How can I configure my linux system to be secure against DMA-attacks? Is there a way to make them impossible?
excerpt From wikipedia
In modern operating systems, non-system (i.e. user-mode) applications are prevented from accessing any memory locations not explicitly authorized by the virtual memory controller (called the MMU or Memory Mapping Unit). In addition to containing damage from inadvertent software bugs and allowing more efficient use of physical memory, this architecture forms an integral part of the security of a modern operating system. However, kernel-mode drivers, many hardware devices, and occasional user-mode vulnerabilities allow the direct, unimpeded access of the physical memory address space. The physical address space includes all of the main system memory, as well as memory-mapped buses and hardware devices (which are controlled by the operating system through reads and writes as if they were ordinary RAM).