What is the difference between stack overflow and heap overflow?
Stack overflows corrupt memory on the stack. This means that values of local variables, function arguments, and return addresses are affected. Whereas heap overflows refer to overflows that corrupt memory located on the heap. Global variables and other program data are affected.
What is stack overflow with example?
The most-common cause of stack overflow is excessively deep or infinite recursion, in which a function calls itself so many times that the space needed to store the variables and information associated with each call is more than can fit on the stack. An example of infinite recursion in C. int foo() { return foo(); }
What is the difference between stack based buffer overflow and heap based buffer overflow?
Buffer overflow usually stands for anytime a memory buffer is accessed beyond it’s bounds whether stack or heap. A stack overflow means the stack has exceed it’s allocated limit and on most machines/OS is running over heap.
Can the stack overflow the heap?
A stack overflow can’t overwrite anything on the heap because the heap comes before the stack. An underflow however would force the stack to overflow, causing the program to crash before anything gets overwritten.
What happens if stack overflows?
Usually, when a stack overflow error occurs, the program crashes and can either freeze or close the program. Any unsaved data or work is lost. The stack overflow error is often caused by an infinite loop or the creation of variables larger than the size of the call stack.
How does heap overflow work?
A heap overflow or heap overrun is a type of buffer overflow that occurs in the heap data area. When this happens, the buffer that is assumed to be freed will be expected to hold two pointers FD and BK in the first 8 bytes of the formerly allocated buffer. BK gets written into FD and can be used to overwrite a pointer.
Why is it called stack overflow?
Thus, naming the site Stack Overflow is a bit of programmer-oriented humor, indicating that this is where programmers can go when their stack has overflowed – or, in other words, when they’re out of ideas and need help.
How do you handle stack overflow?
One method to prevent stack overflow is to track the stack pointer with test and measurement methods. Use timer interrupts that periodically check the location of the stack pointer, record the largest value, and watch that it does not grow beyond that value.