Re: Non-admin users, /tmp/.X11-unix/X0 permissions

["Alan J. Flavell" <a dot flavell at physics dot gla dot ac dot uk>]

On Mon, 11 Apr 2005, Alan J. Flavell wrote:

> After one normal user has run Cygwin/X, the next user gets told that
> s/he can't write to /tmp/.X11-unix/X0
> 
> The reason seems to be that the directory /tmp/.X11-unix has
> the "t" bit set (drwxrwxrwt), which means that normal users
> aren't allowed to mess with files that they don't own.
> 
> Thus, the first user creates X0 with their ownership, the "file" then 
> hangs around till the second user tries to run Cygwin/X, and they get
> told they can't overwrite it.
> 
> The problem can be trivially resolved by removing the "t" bit from the 
> directory - but presumably that represents a security exposure?

[Sorry about the eccentric threading of this reply - I'm working from 
the mailing list archive on the web]

Alexander Gottwald replied:

> Does it help if the t flag is cleared?

Yes; as I said in the original posting, this seemed to be one way to 
resolve the problem. My concern was that the "t" bit was there for a 
reason, and taking it off would be a security issue, although I wasn't 
quite sure *what* security issue it would be.

> Then we could create the directory without the flag instead. I don't 
> care for filesystem security on windows anyway.

I'm uneasy, but I don't see any specific objection, and it resolves
the problem.

thanks for the responses.