DavidEG, the next step is to fully reverse commit bisect from kernel 4.4 to 4.6 in order to identify the last bad commit, followed immediately by the first good one. Once this good commit has been identified, it may be reviewed for backporting. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection#How_do_I_reverse_bisect_the_upstream_kernel.3F ?
Please note, finding adjacent kernel versions is not fully commit bisecting. After the fix commit (not kernel version) has been identified, then please mark this report Status Confirmed. Thank you for your understanding. Helpful bug reporting tips: https://wiki.ubuntu.com/ReportingBugs ** Tags added: kernel-fixed-upstream-4.6 latest-bios-2.00 needs-reverse- bisect ** Changed in: linux (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1585081 Title: Switching user freezes system Status in linux package in Ubuntu: Incomplete Bug description: Just doing this my system freezes: 1. Click on the top right gear icon. 2. Select a different user account. Login screen appears briefly, then black screen and the system is death: BUG: unable to handle kernel NULL pointer dereference at 0000000000000248 IP: [<ffffffffc0258eb2>] amdgpu_vm_grab_id+0x122/0x310 [amdgpu] PGD 0 Oops: 0000 [#1] SMP Modules linked in: ... (See attached syslog for more) ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.4.0-22-generic 4.4.0-22.40 ProcVersionSignature: Ubuntu 4.4.0-22.40-generic 4.4.8 Uname: Linux 4.4.0-22-generic x86_64 ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: david 2739 F.... pulseaudio /dev/snd/controlC1: david 2739 F.... pulseaudio CurrentDesktop: Unity Date: Tue May 24 08:54:13 2016 HibernationDevice: RESUME=UUID=d225720a-fc40-49a3-9182-17d278d40460 InstallationDate: Installed on 2015-06-29 (329 days ago) InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422) MachineType: TOSHIBA SATELLITE S50-B ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-22-generic.efi.signed root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-4.4.0-22-generic N/A linux-backports-modules-4.4.0-22-generic N/A linux-firmware 1.157 SourcePackage: linux UpgradeStatus: Upgraded to xenial on 2016-04-22 (31 days ago) dmi.bios.date: 12/02/2014 dmi.bios.vendor: INSYDE Corp. dmi.bios.version: 2.00 dmi.board.asset.tag: Type2 - Board Asset Tag dmi.board.name: Type2 - Board Product Name1 dmi.board.vendor: Type2 - Board Vendor Name1 dmi.board.version: Type2 - Board Version dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: OEM Chassis ManuFacturer dmi.chassis.version: OEM Chassis Version dmi.modalias: dmi:bvnINSYDECorp.:bvr2.00:bd12/02/2014:svnTOSHIBA:pnSATELLITES50-B:pvrPSPQEE-00F00JEN:rvnType2-BoardVendorName1:rnType2-BoardProductName1:rvrType2-BoardVersion:cvnOEMChassisManuFacturer:ct10:cvrOEMChassisVersion: dmi.product.name: SATELLITE S50-B dmi.product.version: PSPQEE-00F00JEN dmi.sys.vendor: TOSHIBA To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1585081/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
