From: Brian Inglis <Brian.Inglis@SystematicSw.ab.ca>
To: cygwin@cygwin.com
Subject: Re: W10 Mandatory ASLR default
Date: Fri, 16 Feb 2018 06:41:00 -0000 [thread overview]
Message-ID: <327030c8-7dfa-8e57-eb70-45e890f8aac2@SystematicSw.ab.ca> (raw)
In-Reply-To: <aff8daa3-a958-acd2-66ca-579751981c9a@ferzkopp.net>
On 2018-02-14 00:36, Andreas Schiffler wrote:
> On 2/13/2018 11:17 PM, Thomas Wolff wrote:
>> Am 14.02.2018 um 04:25 schrieb Brian Inglis:
>>> On 2018-02-12 21:58, Andreas Schiffler wrote:
>>>> Found the workaround (read: not really a solution as it leaves the system
>>>> vulnerable, but it unblocks cygwin)
>>>> - Go to Windows Defender Security Center - Exploit protection settings
>>>> - Disable System Settings - Force randomization for images (Mandatory ASLR) and
>>>> Randomize memory allocations (Bottom-up ASLR) from "On by default" to "Off by
>>>> default"
>>>>
>>>> Now setup.exe works and can rebase everything; after that Cygwin Terminal
>>>> starts as a working shell without problems.
>>>> @cygwin dev's - It seems one of the windows updates (system is on 1709 build
>>>> 16299.214) might have changed my ASLR settings to "system wide mandatory" (i.e.
>>>> see
>>>> https://blogs.technet.microsoft.com/srd/2017/11/21/clarifying-the-behavior-of-mandatory-aslr/
>>>> for info) so that the cygwin DLLs don't work correctly anymore (i.e. see old
>>>> thread about this topic here
>>>> https://www.cygwin.com/ml/cygwin/2013-06/msg00092.html).
>>>> It would be good to devize a test for the setup.exe that
>>>> checks the registry (likely
>>>> [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\kernel])
>>>> for this state and alerts the user.
>>> I'm on W10 Home 1709/16299.192 (slightly older).
>>> Under Windows Defender Security Center/App & browser control/Exploit
>>> protection/Exploit protection settings/System settings/Force randomization for
>>> images (Mandatory ASLR) - "Force relocation of images not compiled with
>>> /DYNAMICBASE" is "Off by default", whereas Randomize memory allocations
>>> (Bottom-up ASLR) - "Randomize locations for virtual memory allocations." and all
>>> other settings are "On by default".
>>> Under Windows Defender Security Center/App & browser control/Exploit
>>> protection/Exploit protection settings/Program settings various .exes have 0-2
>>> system overrides of settings.
>>> It would be nice if one of the project volunteers with Windows threat mitigation
>>> knowledge could look at these, to see if there is a better approach.
>> I guess Andreas' suggestion is confirmed by
>> https://github.com/mintty/wsltty/issues/6#issuecomment-361281467
> Here is the registry state:
> Mandatory ASLR off
> Windows Registry Editor Version 5.00
> [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\kernel]
> "MitigationOptions"=hex:00,02,22,00,00,00,00,00,00,00,00,00,00,00,00,00
> Mandatory ASLR on
> Windows Registry Editor Version 5.00
> [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\kernel]
> "MitigationOptions"=hex:00,01,21,00,00,00,00,00,00,00,00,00,00,00,00,00
Could setup be updated to reset Mandatory ASLR if the reg keys exist, or an
/etc/postinstall/[0z]p_disable_mandatory_aslr.sh script do a check and reset?
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
--
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
next prev parent reply other threads:[~2018-02-16 6:41 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-11 8:18 cygwin stopped working Andreas Schiffler
2018-02-11 10:42 ` Doug Henderson
2018-02-12 1:16 ` Andreas Schiffler
2018-02-12 2:30 ` Brian Inglis
2018-02-12 16:48 ` Jostein Berntsen
2018-02-13 4:58 ` Andreas Schiffler
2018-02-14 1:42 ` Bryan Zimmer
2018-02-14 7:53 ` Eliot Moss
2018-02-14 8:49 ` Marco Atzeri
2018-02-14 3:25 ` W10 Mandatory ASLR default (was: cygwin stopped working) Brian Inglis
2018-02-14 7:17 ` W10 Mandatory ASLR default Thomas Wolff
2018-02-14 7:36 ` Andreas Schiffler
2018-02-16 6:41 ` Brian Inglis [this message]
2018-02-18 19:43 ` Andreas Schiffler
2018-02-18 20:07 ` Achim Gratz
2018-02-18 22:40 ` Brian Inglis
2018-02-12 18:16 ` cygwin stopped working Achim Gratz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=327030c8-7dfa-8e57-eb70-45e890f8aac2@SystematicSw.ab.ca \
--to=brian.inglis@systematicsw.ab.ca \
--cc=cygwin@cygwin.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).