Messages in this thread | | | Date | Wed, 18 Mar 2015 14:41:00 +0300 | From | Konstantin Khlebnikov <> | Subject | Re: [PATCH RFC] mm: protect suid binaries against rowhammer with copy-on-read mappings |
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On 18.03.2015 12:57, Kirill A. Shutemov wrote: > On Wed, Mar 18, 2015 at 11:30:40AM +0300, Konstantin Khlebnikov wrote: >> From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> >> >> Each user gets private copy of the code thus nobody will be able to exploit >> pages in the page cache. This works for statically-linked binaries. Shared >> libraries are still vulnerable, but setting suid bit will protect them too. > > Hm. Do we have suid/sgid semantic defiend for non-executables? > > To me we should do this for all file private mappings of the suid process > or don't do it at all.
Yeah, this patch doesn't provide full protection. That's just a proof-of-concept.
> > And what about forked suid process which dropped privilages. We still have > code pages shared.
User can get access to that private copy later but new suid applications will get their own copy at exec. Original page-cache pages are never exposed in pte.
> > I don't think it worth it. The only right way to fix the problem is ECC > memory. >
ECC seems good protection until somebody figure out how to break it too.
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