Messages in this thread | | | Date | Tue, 27 Jun 2017 10:00:23 +0200 (CEST) | From | Jiri Kosina <> | Subject | Re: [tip:x86/mm] x86/mmap, ASLR: Do not treat unlimited-stack tasks as legacy mmap |
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On Fri, 23 Jun 2017, Oleg Nesterov 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.
Could you please be a bit more specific here?
mmap_is_legacy() *first* checks for the ADDR_COMPAT_LAYOUT in the personality flags, and only then, if it's unset, RLIMIT_STACK comes to play.
Thanks,
-- Jiri Kosina SUSE Labs
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