Re: non-executable stack (via PT_GNU_STACK) not being enforced

To: Brchk05 <brchk05@aim.com>
Cc: debian-security@lists.debian.org
Subject: Re: non-executable stack (via PT_GNU_STACK) not being enforced
From: Kees Cook <kees@debian.org>
Date: Sun, 10 Oct 2010 09:07:23 -0700
Message-id: <[🔎] 20101010160723.GH4991@outflux.net>
In-reply-to: <[🔎] 8CD3699ADB98387-16BC-1C215@webmail-m044.sysops.aol.com>
References: <[🔎] 8CD3699ADB98387-16BC-1C215@webmail-m044.sysops.aol.com>

Hi,

On Sun, Oct 10, 2010 at 09:53:40AM -0400, Brchk05 wrote:
> However, I am able to inject and execute shellcode from a stack local character buffer in both versions.  Is there another system option I am unaware of that affects enforcement?  Is enforcement not supported for my system version?

Your CPU may not support NX enforcement. Check your dmesg output, and your
cpuflags line in /proc/cpuinfo for "nx".

See https://wiki.ubuntu.com/Security/Features#nx though ignore the nx-emu
notes, as that's not in Debian.

-Kees

-- 
Kees Cook                                            @debian.org

Reply to:

Follow-Ups:
- Re: non-executable stack (via PT_GNU_STACK) not being enforced
  - From: Brchk05 <brchk05@aim.com>

References:
- non-executable stack (via PT_GNU_STACK) not being enforced
  - From: Brchk05 <brchk05@aim.com>

Prev by Date: non-executable stack (via PT_GNU_STACK) not being enforced
Next by Date: Re: non-executable stack (via PT_GNU_STACK) not being enforced
Previous by thread: non-executable stack (via PT_GNU_STACK) not being enforced
Next by thread: Re: non-executable stack (via PT_GNU_STACK) not being enforced
Index(es):
- Date
- Thread