CSE 330 MODULE 8 - INPUT/OUTPUT AND SYSTEM PROTECTION
QUESTIONS WITH ANSWERS AND EXPLANATIONS
Question 1. When evaluating system hardening, which behavior is associated with Access control?
A. Effective access depends on identity, policy, object permissions, and sometimes capabilities or ACLs.
B. ACLs answer which principals may access a given object in which ways.
C. Security depends on controlling creation, transfer, storage, and revocation of capabilities.
D. Privilege should be minimized in scope, time, and accessible resources.
Correct Answer: A. Effective access depends on identity, policy, object permissions, and sometimes
capabilities or ACLs.
Explanation: Effective access depends on identity, policy, object permissions, and sometimes capabilities or ACLs.
Question 2. When evaluating system hardening, how should Polling be characterized?
A. Kernel software that controls a particular class/model of hardware and presents standardized OS interfaces.
B. OS logic providing common naming, protection, buffering, error reporting, and interfaces across many device
drivers.
C. Repeated software checks of device/status state to detect readiness or completion.
D. Queuing complete jobs in secondary storage so a serially shared device can process them one at a time.
Correct Answer: C. Repeated software checks of device/status state to detect readiness or completion.
Explanation: Polling: Repeated software checks of device/status state to detect readiness or completion.
Question 3. In a protection-design review, an implementation needs to protect sensitive computation and
secrets with hardware isolation. What should it use?
A. Access control
B. Security enclave
C. Access control list
D. Capability
Correct Answer: B. Security enclave
Explanation: Security enclave is the best fit because it is used to protect sensitive computation and secrets with
hardware isolation.
Question 4. During an I/O-path review, which definition best describes Programmed I/O?
A. Hardware that manages device-specific control, status, buffering, and protocol details between a device and the
system bus/CPU.
B. An I/O method where the CPU explicitly reads/writes device registers or buffers for each transfer unit.
C. An I/O method where the CPU initiates an operation and the device interrupts when service/completion is
needed.
D. A mechanism allowing a controller to transfer blocks between a device and memory with limited CPU
intervention.
Correct Answer: B. An I/O method where the CPU explicitly reads/writes device registers or buffers for each
transfer unit.
Explanation: Programmed I/O: An I/O method where the CPU explicitly reads/writes device registers or buffers for each
transfer unit.
,Question 5. During an I/O-path review, which property of Principle of least privilege is most important?
A. Effective access depends on identity, policy, object permissions, and sometimes capabilities or ACLs.
B. ACLs answer which principals may access a given object in which ways.
C. Security depends on controlling creation, transfer, storage, and revocation of capabilities.
D. Privilege should be minimized in scope, time, and accessible resources.
Correct Answer: D. Privilege should be minimized in scope, time, and accessible resources.
Explanation: Privilege should be minimized in scope, time, and accessible resources.
Question 6. When evaluating system hardening, which design choice best addresses the requirement to
smooth device/application speed mismatch?
A. I/O controller
B. I/O buffering
C. Programmed I/O
D. Interrupt-driven I/O
Correct Answer: B. I/O buffering
Explanation: I/O buffering is the best fit because it is used to smooth device/application speed mismatch.
Question 7. In a protection-design review, what should an engineer remember about Kernel attack surface?
A. Effective access depends on identity, policy, object permissions, and sometimes capabilities or ACLs.
B. ACLs answer which principals may access a given object in which ways.
C. Security depends on controlling creation, transfer, storage, and revocation of capabilities.
D. Reducing unnecessary privileged code/interfaces can reduce attack opportunities.
Correct Answer: D. Reducing unnecessary privileged code/interfaces can reduce attack opportunities.
Explanation: Reducing unnecessary privileged code/interfaces can reduce attack opportunities.
Question 8. During an I/O-path review, which definition best describes Device-independent I/O layer?
A. Kernel software that controls a particular class/model of hardware and presents standardized OS interfaces.
B. Queuing complete jobs in secondary storage so a serially shared device can process them one at a time.
C. Repeated software checks of device/status state to detect readiness or completion.
D. OS logic providing common naming, protection, buffering, error reporting, and interfaces across many device
drivers.
Correct Answer: D. OS logic providing common naming, protection, buffering, error reporting, and interfaces
across many device drivers.
Explanation: Device-independent I/O layer: OS logic providing common naming, protection, buffering, error reporting,
and interfaces across many device drivers.
Question 9. When evaluating system hardening, which implementation choice would misuse Data execution
prevention?
A. Granting broad write/execute privileges by default and relying on users not to misuse them.
B. Assuming non-executable stacks eliminate every memory-corruption exploit.
C. Leaving obsolete principals on sensitive-object ACLs after roles change.
D. Treating an ordinary guessable integer handle as an unforgeable capability without protection.
Correct Answer: B. Assuming non-executable stacks eliminate every memory-corruption exploit.
