Public bug reported: I wanted to test how operating systems react if the DOS partition table of a storage medium was manipulated. I created a DOS partition table with a few extended partitions. Because extended partitions are constructed like a linked list, I linked the "NEXT" field of the last extended partition to the first extended partition. This way, I created a loop in the partition table. Tools like fdisk detect that something is fishy in this partition table and output an error message. To test how operating systems react to it, I copied this image to an USB storage device and plugged it to my computer.
The systemd/udev process that handles this device seems to not check the DOS partition table for sanity. The process "/lib/systemd/systemd-udevd --daemon" completely uses all CPU time and all available memory. This crashes the system. Sometimes, it is able to recover by killing the process, but not every time. I attached a screenshot (a real screenshot with a camera, because the system does not react anymore ;) ) of htop to show what the system does. Cheers, sqall ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: udev 204-5ubuntu20.19 ProcVersionSignature: Ubuntu 3.13.0-85.129-generic 3.13.11-ckt36 Uname: Linux 3.13.0-85-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.19 Architecture: amd64 CurrentDesktop: XFCE CustomUdevRuleFiles: 99-usb-disks.rules Date: Sat May 7 10:43:21 2016 InstallationDate: Installed on 2014-11-12 (541 days ago) InstallationMedia: Xubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140723) MachineType: Hewlett-Packard HP EliteBook 8460p ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.13.0-85-generic root=/dev/mapper/xubuntu--vg-root ro SourcePackage: systemd UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 12/22/2011 dmi.bios.vendor: Hewlett-Packard dmi.bios.version: 68SCF Ver. F.22 dmi.board.name: 161C dmi.board.vendor: Hewlett-Packard dmi.board.version: KBC Version 97.4A dmi.chassis.asset.tag: CZC2033ZHD dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.modalias: dmi:bvnHewlett-Packard:bvr68SCFVer.F.22:bd12/22/2011:svnHewlett-Packard:pnHPEliteBook8460p:pvrA0000C02:rvnHewlett-Packard:rn161C:rvrKBCVersion97.4A:cvnHewlett-Packard:ct10:cvr: dmi.product.name: HP EliteBook 8460p dmi.product.version: A0000C02 dmi.sys.vendor: Hewlett-Packard ** Affects: systemd (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug third-party-packages trusty ** Attachment added: "IMG_1299.JPG" https://bugs.launchpad.net/bugs/1579336/+attachment/4657885/+files/IMG_1299.JPG -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1579336 Title: systemd-udevd crashes system with manipulated DOS partition table Status in systemd package in Ubuntu: New Bug description: I wanted to test how operating systems react if the DOS partition table of a storage medium was manipulated. I created a DOS partition table with a few extended partitions. Because extended partitions are constructed like a linked list, I linked the "NEXT" field of the last extended partition to the first extended partition. This way, I created a loop in the partition table. Tools like fdisk detect that something is fishy in this partition table and output an error message. To test how operating systems react to it, I copied this image to an USB storage device and plugged it to my computer. The systemd/udev process that handles this device seems to not check the DOS partition table for sanity. The process "/lib/systemd/systemd- udevd --daemon" completely uses all CPU time and all available memory. This crashes the system. Sometimes, it is able to recover by killing the process, but not every time. I attached a screenshot (a real screenshot with a camera, because the system does not react anymore ;) ) of htop to show what the system does. Cheers, sqall ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: udev 204-5ubuntu20.19 ProcVersionSignature: Ubuntu 3.13.0-85.129-generic 3.13.11-ckt36 Uname: Linux 3.13.0-85-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.19 Architecture: amd64 CurrentDesktop: XFCE CustomUdevRuleFiles: 99-usb-disks.rules Date: Sat May 7 10:43:21 2016 InstallationDate: Installed on 2014-11-12 (541 days ago) InstallationMedia: Xubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140723) MachineType: Hewlett-Packard HP EliteBook 8460p ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.13.0-85-generic root=/dev/mapper/xubuntu--vg-root ro SourcePackage: systemd UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 12/22/2011 dmi.bios.vendor: Hewlett-Packard dmi.bios.version: 68SCF Ver. F.22 dmi.board.name: 161C dmi.board.vendor: Hewlett-Packard dmi.board.version: KBC Version 97.4A dmi.chassis.asset.tag: CZC2033ZHD dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.modalias: dmi:bvnHewlett-Packard:bvr68SCFVer.F.22:bd12/22/2011:svnHewlett-Packard:pnHPEliteBook8460p:pvrA0000C02:rvnHewlett-Packard:rn161C:rvrKBCVersion97.4A:cvnHewlett-Packard:ct10:cvr: dmi.product.name: HP EliteBook 8460p dmi.product.version: A0000C02 dmi.sys.vendor: Hewlett-Packard To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1579336/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp