Re: [tip:x86/mm] x86/mmap, ASLR: Do not treat unlimited-stack tasks as legacy mmap

[Oleg Nesterov]

On 06/23, tip-bot for Michal Hocko wrote:
>
> We added a heuristics to treat applications with RLIMIT_STACK configured
> to unlimited as legacy. This means:

To me this also means a minor security problem. The comment above
PER_CLEAR_ON_SETID says "must be cleared upon setuid or setgid exec",
but if you do "ulimit -s unlimited" before suid exec then
ADDR_COMPAT_LAYOUT set by security checks will be ignored.

> So let's try and remove this assumption - hopefully nothing breaks.

Agreed.

Oleg.