Explanation: The key pitfall is: Assuming non-executable stacks eliminate every memory-corruption exploit.
, Question 10. While analyzing device management, which statement about Programmed I/O is correct?
A. Controllers expose registers/queues that device drivers use to issue work and observe completion.
B. Interrupts reduce polling waste but still require handler and scheduling overhead.
C. CPU involvement can be high because software performs the actual data movement.
D. The CPU still sets up DMA and must coordinate buffer ownership/cache visibility/completion.
Correct Answer: C. CPU involvement can be high because software performs the actual data movement.
Explanation: CPU involvement can be high because software performs the actual data movement.
Question 11. When evaluating system hardening, how should Security enclave be characterized?
A. Mechanisms that decide whether a subject such as a user/process may perform an operation on an object such
as a file, process, or device.
B. An object-associated list specifying which users/groups/subjects have particular permissions.
C. A hardware-supported protected execution region designed to isolate code/data from other software, sometimes
including a compromised privileged OS depending on the technology.
D. An unforgeable token/reference that directly grants its holder specified authority to an object.
Correct Answer: C. A hardware-supported protected execution region designed to isolate code/data from other
software, sometimes including a compromised privileged OS depending on the technology.
Explanation: Security enclave: A hardware-supported protected execution region designed to isolate code/data from
other software, sometimes including a compromised privileged OS depending on the technology.
Question 12. While analyzing device management, which mechanism is most appropriate to translate generic
requests into device commands and handle interrupts/errors?
A. Device driver
B. Device-independent I/O layer
C. Spooling
D. Polling
Correct Answer: A. Device driver
Explanation: Device driver is the best fit because it is used to translate generic requests into device commands and
handle interrupts/errors.
Question 13. During an I/O-path review, which misuse of Kernel attack surface should be avoided?
A. Granting broad write/execute privileges by default and relying on users not to misuse them.
B. Leaving obsolete principals on sensitive-object ACLs after roles change.
C. Treating an ordinary guessable integer handle as an unforgeable capability without protection.
D. Loading unnecessary privileged drivers and enabling unused kernel interfaces on exposed systems.
Correct Answer: D. Loading unnecessary privileged drivers and enabling unused kernel interfaces on exposed
systems.
Explanation: The key pitfall is: Loading unnecessary privileged drivers and enabling unused kernel interfaces on exposed
systems.
QUESTIONS WITH ANSWERS AND EXPLANATIONS
Question 1. When evaluating system hardening, which behavior is associated with Access control?
A. Effective access depends on identity, policy, object permissions, and sometimes capabilities or ACLs.
B. ACLs answer which principals may access a given object in which ways.
C. Security depends on controlling creation, transfer, storage, and revocation of capabilities.
D. Privilege should be minimized in scope, time, and accessible resources.
Correct Answer: A. Effective access depends on identity, policy, object permissions, and sometimes
capabilities or ACLs.
Explanation: Effective access depends on identity, policy, object permissions, and sometimes capabilities or ACLs.
Question 2. When evaluating system hardening, how should Polling be characterized?
A. Kernel software that controls a particular class/model of hardware and presents standardized OS interfaces.
B. OS logic providing common naming, protection, buffering, error reporting, and interfaces across many device
drivers.
C. Repeated software checks of device/status state to detect readiness or completion.
D. Queuing complete jobs in secondary storage so a serially shared device can process them one at a time.
Correct Answer: C. Repeated software checks of device/status state to detect readiness or completion.
Explanation: Polling: Repeated software checks of device/status state to detect readiness or completion.
Question 3. In a protection-design review, an implementation needs to protect sensitive computation and
secrets with hardware isolation. What should it use?
A. Access control
B. Security enclave
C. Access control list
D. Capability
Correct Answer: B. Security enclave
Explanation: Security enclave is the best fit because it is used to protect sensitive computation and secrets with
hardware isolation.
Question 4. During an I/O-path review, which definition best describes Programmed I/O?
A. Hardware that manages device-specific control, status, buffering, and protocol details between a device and the
system bus/CPU.
B. An I/O method where the CPU explicitly reads/writes device registers or buffers for each transfer unit.
C. An I/O method where the CPU initiates an operation and the device interrupts when service/completion is
needed.
D. A mechanism allowing a controller to transfer blocks between a device and memory with limited CPU
intervention.
Correct Answer: B. An I/O method where the CPU explicitly reads/writes device registers or buffers for each
transfer unit.
Explanation: Programmed I/O: An I/O method where the CPU explicitly reads/writes device registers or buffers for each
transfer unit.
,Question 5. During an I/O-path review, which property of Principle of least privilege is most important?
