Activity log for bug #1771620

Date Who What changed Old value New value Message
2018-05-16 16:16:30 aegiap bug added bug
2018-05-16 19:17:20 Joseph Salisbury affects linux-signed (Ubuntu) linux (Ubuntu)
2018-05-16 19:17:20 Joseph Salisbury linux (Ubuntu): importance Undecided Medium
2018-05-16 19:17:27 Joseph Salisbury linux (Ubuntu): status New Triaged
2018-05-16 19:17:34 Joseph Salisbury nominated for series Ubuntu Bionic
2018-05-16 19:17:34 Joseph Salisbury bug task added linux (Ubuntu Bionic)
2018-05-16 19:17:39 Joseph Salisbury linux (Ubuntu Bionic): importance Undecided Medium
2018-05-16 19:17:42 Joseph Salisbury linux (Ubuntu Bionic): status New Triaged
2018-05-16 19:44:42 Joseph Salisbury linux (Ubuntu): assignee Joseph Salisbury (jsalisbury)
2018-05-16 19:44:45 Joseph Salisbury linux (Ubuntu Bionic): assignee Joseph Salisbury (jsalisbury)
2018-05-16 19:44:48 Joseph Salisbury linux (Ubuntu Bionic): status Triaged In Progress
2018-05-16 19:44:50 Joseph Salisbury linux (Ubuntu): status Triaged In Progress
2018-05-18 14:59:35 Joseph Salisbury description On a hosting platform running Xen hypervisor, in a virtual machine with Ubuntu 18.04 system and the default kernel from Ubuntu, I try to detach a virtual network interface. On the Xen side, the virtual interface is removed from the VM but the kernel still has the interface. Then a couple of minutes afterwards, the kernel log show this kernel trace: INFO: task xenwatch:108 blocked for more than 120 seconds. Tainted: G W 4.15.0-20-generic #21-Ubuntu "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. xenwatch D 0 108 2 0x80000000 Call Trace: __schedule+0x297/0x8b0 schedule+0x2c/0x80 xennet_remove+0xda/0x1c0 ? wait_woken+0x80/0x80 xenbus_dev_remove+0x54/0xa0 device_release_driver_internal+0x15b/0x220 device_release_driver+0x12/0x20 bus_remove_device+0xec/0x160 ? xenbus_otherend_changed+0x110/0x110 device_del+0x13d/0x360 ? xenbus_otherend_changed+0x110/0x110 ? xenbus_otherend_changed+0x110/0x110 device_unregister+0x1a/0x60 xenbus_dev_changed+0xa3/0x1e0 ? xenwatch_thread+0xcc/0x160 frontend_changed+0x21/0x50 xenwatch_thread+0xc4/0x160 ? wait_woken+0x80/0x80 kthread+0x121/0x140 ? find_watch+0x40/0x40 ? kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x35/0x40 In the git repository of Linux, the commit c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 (xen-netfront: Fix hang on device removal) https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 seems to be related to this situation. I rebuilded the Ubuntu kernel from the package source and applied this patch. Once the VM has booted with the new kernel, I was able to remove network interface without hangs from the kernel. I also booted the VM with the Ubuntu kernel 4.13.0-42-generic and was able to remove the network interface with success. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-20-generic 4.15.0-20.21 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Uname: Linux 4.15.0-20-generic x86_64 ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 Date: Wed May 16 16:36:06 2018 ProcEnviron: TERM=rxvt-unicode PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: linux-signed UpgradeStatus: No upgrade log present (probably fresh install) == SRU Justification == Upstream commit 5b5971df3bc2 introduced a regression in v4.15-rc2. This regression causes a hang on network interface removal in Xen virtual machine. This regression is fixed by commit c2d2e6738a209 in v4.16-rc4. == Fix == c2d2e6738a20 ("xen-netfront: Fix hang on device removal") == Regression Potential == Low. Fixes a current regression and specific to Xen. == Test Case == A test kernel was built with this patch and tested by the original bug reporter. The bug reporter states the test kernel resolved the bug. On a hosting platform running Xen hypervisor, in a virtual machine with Ubuntu 18.04 system and the default kernel from Ubuntu, I try to detach a virtual network interface. On the Xen side, the virtual interface is removed from the VM but the kernel still has the interface. Then a couple of minutes afterwards, the kernel log show this kernel trace: INFO: task xenwatch:108 blocked for more than 120 seconds.       