Bug 1076240 - scary information leakage
Summary: scary information leakage
Alias: None
Product: Fedora
Classification: Fedora
Component: xorg-x11-drv-nouveau
Version: 20
Hardware: Unspecified
OS: Unspecified
Target Milestone: ---
Assignee: Ben Skeggs
QA Contact: Fedora Extras Quality Assurance
Depends On:
TreeView+ depends on / blocked
Reported: 2014-03-13 21:00 UTC by Peter Backes
Modified: 2015-06-29 19:27 UTC (History)
3 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2015-06-29 19:27:12 UTC
Type: Bug

Attachments (Terms of Use)

Description Peter Backes 2014-03-13 21:00:56 UTC
Description of problem:
After I boot a machine just turned on (power disconnected before), the lightdm background looks somewhat corrupted, containing mostly black, but some pixels in bright colors.

If I login to a session, then exit the session with a reboot, as soon as lightdm turns up the background now displays fragements of my screen from the session from BEFORE THE REBOOT! How freaking scary is that?

Just think about it, if I enter a password in the terminal in cleartext for some reason, it is now displayed to whoever rebooted the machine!

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. login to a session
2. browse a little bit with firefox
3. from session, reboot
4. after reboot, watch lightdm background

Actual results:
it displays various fragments of the session from before reboot, from firefox as well as from the desktop

Expected results:
it displays /usr/share/backgrounds/default.png as configured in /etc/lightdm/lightdm-gtk-greeter.conf

Additional info:
how is this even theoretically possible given that linux is supposed to zero pages before mapping? http://permalink.gmane.org/gmane.linux.kernel.kernelnewbies/40544 Does a different policy apply to graphics memory?

One would assume it's hard and takes lots of effort to get information from other processes. This keeps the information over a reboot. And conveniently displays it. Scary stuff.

Comment 2 Fedora End Of Life 2015-05-29 11:14:42 UTC
This message is a reminder that Fedora 20 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 20. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
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Comment 3 Fedora End Of Life 2015-06-29 19:27:12 UTC
Fedora 20 changed to end-of-life (EOL) status on 2015-06-23. Fedora 20 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

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