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From: "Alexandria Cortez" <admin@linuxandria.com>
To: "'Eliot Moss'" <moss@roc.cs.umass.edu>
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 <4AA035EB-1325-4C1B-B399-28FC9176F203@roc.cs.umass.edu>
In-Reply-To: <4AA035EB-1325-4C1B-B399-28FC9176F203@roc.cs.umass.edu>
Subject: RE: Mandatory ASLR breaks Cygwin - Windows 10
Date: Tue, 25 Aug 2020 10:36:55 -0400
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That's unfortunate. 

Is there any plans to implement a workaround in the future? Seeing as Cygwin is only one of two programs I've noticed that are broken with it on, it would be nice to be able to have it on from a security perspective.

-----Original Message-----
From: Eliot Moss <moss@roc.cs.umass.edu> 
Sent: Tuesday, August 25, 2020 10:35 AM
To: Alexandria Cortez <admin@linuxandria.com>
Cc: cygwin@cygwin.com
Subject: Re: Mandatory ASLR breaks Cygwin - Windows 10

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@linuxandria.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>
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