Well, ignore what I wrote above. The bug occured to me this morning. I still have the kernel trace in the syslog, but taking a closer look at my logs, it seems it occured earlier and not just when reactivating the screen.
Might be related to the displaying of notification by the locked screen. I'll try to disable that. ** Attachment added: "syslog" https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/1685141/+attachment/4869026/+files/syslog -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-screensaver in Ubuntu. https://bugs.launchpad.net/bugs/1685141 Title: System freezes after locking screen Status in gnome-screensaver package in Ubuntu: Confirmed Bug description: When locking the screen or whenever the screensaver starts automatically, I cannot log in again, but my system completely freezes and I have to restart the computer. In most cases I was able to do the restart by pressing Alt-REISUB, in some cases however I had to do a hard reset. This is a new bug in zesty (Ubuntu 17.04). In the previous version everything worked fine. I tested both the upgrade and a fresh new installation on the same computer. Package is gnome-screensaver version 3.6.1-7ubuntu5. I attach an excerpt from my syslog. Hope this might help to find the bug. I installed zesty on another computer (laptop) as well and there the bug did not appear. So I assume it has something to do with the installed graphics card or graphics driver. Installed graphics card in this case is: NVIDIA Corporation GF108 [GeForce GT 630] (rev a1). Update: After a few days the bug now appears on the second computer as well. However, I could unlock the screen and continue working, until suddenly (an hour later or so) the whole system froze. I add the kernel-nullpointer-dereference syslog of this event (syslog2.txt) to the attachments for this bug. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/1685141/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

