Bug 1667519

Summary:	ssh-copy-id hangs when the remote system is out of space
Product:	Red Hat Enterprise Linux 8	Reporter:	Alicja Kario <hkario>
Component:	openssh	Assignee:	Jakub Jelen <jjelen>
Status:	CLOSED ERRATA	QA Contact:	Stanislav Zidek <szidek>
Severity:	unspecified	Docs Contact:
Priority:	medium
Version:	8.0	CC:	bsmejkal, jjelen, omoris, ssorce, szidek, tmraz
Target Milestone:	rc	Keywords:	Regression, Triaged
Target Release:	8.1
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	openssh-8.0p1-1.el8	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-11-05 22:41:07 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1682500
Bug Blocks:

Description Alicja Kario 2019-01-18 17:02:25 UTC

Description of problem:
When the remote system doesn't have the space to increase the size of authorized_keys or authorized_keys2, the ssh-copy-id command hangs indefinitely

Version-Release number of selected component (if applicable):
openssh-7.8p1-4.el8.x86_64

How reproducible:
always

Steps to Reproduce:
1. on remote system: ln -s /dev/full /home/$USER_NAME/.ssh/authorized_keys
2. on remote system: ln -s /dev/full /home/$USER_NAME/.ssh/authorized_keys2
3. locally: ssh-copy-id remote_user@remote_system

Actual results:
command hangs

Expected results:
cat: write error: No space left on device
ssh-copy-id return code of 1

Additional info:
This is regression from RHEL-7.

Comment 2 Jakub Jelen 2019-01-21 09:08:44 UTC

This is an issue with the check making sure there is a newline added to the authorized_keys file if it is missing initially (new in OpenSSH 7.5 or so).

The command that hangs is the following, which does not work with your reproducer (/dev/full returns unlimited stream of zeroes):

  tail -1c .ssh/authorized_keys

Even though I believe if the above would pass, the following does not have a check and would lead to fail without error message, because it is missing a guard " || exit 1" as the other write:

  echo >> .ssh/authorized_keys

At this moment, I see a simple solution for a real-world use cases (adding the check above), but I do not see a simple way how to make also your test happy.

I do not consider this as a blocker for 8.0 release so I postponed this bug to 8.1.

Comment 6 Simo Sorce 2019-05-22 12:16:10 UTC

Looks like patches are ready, updating status accordingly.

Comment 16 errata-xmlrpc 2019-11-05 22:41:07 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2019:3702