lkml.org 
[lkml]   [2011]   [Feb]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [SECURITY] /proc/$pid/ leaks contents across setuid exec
On Mon, 7 Feb 2011, Kees Cook wrote:

> Sure, I know about O_CLOEXEC, but this is about protecting the
> just-been-execed setuid process from the attacking process that has no
> reason to set O_CLOEXEC.
>
> Something like this needs to be enforced on the kernel side. I.e. these
> file in /proc need to have O_CLOEXEC set in a way that cannot be unset.
>
> > Changing the behavior in the core kernel will break userspace.
>
> I don't think /proc/$pid/* needs to stay open across execs, does it? Or at
> least the non-0444 files should be handled separately.

Actually, this seems like a more general kind of bug in proc rather than a
leaked fd. Each child task should only see its own /proc/[pid] data.



- James
--
James Morris
<jmorris@namei.org>


\
 
 \ /
  Last update: 2011-02-08 04:45    [from the cache]
©2003-2011 Jasper Spaans