FreeBSD 6.1 - kqueue() Null Pointer Dereference Privilege Escalation

FreeBSD 6.1 - kqueue Null Pointer Dereference Privilege Escalation / FreeBSD include include include include include include include include include include include include int fd, kq; struct kevent kev, ke; struct timespec timeout; volatile int gotroot = 0; static void kernelcodevoid struct thre...

FreeBSD <= 6.1 kqueue() NULL pointer dereference

FreeBSD = 6.1 suffers from classical check/use race condition on SMP systems in kevent syscall, leading to kernel mode NULL pointer dereference. It can be triggered by spawning two threads: 1st thread looping on open and close syscalls, and the 2nd thread looping on kevent, trying to add possibly...