Re: PATCH: proc_do_stop and rpctrace

[Ognyan Kulev]

Marcus Brinkmann wrote:
> On Sat, Aug 09, 2003 at 05:33:29PM -0400, Roland McGrath wrote:
> > The concern I have about this patch per se is proc calling thread_resume on
> > a random port from the user.  This is at least a DoS opportunity.  It also
> > points to a more general problem rpctrace has--servers make comparisons
> > between ports from the user (rpctrace) and ports outside rpctrace's sphere
> > of interposition.  I bet "rpctrace ln foo bar" (dir_link) gets EXDEV too.
>
> Shall I revert the patch?

proc also uses the task port given by rpctrace.  So one can write a 
program that passes fake task port to proc, and when proc tries to 
handle the fake process in some way, the whole proc server will hang 
because it is single-threaded.  Isn't it principally like the 
thread_resume case?

Regards
--
Ognyan Kulev <ogi@{fmi.uni-sofia.bg,fsa-bg.org}>
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