Messages in this thread | | | Date | Fri, 1 Jul 2011 14:12:02 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH v2] kernel: escape non-ASCII and control characters in printk() |
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* Vasiliy Kulikov <segoon@openwall.com> wrote:
> On Mon, Jun 27, 2011 at 00:01 +0200, Ingo Molnar wrote: > > * Vasiliy Kulikov <segoon@openwall.com> wrote: > > > On Sun, Jun 26, 2011 at 21:46 +0200, Ingo Molnar wrote: > > > > No, because the problems such a mistake causes are not equivalent: it > > > > would have been far more harmful to not print out the *very real* > > > > product names written in some non-US language than to accidentally > > > > include some control character you did not think of. > > > > > > ??? > > > > > > Not "not print", but print in "crypted" form. The information > > > is still not lost, you can obviously restore it to the original > > > form, with some effort, but possible. Compare it with the harm > > > of log spoofing - it is not "restorable". > > > > The harm of 'potential' log spoofing affecting exactly zero known > > users right now, > > ??? > > A potential thing affects all users that *can be* affected by > actual log spoofing. This is what the word "potential" means.
Yes, but there's a world of a difference between alleged harm and actual demonstrated harm.
That is a not so fine distinction that is often missed in security circles! :-)
So what i asked for before and what i ask for here is to protect against real, specific harm. If we just 'protect' against things that look dangerous it's easy to over-protect and cause colletaral damage. (like the UTF-8 details the v1 patch missed)
> Analogy: if some privilege escalation bug is found in some very > core code then all users iteracting with an untrusted security > domains (local users, network, etc.) being able to exploit it would > be affected. It is silly to say that nobody is affected because you > just don't know any such cases of this bug exploitation in the > past.
That analogy does not hold. If a security hole is obvious at first sight then we'll indeed fix it without waiting for someone to be exploited.
But here the actual 'harm' is a lot less clear and what i'm trying to steer you towards is to be more fact-based and less belief-based. The only 'harm' that got demonstrated so far was collateral damage caused by the v1 patch ...
Thanks,
Ingo
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