Subject: Re: PROT_EXEC mappings of vnodes -> VTEXT
To: None <cgd@broadcom.com>
From: Jason R Thorpe <thorpej@wasabisystems.com>
List: tech-kern
Date: 10/30/2001 09:25:02
On Tue, Oct 30, 2001 at 08:06:22AM -0800, cgd@broadcom.com wrote:
> thorpej@wasabisystems.com ("Jason R Thorpe") writes:
> > But even what you're suggesting wouldn't be "the right way". Add +x to
> > libc.so and then do "./libc.so". This isn't really what you want, either.
>
> Arguably that's a deficiency in sys_execve() then.
>
> But in any case, it's a _whole_ lot better than allowing a malicious
> user to cause any readable file to become unwritable (or, i guess, not
> open()able for write, right?).
Yes, but this problem is currently avoided with the VEXECMAP flag.
--
-- Jason R. Thorpe <thorpej@wasabisystems.com>