Tainted: G W 4.15.0-20-generic #21-Ubuntu "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. xenwatch D 0 108 2 0x80000000 Call Trace:  __schedule+0x297/0x8b0  schedule+0x2c/0x80  xennet_remove+0xda/0x1c0  ? wait_woken+0x80/0x80  xenbus_dev_remove+0x54/0xa0  device_release_driver_internal+0x15b/0x220  device_release_driver+0x12/0x20  bus_remove_device+0xec/0x160  ? xenbus_otherend_changed+0x110/0x110  device_del+0x13d/0x360  ? xenbus_otherend_changed+0x110/0x110  ? xenbus_otherend_changed+0x110/0x110  device_unregister+0x1a/0x60  xenbus_dev_changed+0xa3/0x1e0  ? xenwatch_thread+0xcc/0x160  frontend_changed+0x21/0x50  xenwatch_thread+0xc4/0x160  ? wait_woken+0x80/0x80  kthread+0x121/0x140  ? find_watch+0x40/0x40  ? kthread_create_worker_on_cpu+0x70/0x70  ret_from_fork+0x35/0x40 In the git repository of Linux, the commit c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 (xen-netfront: Fix hang on device removal) https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 seems to be related to this situation. I rebuilded the Ubuntu kernel from the package source and applied this patch. Once the VM has booted with the new kernel, I was able to remove network interface without hangs from the kernel. I also booted the VM with the Ubuntu kernel 4.13.0-42-generic and was able to remove the network interface with success. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-20-generic 4.15.0-20.21 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Uname: Linux 4.15.0-20-generic x86_64 ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 Date: Wed May 16 16:36:06 2018 ProcEnviron:  TERM=rxvt-unicode  PATH=(custom, no user)  LANG=en_US.UTF-8  SHELL=/bin/bash SourcePackage: linux-signed UpgradeStatus: No upgrade log present (probably fresh install)
2018-05-23 08:52:03 Stefan Bader linux (Ubuntu Bionic): status In Progress Fix Committed
2018-05-24 18:06:09 Brad Figg tags amd64 apport-bug bionic amd64 apport-bug bionic verification-needed-bionic
2018-05-25 09:53:38 aegiap description == SRU Justification == Upstream commit 5b5971df3bc2 introduced a regression in v4.15-rc2. This regression causes a hang on network interface removal in Xen virtual machine. This regression is fixed by commit c2d2e6738a209 in v4.16-rc4. == Fix == c2d2e6738a20 ("xen-netfront: Fix hang on device removal") == Regression Potential == Low. Fixes a current regression and specific to Xen. == Test Case == A test kernel was built with this patch and tested by the original bug reporter. The bug reporter states the test kernel resolved the bug. On a hosting platform running Xen hypervisor, in a virtual machine with Ubuntu 18.04 system and the default kernel from Ubuntu, I try to detach a virtual network interface. On the Xen side, the virtual interface is removed from the VM but the kernel still has the interface. Then a couple of minutes afterwards, the kernel log show this kernel trace: INFO: task xenwatch:108 blocked for more than 120 seconds.       Tainted: G W 4.15.0-20-generic #21-Ubuntu "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. xenwatch D 0 108 2 0x80000000 Call Trace:  __schedule+0x297/0x8b0  schedule+0x2c/0x80  xennet_remove+0xda/0x1c0  ? wait_woken+0x80/0x80  xenbus_dev_remove+0x54/0xa0  device_release_driver_internal+0x15b/0x220  device_release_driver+0x12/0x20  bus_remove_device+0xec/0x160  ? xenbus_otherend_changed+0x110/0x110  device_del+0x13d/0x360  ? xenbus_otherend_changed+0x110/0x110  ? xenbus_otherend_changed+0x110/0x110  device_unregister+0x1a/0x60  xenbus_dev_changed+0xa3/0x1e0  ? xenwatch_thread+0xcc/0x160  frontend_changed+0x21/0x50  xenwatch_thread+0xc4/0x160  ? wait_woken+0x80/0x80  kthread+0x121/0x140  ? find_watch+0x40/0x40  ? kthread_create_worker_on_cpu+0x70/0x70  ret_from_fork+0x35/0x40 In the git repository of Linux, the commit c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 (xen-netfront: Fix hang on device removal) https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 seems to be related to this situation. I rebuilded the Ubuntu kernel from the package source and applied this patch. Once the VM has booted with the new kernel, I was able to remove network interface without hangs from the kernel. I also booted the VM with the Ubuntu kernel 4.13.0-42-generic and was able to remove the network interface with success. