Question

What are the common causes of the segmentation fault in C?

Answer 1

There are many reasons for the segmentation fault, here I am listing some common causes of the segmentation fault.

• Dereferencing NULL pointers.
• Tried to write read-only memory (such as code segment).
• Trying to access a nonexistent memory address (outside process’s address space).
• Trying to access memory the program does not have rights to (such as kernel structures in process context).
• Sometimes dereferencing or assigning to an uninitialized pointer (because might point an invalid memory) can be the cause of the segmentation fault.
• Dereferencing the freed memory (after calling the free function) can also be caused by the segmentation fault.
• A stack overflow is also caused by the segmentation fault.
• A buffer overflow (try to access the array beyond the boundary) is also a cause of the segmentation fault.