> Owners are stored in i-nodes. Directory entries are nothing but
> (filename, i-node number) pairs.
>
> link("publicly-visible-file", "world-writable-directory/blah")
> is as anonymous as
> write(open("/world-writable-file", O_WRONLY), "blah", 4)
True. However, one might argue that the former should fail with
EPERM, unless you happen to own "publicly-visible-file". In fact,
I thought I saw a patch go through here a while back that did exactly
that, if "world-writable-directory" was also sticky.
In general, publicly-writable directories are a bad thing. They are
the cause (or at least part of the cause) of numerous vulnerabilites,
most much worse than the DoS attack described here.
-- Jeffrey T. Hutzelman (N3NHS) <jhutz+@cmu.edu>
Systems Programmer
School of Computer Science - Research Computing Facility
Carnegie Mellon University - Pittsburgh, PA
This archive was generated by hypermail 2b30 : Fri Apr 13 2001 - 14:03:02 PDT