Re: [RFC][PATCH 4/3] vfs: Allow rmdir to remove mounts in all but the current mount namespace

[Eric W. Biederman]

Miklos Szeredi <miklos@xxxxxxxxxx> writes:

> On Thu, Oct 10, 2013 at 1:43 PM, Eric W. Biederman
>> Miklos if you as the fuse maintainer aren't worried about network
>> filesystems, and multiple namespaces I won't worry either.  Especially
>> since modern versions of fuse aren't affected.
>
> I think the above conditions (local mount blocks unlink/rename) are
> enough to prevent most of the problems, of which there aren't many in
> any case.

Dumb question.

What prevents someone setting up a race between the fusermount
permission checks and replacing the destination with a symlink, perhaps
to /etc/shadow?

Do we need a MS_NOFOLLOW?

Eric

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/