From:	 Pavel Machek <pavel@suse.cz>
To:	 Larry McVoy <lm@work.bitmover.com>, Dave Jones <davej@suse.de>,
	 kernel list <linux-kernel@vger.kernel.org>
Subject: Re: Bitkeeper licence issues
Date:	 Tue, 19 Mar 2002 22:58:00 +0100

Hi!

> >  > > Pavel, the problem here is your fundamental distrust.  
> >  > By giving me binary-only installer you ask me to trust you. You ask me
> >  > to trust you without good reason [it only generates .tar.gz and
> >  > shellscript, why should it be binary? Was not shar designed to handle
> >  > that?], and that's pretty suspect.
> > 
> >  Bitmover doing anything remotely suspect in an executable installer
> >  would be commercial suicide, do you distrust realplayer too?
> 
> And all our installer does, and I will give you the code if you want it,
> I'd be happy to even have Pavel audit it, is make two arrays, 

Okay, you wanted audit ;-).

> main()
> {
>         char    installer_name[200];
>         char    data_name[200];
>         char    cmd[2048];
>         int     fd;
> 
>         fprintf(stderr, "Please wait while we unpack the installer...");
>         sprintf(installer_name, "/tmp/installer%d", getpid());
>         fd = creat(installer_name, 0777);

If nasty user on same system creates symlink (ln -s /etc/passwd
/tmp/installer123), he may overwrite any file on the system. You probably want

fd = open(installer_name, O_WRONLY | O_TRUNC | O_CREAT | O_EXCL, 0755);

Same goes for data.
								Pavel
-- 
Casualities in World Trade Center: ~3k dead inside the building,
cryptography in U.S.A. and free speech in Czech Republic.
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