Merge "Fix checks for reading and writing FuseMessage." (d619026c) · Commits · e / os / android_system_core

libappfuse/FuseBuffer.cc

+25 −12

Original line number	Diff line number	Diff line
		@@ -34,26 +34,38 @@ static_assert(
		"FuseBuffer must be standard layout union.");

		template <typename T>
		bool FuseMessage<T>::CheckHeaderLength() const {
		bool FuseMessage<T>::CheckPacketSize(size_t size, const char* name) const {
		const auto& header = static_cast<const T*>(this)->header;
		if (sizeof(header) <= header.len && header.len <= sizeof(T)) {
		if (size >= sizeof(header) && size <= sizeof(T)) {
		return true;
		} else {
		LOG(ERROR) << "Packet size is invalid=" << header.len;
		LOG(ERROR) << name << " is invalid=" << size;
		return false;
		}
		}

		template <typename T>
		bool FuseMessage<T>::CheckResult(
		int result, const char* operation_name) const {
		bool FuseMessage<T>::CheckResult(int result, const char* operation_name) const {
		if (result == 0) {
		// Expected close of other endpoints.
		return false;
		}
		if (result < 0) {
		PLOG(ERROR) << "Failed to " << operation_name << " a packet";
		return false;
		}
		return true;
		}

		template <typename T>
		bool FuseMessage<T>::CheckHeaderLength(int result, const char* operation_name) const {
		const auto& header = static_cast<const T*>(this)->header;
		if (result >= 0 && static_cast<uint32_t>(result) == header.len) {
		if (static_cast<uint32_t>(result) == header.len) {
		return true;
		} else {
		PLOG(ERROR) << "Failed to " << operation_name
		<< " a packet. result=" << result << " header.len="
		<< header.len;
		LOG(ERROR) << "Invalid header length: operation_name=" << operation_name
		<< " result=" << result
		<< " header.len=" << header.len;
		return false;
		}
		}
		@@ -61,17 +73,18 @@ bool FuseMessage<T>::CheckResult(
		template <typename T>
		bool FuseMessage<T>::Read(int fd) {
		const ssize_t result = TEMP_FAILURE_RETRY(::read(fd, this, sizeof(T)));
		return CheckHeaderLength() && CheckResult(result, "read");
		return CheckResult(result, "read") && CheckPacketSize(result, "read count") &&
		CheckHeaderLength(result, "read");
		}

		template <typename T>
		bool FuseMessage<T>::Write(int fd) const {
		const auto& header = static_cast<const T*>(this)->header;
		if (!CheckHeaderLength()) {
		if (!CheckPacketSize(header.len, "header.len")) {
		return false;
		}
		const ssize_t result = TEMP_FAILURE_RETRY(::write(fd, this, header.len));
		return CheckResult(result, "write");
		return CheckResult(result, "write") && CheckHeaderLength(result, "write");
		}

		template class FuseMessage<FuseRequest>;

libappfuse/include/libappfuse/FuseBuffer.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -34,8 +34,9 @@ class FuseMessage {
		bool Read(int fd);
		bool Write(int fd) const;
		private:
		bool CheckHeaderLength() const;
		bool CheckPacketSize(size_t size, const char* name) const;
		bool CheckResult(int result, const char* operation_name) const;
		bool CheckHeaderLength(int result, const char* operation_name) const;
		};

		// FuseRequest represents file operation requests from /dev/fuse. It starts