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-20-generic 4.15.0-20.21 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Uname: Linux 4.15.0-20-generic x86_64 ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 Date: Wed May 16 16:36:06 2018 ProcEnviron:  TERM=rxvt-unicode  PATH=(custom, no user)  LANG=en_US.UTF-8  SHELL=/bin/bash SourcePackage: linux-signed UpgradeStatus: No upgrade log present (probably fresh install) == SRU Justification == Upstream commit 5b5971df3bc2 introduced a regression in v4.15-rc2. This regression causes a hang on network interface removal in Xen virtual machine. This regression is fixed by commit c2d2e6738a209 in v4.16-rc4. == Fix == c2d2e6738a20 ("xen-netfront: Fix hang on device removal") == Regression Potential == Low. Fixes a current regression and specific to Xen. == Test Case == A test kernel was built with this patch and tested by the original bug reporter. The bug reporter states the test kernel resolved the bug. On a hosting platform running Xen hypervisor, in a virtual machine with Ubuntu 18.04 system and the default kernel from Ubuntu, I try to detach a virtual network interface. On the Xen side, the virtual interface is removed from the VM but the kernel still has the interface. Then a couple of minutes afterwards, the kernel log show this kernel trace: INFO: task xenwatch:108 blocked for more than 120 seconds.       Tainted: G W 4.15.0-20-generic #21-Ubuntu "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. xenwatch D 0 108 2 0x80000000 Call Trace:  __schedule+0x297/0x8b0  schedule+0x2c/0x80  xennet_remove+0xda/0x1c0  ? wait_woken+0x80/0x80  xenbus_dev_remove+0x54/0xa0  device_release_driver_internal+0x15b/0x220  device_release_driver+0x12/0x20  bus_remove_device+0xec/0x160  ? xenbus_otherend_changed+0x110/0x110  device_del+0x13d/0x360  ? xenbus_otherend_changed+0x110/0x110  ? xenbus_otherend_changed+0x110/0x110  device_unregister+0x1a/0x60  xenbus_dev_changed+0xa3/0x1e0  ? xenwatch_thread+0xcc/0x160  frontend_changed+0x21/0x50  xenwatch_thread+0xc4/0x160  ? wait_woken+0x80/0x80  kthread+0x121/0x140  ? find_watch+0x40/0x40  ? kthread_create_worker_on_cpu+0x70/0x70  ret_from_fork+0x35/0x40 In the git repository of Linux, the commit c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 (xen-netfront: Fix hang on device removal) https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 seems to be related to this situation. I rebuilded the Ubuntu kernel from the package source and applied this patch. Once the VM has booted with the new kernel, I was able to remove network interface without hangs from the kernel. I also booted the VM with the Ubuntu kernel 4.13.0-42-generic and was able to remove the network interface with success. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-20-generic 4.15.0-20.21 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Uname: Linux 4.15.0-20-generic x86_64 ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 Date: Wed May 16 16:36:06 2018 ProcEnviron:  TERM=rxvt-unicode  PATH=(custom, no user)  LANG=en_US.UTF-8  SHELL=/bin/bash SourcePackage: linux-signed UpgradeStatus: No upgrade log present (probably fresh install)
2018-05-25 09:53:38 aegiap tags amd64 apport-bug bionic verification-needed-bionic amd64 apport-bug bionic verification-done-bionic
2018-06-11 15:08:06 Launchpad Janitor linux (Ubuntu Bionic): status Fix Committed Fix Released
2018-06-11 15:08:06 Launchpad Janitor cve linked 2018-1092
2018-06-11 15:08:06 Launchpad Janitor cve linked 2018-3639
2018-06-11 15:08:06 Launchpad Janitor cve linked 2018-8087
2018-06-14 12:16:29 Launchpad Janitor linux (Ubuntu): status In Progress Fix Released