A problem with either segmented or paged address translation is timing. Suppose a user wants to read some data from an input device into memory. For efficiency during data transfer, often the actual memory address where the data are to be placed is provided to an I/O device. The real address is passed so that time-consuming address translation does not have to be performed during a very fast data transfer. What security problems does this approach bring?

What will be an ideal response?

Address bounding, possibility of a process’s moving while the I/O transfer is going on, possibility of forging an address or modifying it after translation but before its receipt by the I/O device, possibility of translation or transmission failure so that the I/O device receives an incorrect address. With paging, there is also the problem of the amount of data crossing a page boundary.