A. Effective access depends on identity, policy, object permissions, and sometimes capabilities or ACLs.
B. ACLs answer which principals may access a given object in which ways.
C. Security depends on controlling creation, transfer, storage, and revocation of capabilities.
D. Privilege should be minimized in scope, time, and accessible resources.
Correct Answer: D. Privilege should be minimized in scope, time, and accessible resources.
Explanation: Privilege should be minimized in scope, time, and accessible resources.
Question 6. When evaluating system hardening, which design choice best addresses the requirement to
smooth device/application speed mismatch?
A. I/O controller
B. I/O buffering
C. Programmed I/O
D. Interrupt-driven I/O
Correct Answer: B. I/O buffering
Explanation: I/O buffering is the best fit because it is used to smooth device/application speed mismatch.
Question 7. In a protection-design review, what should an engineer remember about Kernel attack surface?
A. Effective access depends on identity, policy, object permissions, and sometimes capabilities or ACLs.
B. ACLs answer which principals may access a given object in which ways.
C. Security depends on controlling creation, transfer, storage, and revocation of capabilities.
D. Reducing unnecessary privileged code/interfaces can reduce attack opportunities.
Correct Answer: D. Reducing unnecessary privileged code/interfaces can reduce attack opportunities.
Explanation: Reducing unnecessary privileged code/interfaces can reduce attack opportunities.
Question 8. During an I/O-path review, which definition best describes Device-independent I/O layer?
A. Kernel software that controls a particular class/model of hardware and presents standardized OS interfaces.
B. Queuing complete jobs in secondary storage so a serially shared device can process them one at a time.
C. Repeated software checks of device/status state to detect readiness or completion.
D. OS logic providing common naming, protection, buffering, error reporting, and interfaces across many device
drivers.
Correct Answer: D. OS logic providing common naming, protection, buffering, error reporting, and interfaces
across many device drivers.
Explanation: Device-independent I/O layer: OS logic providing common naming, protection, buffering, error reporting,
and interfaces across many device drivers.
Question 9. When evaluating system hardening, which implementation choice would misuse Data execution
prevention?
A. Granting broad write/execute privileges by default and relying on users not to misuse them.
B. Assuming non-executable stacks eliminate every memory-corruption exploit.
C. Leaving obsolete principals on sensitive-object ACLs after roles change.
D. Treating an ordinary guessable integer handle as an unforgeable capability without protection.
Correct Answer: B. Assuming non-executable stacks eliminate every memory-corruption exploit.
Explanation: The key pitfall is: Assuming non-executable stacks eliminate every memory-corruption exploit.
, Question 10. While analyzing device management, which statement about Programmed I/O is correct?
A. Controllers expose registers/queues that device drivers use to issue work and observe completion.
B. Interrupts reduce polling waste but still require handler and scheduling overhead.
C. CPU involvement can be high because software performs the actual data movement.
D. The CPU still sets up DMA and must coordinate buffer ownership/cache visibility/completion.
Correct Answer: C. CPU involvement can be high because software performs the actual data movement.
Explanation: CPU involvement can be high because software performs the actual data movement.
Question 11. When evaluating system hardening, how should Security enclave be characterized?
A. Mechanisms that decide whether a subject such as a user/process may perform an operation on an object such
as a file, process, or device.
B. An object-associated list specifying which users/groups/subjects have particular permissions.
C. A hardware-supported protected execution region designed to isolate code/data from other software, sometimes
including a compromised privileged OS depending on the technology.
D. An unforgeable token/reference that directly grants its holder specified authority to an object.
Correct Answer: C. A hardware-supported protected execution region designed to isolate code/data from other
software, sometimes including a compromised privileged OS depending on the technology.
Explanation: Security enclave: A hardware-supported protected execution region designed to isolate code/data from
other software, sometimes including a compromised privileged OS depending on the technology.
Question 12. While analyzing device management, which mechanism is most appropriate to translate generic
requests into device commands and handle interrupts/errors?
A. Device driver
B. Device-independent I/O layer
C. Spooling
D. Polling
Correct Answer: A. Device driver
Explanation: Device driver is the best fit because it is used to translate generic requests into device commands and
handle interrupts/errors.
Question 13. During an I/O-path review, which misuse of Kernel attack surface should be avoided?
A. Granting broad write/execute privileges by default and relying on users not to misuse them.
B. Leaving obsolete principals on sensitive-object ACLs after roles change.
C. Treating an ordinary guessable integer handle as an unforgeable capability without protection.
D. Loading unnecessary privileged drivers and enabling unused kernel interfaces on exposed systems.
Correct Answer: D. Loading unnecessary privileged drivers and enabling unused kernel interfaces on exposed
systems.
Explanation: The key pitfall is: Loading unnecessary privileged drivers and enabling unused kernel interfaces on exposed
systems.
