Re: [PATCH] private mounts

From: Lars Marowsky-Bree
Date: Wed Apr 27 2005 - 10:52:06 EST

On 2005-04-27T17:33:20, Martin Mares <mj@xxxxxx> wrote:

> > It is not there for the purpose of protecting user's data. Rather for
> > protecting other users (including root) from unknowingly entering the
> > FUSE directory and thus leaking otherwise inaccessible information
> > (exact file operations performed) to the mount owner.
> Huh? Do you really suppose that there could be anything secret in the
> operations somebody else is performing on your files?

It is certainly an information leak not otherwise available. And with
the ability to change the layout underneath, you might trigger bugs in
root programs: Are they really capable of seeing the same filename
twice, or can you throw them into a deep recursion by simulating
infinitely deep directories/circular hardlinks...?

Certainly a useful tool for hardening applications, but I can see the
point of not wanting to let unwary applications run into a namespace
controlled by a user. Of course, this is sort-of similar to "find
-xdev", but I'm not sure whether it is not indeed new behaviour.

Lars Marowsky-Brée <lmb@xxxxxxx>

High Availability & Clustering
SUSE Labs, Research and Development
SUSE LINUX Products GmbH - A Novell Business

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