Subject: Re: chroot jail for ftpd
To: Jonathan Stone <jonathan@DSG.Stanford.EDU>
From: Thor Lancelot Simon <firstname.lastname@example.org>
Date: 10/18/2001 19:38:36
On Thu, Oct 18, 2001 at 04:02:48PM -0700, Jonathan Stone wrote:
> >2) We don't even *check* to see if files have execute permission before
> > executing code that came from them via mmap -- for example, shared
> > libraries.
> And here we need to check noexec, not for x bits. If I can write a
> trojan .so file into a writable filesystem, I can set teh x bit on
> that trojan .so file, too.
So what? I suggest that the treatment should be exactly the same as for
executable files: the x bit should not be honored if noexec is set, and
if the x bit is not present or not honored, the code should not be executed.
Thor Lancelot Simon email@example.com
And now he couldn't remember when this passion had flown, leaving him so
foolish and bewildered and astray: can any man?