I have discovered a side effect to this bug that implies a security vulnerability.
You are in graphical tty7 and select the "switch user" option. The xserver gets stuck trying to open a new graphical tty. You have black screen on tty8. You cannot go back to tty7. Still you can open a non-graphical tty (tty1-tty6). You have to login on the new tty, so you write username and password. But all keyboard activity is still being captured on original tty7!! You are exposing your login and password credentials (at least) to the foreground application on tty7. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/1247189 Title: Ubuntu freezes completely when switching user Status in “linux” package in Ubuntu: Confirmed Status in “xserver-xorg-video-intel” package in Ubuntu: Confirmed Bug description: I'm using a freshly installed Ubuntu 13.10. As soon as I click on a different user I want to switch to in the gearbox menu I get a black screen and nothing else is happening. I'm still able to SSH to that box and top does not show any process taking 100% CPU. Alt+sysrq+b is able to reboot the system. I had no problem like this with Ubuntu 13.04 on the same computer. WORKAROUND: Disable the nvidia card in the BIOS. ProblemType: Bug DistroRelease: Ubuntu 13.10 Package: lightdm 1.8.2-0ubuntu1 ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3 Uname: Linux 3.11.0-12-generic x86_64 NonfreeKernelModules: wl ApportVersion: 2.12.5-0ubuntu2.1 Architecture: amd64 Date: Fri Nov 1 17:40:41 2013 InstallationDate: Installed on 2013-10-30 (2 days ago) InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1) MarkForUpload: True SourcePackage: lightdm UpgradeStatus: No upgrade log present (probably fresh install) --- ApportVersion: 2.12.7-0ubuntu3 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: ubuntu 2816 F.... pulseaudio CasperVersion: 1.336ubuntu1 CurrentDesktop: Unity DistroRelease: Ubuntu 14.04 IwConfig: eth0 no wireless extensions. lo no wireless extensions. LiveMediaBuild: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140105) MachineType: Acer Aspire 5755G MarkForUpload: True Package: linux (not installed) ProcFB: 0 inteldrmfb 1 nouveaufb ProcKernelCmdLine: file=/cdrom/preseed/username.seed boot=casper cdrom-detect/try-usb=true noprompt floppy.allowed_drive_mask=0 ignore_uuid initrd=/casper/initrd.lz quiet splash -- ProcVersionSignature: Ubuntu 3.12.0-7.15-generic 3.12.4 RelatedPackageVersions: linux-restricted-modules-3.12.0-7-generic N/A linux-backports-modules-3.12.0-7-generic N/A linux-firmware 1.119 Tags: trusty Uname: Linux 3.12.0-7-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo dmi.bios.date: 08/09/2012 dmi.bios.vendor: Acer dmi.bios.version: V1.21 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: JV51_HR dmi.board.vendor: Acer dmi.board.version: Base Board Version dmi.chassis.type: 10 dmi.chassis.vendor: Acer dmi.chassis.version: V1.21 dmi.modalias: dmi:bvnAcer:bvrV1.21:bd08/09/2012:svnAcer:pnAspire5755G:pvrV1.21:rvnAcer:rnJV51_HR:rvrBaseBoardVersion:cvnAcer:ct10:cvrV1.21: dmi.product.name: Aspire 5755G dmi.product.version: V1.21 dmi.sys.vendor: Acer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1247189/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
