Null Pointer Dereference
A null pointer dereference accesses a NULL pointer, causing a segmentation fault crash; it can be exploited for denial of service.
Purpose
To understand the crashes and DoS risk caused by null pointer dereference; a common reliability defect.
Mechanism
Dereferencing NULL (address 0) triggers a hardware page fault; the OS sends SIGSEGV to terminate the process. Kernel-mode null dereference can lead to privilege escalation (early Linux). Defenses: pointer checks, null-safe types.
Use cases
- DoS vulnerability analysis
- Reliability audit
- Kernel security