Null pointer dereference

The 1 execve and 2 fexecve system calls in the FreeBSD kernel 8.4 before p11, 9.1 before p14, 9.2 before p7, and 10.0 before p4 destroys the virtual memory address space and mappings for a process before all threads have terminated, which allows local users to cause a denial of service triple-fau...