpcSession.h>
#include <binder/RpcTransportRaw.h>
#include <fuzzbinder/random_binder.h>
@@ -32,10 +33,29 @@
CHECK(OK == p->write(data.data(), data.size()));
}
-void fillRandomParcel(Parcel* p, FuzzedDataProvider&& provider, RandomParcelOptions* options) {
+void fillRandomParcel(Parcel* outputParcel, FuzzedDataProvider&& provider,
+ RandomParcelOptions* options) {
CHECK_NE(options, nullptr);
- if (provider.ConsumeBool()) {
+ const uint8_t fuzzerParcelOptions = provider.ConsumeIntegral<uint8_t>();
+ const bool resultShouldBeView = fuzzerParcelOptions & 1;
+ const bool resultShouldBeRpc = fuzzerParcelOptions & 2;
+
+ Parcel* p;
+ if (resultShouldBeView) {
+ options->extraParcels.push_back(std::make_unique<Parcel>());
+ // held for duration of test, so that view will be valid
+ p = options->extraParcels[options->extraParcels.size() - 1].get();
+ } else {
+ p = outputParcel; // directly fill out the output Parcel
+ }
+ auto viewify_guard = binder::impl::make_scope_guard([&]() {
+ if (resultShouldBeView) {
+ outputParcel->makeDangerousViewOf(p);
+ }
+ });
+
+ if (resultShouldBeRpc) {
auto session = RpcSession::make(RpcTransportCtxFactoryRaw::make());
CHECK_EQ(OK, session->addNullDebuggingClient());
// Set the protocol version so that we don't crash if the session
diff --git a/libs/binder/tests/parcel_fuzzer/random_parcel_seeds.cpp b/libs/binder/tests/parcel_fuzzer/random_parcel_seeds.cpp
index 0ed8a55..3cb6289 100644
--- a/libs/binder/tests/parcel_fuzzer/random_parcel_seeds.cpp
+++ b/libs/binder/tests/parcel_fuzzer/random_parcel_seeds.cpp
@@ -281,9 +281,9 @@
// This buffer holds the bytes which will be used for fillRandomParcel API
std::vector<uint8_t> fillParcelBuffer;
- // Don't take rpc path
- uint8_t rpcBranch = 0;
- impl::writeReversedBuffer(fillParcelBuffer, rpcBranch);
+ // Use all default options.
+ uint8_t parcelOptions = 0;
+ impl::writeReversedBuffer(fillParcelBuffer, parcelOptions);
// Implicit branch on this path -> options->writeHeader(p, provider)
uint8_t writeHeaderInternal = 0;