The way I found this was by testing the SRU in vivid - for some reason the X server was sending Request packets with a addresses field empty. Other Ubuntu releases are not doing this. I haven't yet investigated if why it was doing this.
** Also affects: lightdm (Ubuntu) Importance: Undecided Status: New ** Also affects: lightdm (Ubuntu Wily) Importance: Undecided Status: New ** Changed in: lightdm (Ubuntu) Status: New => Fix Committed ** Changed in: lightdm (Ubuntu Wily) Status: New => Fix Committed ** Changed in: lightdm (Ubuntu) Importance: Undecided => Critical ** Changed in: lightdm (Ubuntu Wily) Importance: Undecided => Critical -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/1516831 Title: XDMCP Request packet with no addresses crashes LightDM Status in Light Display Manager: Fix Released Status in Light Display Manager 1.14 series: Fix Released Status in Light Display Manager 1.16 series: Fix Released Status in lightdm package in Ubuntu: Fix Committed Status in lightdm source package in Wily: Fix Committed Bug description: [Impact] If LightDM receives an XDMCP Request packet with no addresses then it will attempt to access a negative index into an array and crash. This only occurs if the XDMCP server is enabled. [Test Case] 1. Enable XDMCP in lightdm.conf: [XDMCPServer] enabled=true 2. Start LightDM 3. Send an XDMCP Request without an empty addresses field (valid XDMCP servers do not send this). Expected result: The request is ignored. Observed result: LightDM crashes. To manage notifications about this bug go to: https://bugs.launchpad.net/lightdm/+bug/1516831/+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