Re: [PATCH] lib/syscall: Clear return values when no stack

2017-03-23 Thread Andy Lutomirski
On Thu, Mar 23, 2017 at 3:46 PM, Kees Cook wrote: > Commit aa1f1a639621 ("lib/syscall: Pin the task stack in collect_syscall()") > added logic to handle a process stack not existing, but left sp and pc > uninitialized, which can be later reported via /proc/$pid/syscall for zombie > processes, pote

[PATCH] lib/syscall: Clear return values when no stack

2017-03-23 Thread Kees Cook
Commit aa1f1a639621 ("lib/syscall: Pin the task stack in collect_syscall()") added logic to handle a process stack not existing, but left sp and pc uninitialized, which can be later reported via /proc/$pid/syscall for zombie processes, potentially exposing kernel memory to userspace. Zombie /proc/