From: Brian Inglis <Brian.Inglis@SystematicSw.ab.ca>
To: cygwin@cygwin.com
Subject: Re: Mandatory ASLR breaks Cygwin - Windows 10
Date: Tue, 25 Aug 2020 09:13:19 -0600 [thread overview]
Message-ID: <cd134b34-3b17-3082-4da8-879583667070@SystematicSw.ab.ca> (raw)
In-Reply-To: <006c01d67aed$2f7f0660$8e7d1320$@linuxandria.com>
On 2020-08-25 08:36, Alexandria Cortez wrote:
> On Tuesday, August 25, 2020 10:35 AM, Eliot Moss wrote:>> On Aug 25, 2020, at 10:17 AM, Alexandria Cortez 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.
>> 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.
> 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.
Cygwin is an all-volunteer project - Someone Has To Do It!
Feel free to submit patches to support that in Cygwin under Windows.
A low level understanding of details of both is required.
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
This email may be disturbing to some readers as it contains
too much technical detail. Reader discretion is advised.
[Data in IEC units and prefixes, physical quantities in SI.]
next prev parent reply other threads:[~2020-08-25 15:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-25 14:16 Alexandria Cortez
2020-08-25 14:34 ` Eliot Moss
2020-08-25 14:36 ` Alexandria Cortez
2020-08-25 15:13 ` Brian Inglis [this message]
2020-08-25 15:25 ` [cygwin] " Jason Pyeron
2020-08-25 15:56 ` Eliot Moss
2020-08-25 21:49 ` Brian Inglis
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