Subject: Re: PROT_EXEC mappings of vnodes -> VTEXT
To: None <tech-kern@netbsd.org>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: tech-kern
Date: 10/30/2001 10:06:57
On Mon, Oct 29, 2001 at 09:53:05PM -0800, Chuck Silvers wrote:
> hi,
> 
> cool, I'm glad that this improves the situation so much.
> 
> but I really don't think we should allow unpriviledged users
> to cause any file they can read to become read-only just by
> mapping it with PROT_EXEC.  the VTEXT flag was originally used
> just for the read-only part, I was overloading it when I used it
> for affecting paging behaviour.

I would like to point out that were my suggestion of only allowing
mappings of files *with execute permission* to be set PROT_EXEC
implemented, this problem (user can make file read-only by mapping
it PROT_EXEC) would not exist.

Thor