[Pvfs2-developers] Possible IO exploit?
dbonnie at parl.clemson.edu
Thu Jun 5 15:02:35 EDT 2008
Hey all -
Nick and I are digging through the permissions checking in various state
machines and we're a little confused about something. It seems that both
the truncate and io state machines do not check permissions unless root
squashing has been performed. If it hasn't, the checks in-place now
simply allow access.
Is there any checking going on somewhere we aren't finding it? Both state
machines use the PINT_SERVER_CHECK_NONE value in the server request
parameters structure which seems to bypass all permissions checking
entirely except for the root squashing case. Right now the client-side
calls do a getattr before doing any io and thus get denied access if
privileges don't match.
It seems like it'd be fairly easy to write a program that could directly
send io requests with any file handle to grab or overwrite data.
Is this something that just got overlooked or is there some kind of check
in place to prevent this?
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