What is a stack smashing error?
Stack smashing is a form of vulnerability where the stack of a computer application or OS is forced to overflow. This may lead to subverting the program/system and crashing it. A stack, a first-in last-out circuit, is a form of buffer holding intermediate results of operations within it.
What is a stack overflow attack?
In software, a stack buffer overflow or stack buffer overrun occurs when a program writes to a memory address on the program’s call stack outside of the intended data structure, which is usually a fixed-length buffer. A stack buffer overflow can be caused deliberately as part of an attack known as stack smashing.
How does stack smashing protect against Stack Overflow?
The fundamental assumption behind the approach is that most stack buffer overflows occur by writing past the end of a function’s stack frame. In order to detect this case, a “canary value” is added to the stack before other values are declared. Before returning from the function, the stored canary value in the stack is checked.
Why do I get stack smashing message after execution?
After execution the program runs for some time then exits with the message: What could be the possible reasons for this and how do I rectify it? Stack Smashing here is actually caused due to a protection mechanism used by gcc to detect buffer overflow errors. For example in the following snippet:
What causes stack smashing in the GCC compiler?
Stack Smashing here is actually caused due to a protection mechanism used by gcc to detect buffer overflow errors. For example in the following snippet: The compiler, (in this case gcc) adds protection variables (called canaries) which have known values.
How does Stack Smashing Protector ( SSP ) compiler work?
The Stack Smashing Protector(SSP) compiler feature helps detect stack buffer overrun by aborting if a secret value on the stack is changed. This serves a dual purpose in making the occurrence of such bugs visible and as exploit mitigation against return-oriented programming. SSP merely detects stack buffer overruns, they are not prevented.