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    Subjectunionfs unusable on multiuser systems (was Re: [PATCH 01/24] Unionfs: Documentation)
    Hi!

    > > > That statement is meant to scare people away from modifying the lower fs :)
    > > > I tortured unionfs quite a bit, and it can oops but it takes some effort.
    > > But isn't it then potential DOS? If you happen to union two filesystems
    > > and an untrusted user has write access to both original filesystem and
    > > the union, then you say he'd be able to produce oops? That does not
    > > sound very secure to me... And if any secure use of unionfs requires
    > > limitting access to the original trees, then I think it's a good reason
    > > to implement it in unionfs itself. Just my 2 cents.
    >
    > You mean somebody like, say, a perfectly innocent process working on the
    > NFS server or some other client that is oblivious to the existence of
    > unionfs stacks on your particular machine?
    > To me, this has always sounded like a showstopper for using unionfs with
    > a remote filesystem.

    Actually, it is worse than that. find / (and updatedb) *will* write to
    all the filesystems (atime).

    Expecting sysadmins to know/prevent this seems like expecting quite a
    lot from them. Sounds like a show stopper to me :-(....
    Pavel
    --
    Thanks for all the (sleeping) penguins.
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