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Date: Wed, 18 Oct 2017 11:28:58 -0400
From: "Theodore Ts'o" <tytso@mit.edu>
To: "Tobin C. Harding" <me@tobin.cc>
Cc: Kees Cook <keescook@chromium.org>,
        Steven Rostedt <rostedt@goodmis.org>,
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Subject: Re: [kernel-hardening] Re: [PATCH v2] printk: hash addresses printed
 with %p
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On Wed, Oct 18, 2017 at 01:28:05PM +1100, Tobin C. Harding wrote:
> > >> Does %p[FfSs] leak addresses? Well, I guess it does if they are not
> > >> found in kallsyms, but otherwise you have:
> > >>
> > >>   function+0x<offset>
> > >
> > 
> > They haven't traditionally been a big deal. If they turn out to be
> > problematic, we can deal with it then, IMO.

If it's not in kallsyms, the raw address is probably not going to be
terribly useful --- so even if it's not traditionally been a big deal,
why not just hash them if it's not going to be printed as "function+0x<offset>"?

If nothing else, it will help correlate the random address with other
places where it was printed via %p.

					- Ted