X-Recipient:	archive-cygwin AT delorie DOT com
X-Original-To:	cygwin AT cygwin DOT com
Delivered-To:	cygwin AT cygwin DOT com
DMARC-Filter:	OpenDMARC Filter v1.3.2 sourceware.org 6E864385ED4A
Authentication-Results:	sourceware.org; dmarc=none (p=none dis=none)
	header.from=roc.cs.umass.edu
Authentication-Results:	sourceware.org;
	spf=none smtp.mailfrom=moss AT roc DOT cs DOT umass DOT edu
From:	Eliot Moss <moss AT roc DOT cs DOT umass DOT edu>
Mime-Version:	1.0 (1.0)
Subject:	Re: Mandatory ASLR breaks Cygwin - Windows 10
Date:	Tue, 25 Aug 2020 10:34:31 -0400
Message-Id:	<4AA035EB-1325-4C1B-B399-28FC9176F203@roc.cs.umass.edu>
References:	<!&!AAAAAAAAAAAuAAAAAAAAAALnY9Oyj39Bmm+bZ+AsdEYBAMO2jhD3dRHOtM0AqgC7tuYAAAAAAA4AABAAAACpqdOkYbaoTKteTcuy1wdvAQAAAAA=@linuxandria.com>
In-Reply-To:	<!&!AAAAAAAAAAAuAAAAAAAAAALnY9Oyj39Bmm+bZ+AsdEYBAMO2jhD3dRHOtM0AqgC7tuYAAAAAAA4AABAAAACpqdOkYbaoTKteTcuy1wdvAQAAAAA=@linuxandria.com>
To:	Alexandria Cortez <admin AT linuxandria DOT com>
X-Mailer:	iPhone Mail (17G68)
X-Spam-Status:	No, score=1.5 required=5.0 tests=BAYES_20, KAM_DMARC_STATUS,
	KAM_LAZY_DOMAIN_SECURITY, KAM_NUMSUBJECT, SPF_HELO_NONE, SPF_NONE,
	TXREP autolearn=no autolearn_force=no version=3.4.2
X-Spam-Level:	*
X-Spam-Checker-Version:	SpamAssassin 3.4.2 (2018-09-13) on
	server2.sourceware.org
X-BeenThere:	cygwin AT cygwin DOT com
X-Mailman-Version:	2.1.29
List-Id:	General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Archive:	<https://cygwin.com/pipermail/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe:	<https://cygwin.com/mailman/listinfo/cygwin>,
	<mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
Cc:	cygwin AT cygwin DOT com
Sender:	"Cygwin" <cygwin-bounces AT cygwin DOT com>
X-MIME-Autoconverted:	from base64 to 8bit by delorie.com id 07PEZ5xf001141

It’s intentional; too long to explain in detail on phone, but fork requires each dll to load in the child at the same address as in the parent, and ASLR interferes with achieving that.

Sent from my iPhone

> On Aug 25, 2020, at 10:17 AM, Alexandria Cortez <admin AT linuxandria DOT com> wrote:
> 
> I was experimenting with security settings this morning on windows, and
> after changing Mandatory ASLR (Windows Security -> App and Browser Control
> -> Exploit Protection) to default on, no Cygwin programs that rely on the
> Cygwin dll would start, stating that a resource was temporarily unavailable
> and could not fork. Rebasell, bash, you name it crashed and would not start.
> After some investigation, turning off that setting allows Cygwin to work.
> 
> 
> 
> Now the next question: why does this not work? Is this intended behavior or
> a bug? Having that setting turned on seems like a good idea from a security
> standpoint, and who knows it  may eventually become default.
> 
> 
> 
> Regards,
> 
> Alexandria C.
> 
> <cygcheck.out>
> --
> Problem reports:      https://cygwin.com/problems.html
> FAQ:                  https://cygwin.com/faq/
> Documentation:        https://cygwin.com/docs.html
> Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple

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

- Raw text -