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What is the difference between a stack overflow and buffer overflow ?
What is the difference between Buffer Overflow and Buffer Overrun?
What is the difference between Buffer Overrun and Stack Overflow?
Please include code examples. I have looked at the terms in Wikipedia, but I am unable to match with programming in C or C++ or Java.
Think of a buffer as just an array. People often use "overflow" and "overrun" interchangeably for any time you try to reference an index beyond the end of the array, and that's fine. Personally, I make a distinction:
A buffer overflow is when you try to put more items in the array than the array can hold. They flow out of the end of the buffer. In other words, it comes from writing.
A buffer overrun is when you are iterating over the buffer and keep reading past the end of the array. Your iterator is running through the buffer and keeps going. In other words, it comes from reading.
A stack overflow is much different. Most modern programming environments are stack-based, where they use a stack data structure to control program flow. Every time you call a function, a new item is placed on the program's call stack. When the function returns, the item is popped from the stack. When the stack is empty, the program stops. The thing is, this stack has a limited size. It is possible to call too many functions at one time and fill up the stack. At this point you have a stack overflow. The most common way to do this is when a function calls itself (recursion).
Bufferoverflow / Bufferoverrun:
void k()
{
BYTE buf[5];
for( int i = 0; i < 10; ++i )
buf[i] = 0xcd;
}
Stackoverflow :
void f()
{
int k = 0;
f();
}
You can have difference between buffer overflow and buffer overrun in C/C++:
Stack overflow is kinda buffer overflow when you fill your entire stack 'memory buffer'.
What is the difference between Buffer Overflow and Buffer Overrun? I would say that Buffer over flow is when you attempt to write beyond the end of a buffer, but you have a check which prevents it. buffer over run is when you actually write beyond the end of the buffer. The first is fail fast, the second is harder to detect.
You cannot overrun a buffer in java as it always has bounds checking and thus produces a BufferOverflowException.
What is the difference between Buffer Overrun and Stack Overflow?
They have nothing to do with one another.
