Method and apparatus for protecting memory stacks

US6996677B2 · kind B2 · utility

Assignee

• Nortel Networks Limited · CA

Inventors

• Michael Lee · Pensacola, US
• Lawrence Dobranski · Ottawa, CA

Key dates

• Filing date: Feb 20, 2003
• Grant date: Feb 7, 2006
• Expiry date: May 5, 2024

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F21/52
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

Method and apparatus for protecting processing elements from buffer overflow attacks are provided. The apparatus includes a memory stack for, upon execution of a jump to subroutine, storing a return address in a first location in a stack memory. A second location separate from the stack memory for storing an address of the first location and a third location separate from the stack memory for storing the return address itself are included. A first comparator upon completion of the subroutine, compares the address stored in the second location to the first location in the stack memory and a first interrupt generator provides an interrupt signal if locations are not the same. A second comparator looks at the return address stored in the third location and the return address stored in the first location in the stack memory and has a second interrupt generator for generating an interrupt signal if addresses are not the same. A further method and apparatus for protecting processing elements from buffer overflow attacks includes a memory stack for, upon execution of a jump to subroutine in a first processor, storing a return address in a first location in a stack memory and a second loca…