Re: FUSE merging?

From: Frank van Maarseveen
Date: Fri Jul 01 2005 - 04:40:41 EST


On Fri, Jul 01, 2005 at 08:36:02AM +0200, Miklos Szeredi wrote:
>
> Here's a description of a theoretical DoS scenario:
>
> http://marc.theaimsgroup.com/?l=linux-fsdevel&m=111522019516694&w=2

So the open() hangs indefinately. but what if blackhat tries to install
a package from a no longer existing server on /net or via NFS?

A user supplied pathname is not to be trusted by any setuid (or full
root) program.

Another example: I'm not sure if there are still /dev/tty devices which
may block indefinately upon open() but:

- I have yet to see a setuid program which always uses O_NONBLOCK
when opening user supplied pathnames.
- one cannot stat() and then open() because that gives a race.

--
Frank
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