X-Recipient:	archive-cygwin AT delorie DOT com
DomainKey-Signature:	a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:subject:to:message-id:date:mime-version
	:content-type:content-transfer-encoding; q=dns; s=default; b=Tfu
	IDvzEKYL960/pCtI7MGhEoqhSFXwVEpHFUEfcuntc1qjS/wKuuREiGp2lbzCEmPh
	4Yhm1/NjYYCbcMFWf+apyXlahqPKh3ohONKZmPBGirWazQuTjCvBy+tlkY6i04MM
	MgN7KoxJoQeZrB4Nb4Q7ZMBIGFhwE7ZU0whLvK8A=
DKIM-Signature:	v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:subject:to:message-id:date:mime-version
	:content-type:content-transfer-encoding; s=default; bh=vuWPuTTrS
	WLaOIaYdNKhELQgcHM=; b=x1SzrEebSB8yvOK+Cy+VGOJ6Er+uVmXJ08YNwB77J
	ijUeyY4RWVvtEQfVrvQVz5Txlq4nE0HxIKsewVTtGz7ndKBhHZHQJM2sRNZMfo8Q
	tqqVRzGIPo8DV7PHiRs20rijZVrFC0+2NjF4Le0qJV5YLPATN0syO3lvQWR8+isY
	U8=
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com
Authentication-Results:	sourceware.org; auth=none
X-Spam-SWARE-Status:	No, score=-3.1 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.1 spammy=Package, fairly, UID, cygwin-patches AT cygwin DOT com
X-HELO:	smtp-out6.electric.net
From:	Tim Adye <T DOT J DOT Adye AT rl DOT ac DOT uk>
Subject:	ssh-agent doesn't die
To:	<cygwin AT cygwin DOT com>
Message-ID:	<319e26c0-32f0-40b7-2137-c7de170a3486@rl.ac.uk>
Date:	Fri, 27 Sep 2019 00:42:44 +0100
User-Agent:	Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0
MIME-Version:	1.0
X-EsetResult:	clean, is OK
X-EsetId:	37303A290F3E23686C7566
X-Outbound-IP:	130.246.132.232
X-Env-From:	tim DOT adye AT stfc DOT ac DOT uk
X-Proto:	esmtps
X-Revdns:	exch01.rl.ac.uk
X-TLS:	TLSv1.2:ECDHE-RSA-AES256-SHA384:256
X-Authenticated_ID:
X-PolicySMART:	3590380
X-IsSubscribed:	yes
Note-from-DJ:	This may be spam

Hi,

I have noticed a (new?) problem with using ssh-agent to start a session, 
eg. with

   ssh-agent xterm &

When the xterm (or whatever) command completes, the ssh-agent process is 
still left running in the background. It should stop once its subprocess 
is done.

As a simple test example, consider:

/bin/ssh-agent /bin/sleep 10

While the sleep is still running, ps shows:

       PID    PPID    PGID     WINPID   TTY         UID    STIME COMMAND
      1694    1693    1694       1576  ?          22534 00:01:10 
/usr/bin/ssh-agent
      1653       1    1653      11740  cons1      22534 00:00:37 
/usr/bin/bash
      1693    1653    1693       1552  cons1      22534 00:01:10 
/usr/bin/sleep

One oddity is that ssh-agent is listed as a subprocess of sleep, not the 
other way round. pstree shows this clearly:

?-+-bash---pstree
   `-bash---sleep---ssh-agent

Once the sleep finishes, ps shows:

       PID    PPID    PGID     WINPID   TTY         UID    STIME COMMAND
      1694    1693    1694       1576  ?          22534 00:01:10 
/usr/bin/ssh-agent
      1653       1    1653      11740  cons1      22534 00:00:37 
/usr/bin/bash

ie. ssh-agent is still running, though its PPID no longer exists.

I'm using the latest release versions of cygwin and openssh:

Cygwin Package Information
Package              Version        Status
cygwin               3.0.7-1        OK
openssh              8.0p1-2        OK

with Windows 10 1803 (2019-09 update). I use Sophos AV 10.8 with HitmanPro.

Previously, I haven't had this problem: ssh-agent stopped when it's 
subprocess stopped. I updated from Cygwin 2.10-1 (and contemporaneous 
openssh) fairly recently, and it's possible the problem started then. Or 
it could have been a Windows minor update, AV update, or some other 
setting change I made. Sorry I couldn't pin it down further.

Is it just me that sees this, or could it be a bug in ssh-agent or Cygwin?

If it is just me, my first suspicion would be HitmanPro, which 
previously caused silent failures with an earlier version of Cygwin (I 
reported in cygwin-patches AT cygwin DOT com, June 2018). That bug is fixed, 
but maybe this is something new. If we can rule out a more general 
Cygwin bug, I can ask my IT support to try disabling the HitmanPro to test.

Thanks,
Tim.


--
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

- Raw text -