Ubuntu 16.04 local, global menus, CLI contents disappear

[Free Beachler]

Description: Ubuntu 16.04.1 LTS
Release: 16.04

I cannot seem to find a bug report or other information to illuminate why menus disappear in Ubuntu 16.04 and how to fix it. UPDATE: not only do menus disappear, but CLI content becomes illegible making it useless. In the CLI users see what they type in a normal font-size, but all responses from the system are illegible in the CLI.

I'm marking this as a "security" bug because I feel that anytime the GUI and CLI are unusable, there's a security risk. If this had happened during a process of creating/editing existing security resources, either on this machine or remotely, unexpected results could occur.

Screenshota are attached and the system Unity Desktop is unusable after this occurs for practical intents and purposes. I can't even obtain the 16.04 LTS version number to complete this bug report. Not shown in the screenshot is that the content(s) inside a Firefox browser window render OK. However, content inside a system window such as File Manager does NOT render OK.

Unfortunately I don't know the steps to reproduce this bug. However after usage today I suspect this occurred after opening a regular JPG using the default Ubuntu image viewer, and then opening it in Gimp.

Unfortunately I do not see any way to recover from this to see the results of 'lsb_release -rd', and obviously System/About is useless, so I will have to complete such information after I reboot and/or upon request.

I looked for other bug reports but couldn't find one. https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1312137 isn't this bug. https://bugs.launchpad.net/ubuntu/+source/bamf/+bug/1532226 isn't this bug.

Thanks in advance for helping fix this bug!

[Free Beachler (tenacious)]

After rebooting I'm having difficulty reproducing the issue but this has demonstrated itself as a repeatable bug.

[Tyler Hicks (tyhicks)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. We appreciate the difficulties you are facing, but this appears to be a "regular" (non-security) bug. I have unmarked it as a security issue since this bug does not show evidence of allowing attackers to cross privilege boundaries nor directly cause loss of data/privacy. Please feel free to report any other bugs you may find.

[Free Beachler (tenacious)]

Thank you for providing feedback. I disagree with the assessment since the only (known) way to recover is a reboot, thus it seems conceivable that an attacker who knows how to exploit this issue may be able to deceive a user into an action which may lose data, or perhaps cause them to click on a GUI element that provides other attack vectors. I don't intend to imply that any bug which renders the GUI useless is a security issue.

[Free Beachler (tenacious)]

To clarify/repeat, I don't intend to imply that a bug which renders both GUI and CLI useless, requiring a reboot, is a security issue.