DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:mime-version:from:date:message-id:subject:to
	:content-type; q=dns; s=default; b=iBy4M5Lfhcc5Mqk0C7iq5vGrjg5YX
	84Y/ocSHleLXwbh0GV+USg+YeahZES30v5XvXnkvrZ3qhybkdpSAoMj7MUrGB6Ed
	fjdpaddZv4lZwj8PticA24JLGLLvFaKTcU3zssq20PBUHCcIbb9BoA8yWfBv39Uz
	BnYf7Qo+m/7Aew=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
MIME-Version: 1.0
From: John Selbie <jselbie AT gmail DOT com>
Date: Mon, 2 Mar 2020 20:26:00 -0800
Message-ID: <CAJn6YFB_qVF-fNpX_CiWhnigaKMWJo-sOWM5C0ZJ89Ez1hvcBg@mail.gmail.com>
Subject: ASLR revisited
To: cygwin AT cygwin DOT com
Content-Type: text/plain; charset="UTF-8"

For my open source project, I publish source code for Unix written in C++.
And as a convenience, I publish Win32 binaries compiled with Cygwin's g++
build. I bundled the compiled EXE along with the dependent Cygwin DLLs
(cygcrypto, cyggcc, cycstdc++, cygwin1, and cygz.dll).

Someone rang me up today and said, "We're about to go live with your
pre-compiled binaries for Windows, but our compliance testing detected your
code isn't using ASLR (Address Space Layout Randomization).  Can you fix?"

A quick internet search reveals that Cygwin has a compatibility issue with
ASRL. Process Explorer from sysinternals.com reveals that the process runs
without ASLR.

I tried using the Windows 10 Exploit Protection Panel - and specifying an
exception for this executable to have mandatory ASLR. That results in the
code no longer running.  Although the alternate option of "Botton-up ASLR"
did allow the code to run, but Process Explorer still doesn't show it
running with ASLR.

Is there a workaround for allowing Cygwin code to have ASLR?  I don't need
the fork() function.

Thanks,
jrs

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple