Re: install.c: please set unlink_dest_before_opening=false

[Robert Millan [ackstorm]]

On Thu, Mar 01, 2007 at 11:46:09AM +0100, Jim Meyering wrote:
> 
> The proposed change has another disadvantage.
> 
> If we don't break destination hard links, then we must write
> directly to the destination file, and that cannot be done atomically.
> This would definitely have security implications, so we can't
> change GNU install's default.

Why would that have security implications?  Once you open the file for
writing, nobody can do anything else with it.  From this POV, it is
as if the write were atomical.

OTOH, kernel implementations don't necessarily have to do that, but
I suppose if they opt for not doing it they'll provide some means to
preserve security?

-- 
Robert Millan

ACK STORM, S.L.  -  http://www.ackstorm.es/