Bug 714693 - Content above dimensions of cleared display is still visible for locked screen session
Summary: Content above dimensions of cleared display is still visible for locked scree...
Keywords:
Status: CLOSED NEXTRELEASE
Alias: None
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: screen
Version: 6.3
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: rc
: ---
Assignee: Josef Ridky
QA Contact: BaseOS QE - Apps
URL:
Whiteboard:
Depends On: 714684 806803
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-06-20 13:07 UTC by Petr Pisar
Modified: 2016-07-25 08:29 UTC (History)
9 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of: 683733
Environment:
Last Closed: 2016-07-25 08:29:15 UTC
Target Upstream Version:


Attachments (Terms of Use)

Description Petr Pisar 2011-06-20 13:07:09 UTC
+++ This bug was initially created as a clone of Bug #683733 +++

+++ This bug was initially created as a clone of Bug #681600 +++

Description of problem:
There is a requirement for "clearing or overwriting TSF controlled display devices, making the current contents unreadable".

Screen only clears the display up to its dimensions, but not the content above it. By scrolling up with Shift+PgUp anything above those blanked dimensions is still visible. This behaviour does not seem to be desired and this should be fixed. One option/workaround could be to use no-scroll kernel boot argument.

Version-Release number of selected component (if applicable):
screen-4.0.3-15.el6.x86_64 (rhel6.0)
screen-4.0.3-16.el6.x86_64 (rhel6.1)

How reproducible:
always

Steps to Reproduce:
1. Update /etc/profile: 
cat >> /etc/profile << EOT
####
SCREENEXEC="screen"
export SCREENDIR=$HOME/.screen
if [ -w $(tty) ] ; then
        trap "exec $SCREENEXEC" 1 2 3 15
        echo -n 'Starting session in 2 seconds'
        sleep 2
        exec $SCREENEXEC
fi
EOT
2. Log into the system at runlevel 3 as any correct user
3. Work with some super secret information, e.g.:
for i in `seq 1 100` ; do cat /etc/profile ; done
4. Lock the screen session with "Ctrl+a x"
5. "scroll up" using "Shift+PgUp"
  
Actual results:
Everything that was above dimensions of cleared display is still visible.

Expected results:
When screen session is locked no other content than password prompt is visible, to meet requirement for "clearing or overwriting TSF controlled display devices, making the current contents unreadable".

Additional info:
This is not a regression against RHEL 6.0, David is checking RHEL 5.6 now ...

[...]
--- Additional comment from ppisar on 2011-06-10 13:08:43 GMT ---

FYI, F16 delivers kernel supporting "\E[3;J" sequence to clear scroll-back buffer.
-----

Based on discussion with Steve Grubb, I propose this feature for RHEL-6.2 as an
alternative to disabled scroll-back buffer.

Comment 1 RHEL Program Management 2011-07-06 01:01:59 UTC
This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
in the current release, Red Hat is unfortunately unable to
address this request at this time. Red Hat invites you to
ask your support representative to propose this request, if
appropriate and relevant, in the next release of Red Hat
Enterprise Linux. If you would like it considered as an
exception in the current release, please ask your support
representative.

Comment 2 Josef Ridky 2016-07-25 08:29:15 UTC
Red Hat Enterprise Linux version 6 is entering the Production 2 phase of its lifetime and this bug doesn't meet the criteria for it, i.e. only high severity issues will be fixed. Please see https://access.redhat.com/support/policy/updates/errata/ for further information.

This issue is fixed in Red Hat Enterprise Linux version 7.


Note You need to log in before you can comment on or make changes to this bug.