** Description changed: + [Impact] + + * In NTP 4.2.8p4 there are several races that can cause a crash on + startup or on a bit later but still on startup by DNS querying a + peer. + + * The crash obviously affects users, especially as it seems - due to + its racy nature - not appear on most, but severely hamstring some + other users. + + * The details are a bit blurred, but overall there were four fixes + upstream that address just this "kind of issue" that seemed to + surface post 4.2.8p4. + + [Test Case] + + * Start NTP (service) + + * Expectation: work + + * Failure: Crash + + * Constraints: this is a race, it seems to appear at <0.1% chance to + all systems I have (or lower - as I just can say it didn't trigger in + 1000 tests). But that matches other reports. OTOH for some systems it + seems to trigger >50% which also matches the high amount of crash + reports (close to 20k now) as referred in comment 43 + + [Regression Potential] + + * Eventually the change is rather invasive as it changes the locking + scheme of parts of the code - so there surely is some regression + potential. + + * Fortunately not all, but most of this change is upstream and tested + quite heavily a few months already. + + * I tested as good as I could and could neither in code nor in test + find an obvious weakness, and looking at all the crash reports it is + about time. + + [Other Info] + + * While all study of bugs, upstream changes and tests suggest we + haven't broken anything, still I have to admit that "on my own" I + can't confirm that it fixed the bug. So we are really dependent on + the reporters here that seem to have the kind of hardware where it + "crashes reliably". + + + -------- + + ntp crashes every time the network goes up or down while the system is running and also crashes after booting up without network. - --- + --- ApportVersion: 2.20.1-0ubuntu1 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-03-12 (26 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160224) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu4 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-17-generic root=UUID=306314bc-efcb-4c2d-b0e9-e05ec92ed0f0 ro ProcVersionSignature: Ubuntu 4.4.0-17.33-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-17-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True - --- + --- ApportVersion: 2.20.1-0ubuntu1 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-03-12 (31 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160224) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-18-generic root=UUID=306314bc-efcb-4c2d-b0e9-e05ec92ed0f0 ro ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-18-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True - --- + --- ApportVersion: 2.20.1-0ubuntu1 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-13 (0 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160412) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-18-generic root=UUID=13f57794-2e19-4a56-836a-94185bba5ec5 ro quiet splash ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-18-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True - --- + --- ApportVersion: 2.20.1-0ubuntu1 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-13 (0 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160412) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-18-generic root=UUID=13f57794-2e19-4a56-836a-94185bba5ec5 ro quiet splash ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-18-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True - --- + --- ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-14 (3 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160412) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-20-generic root=UUID=b9c0528f-e81f-4b08-9b31-032f14f72ccd ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 4.4.0-20.36-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-20-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True - --- + --- ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-14 (3 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160412) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-20-generic root=UUID=b9c0528f-e81f-4b08-9b31-032f14f72ccd ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 4.4.0-20.36-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-20-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True - --- + --- ApportVersion: 2.20.1-0ubuntu2.1 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-14 (63 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160412) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-25-generic root=UUID=3aea4570-4011-4247-9636-68317385324d ro ProcVersionSignature: Ubuntu 4.4.0-25.44-generic 4.4.13 Tags: xenial third-party-packages Uname: Linux 4.4.0-25-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dialout dip lpadmin mail netdev plugdev sambashare sudo _MarkForUpload: True
** Changed in: ntp (Ubuntu Xenial) Status: Confirmed => Fix Committed ** Patch added: "debdiff for Xenial SRU - v1" https://bugs.launchpad.net/ubuntu/+source/ntp/+bug/1567540/+attachment/4711503/+files/SRU-fix-ntp-1567540.debdiff -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ntp in Ubuntu. https://bugs.launchpad.net/bugs/1567540 Title: ntpd crashed with SIGABRT (was: ntp crashes everytime the network goes up or down.) Status in NTP: Fix Released Status in ntp package in Ubuntu: Fix Released Status in ntp source package in Xenial: Fix Committed Bug description: [Impact] * In NTP 4.2.8p4 there are several races that can cause a crash on startup or on a bit later but still on startup by DNS querying a peer. * The crash obviously affects users, especially as it seems - due to its racy nature - not appear on most, but severely hamstring some other users. * The details are a bit blurred, but overall there were four fixes upstream that address just this "kind of issue" that seemed to surface post 4.2.8p4. [Test Case] * Start NTP (service) * Expectation: work * Failure: Crash * Constraints: this is a race, it seems to appear at <0.1% chance to all systems I have (or lower - as I just can say it didn't trigger in 1000 tests). But that matches other reports. OTOH for some systems it seems to trigger >50% which also matches the high amount of crash reports (close to 20k now) as referred in comment 43 [Regression Potential] * Eventually the change is rather invasive as it changes the locking scheme of parts of the code - so there surely is some regression potential. * Fortunately not all, but most of this change is upstream and tested quite heavily a few months already. * I tested as good as I could and could neither in code nor in test find an obvious weakness, and looking at all the crash reports it is about time. [Other Info] * While all study of bugs, upstream changes and tests suggest we haven't broken anything, still I have to admit that "on my own" I can't confirm that it fixed the bug. So we are really dependent on the reporters here that seem to have the kind of hardware where it "crashes reliably". -------- ntp crashes every time the network goes up or down while the system is running and also crashes after booting up without network. --- ApportVersion: 2.20.1-0ubuntu1 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-03-12 (26 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160224) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu4 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-17-generic root=UUID=306314bc-efcb-4c2d-b0e9-e05ec92ed0f0 ro ProcVersionSignature: Ubuntu 4.4.0-17.33-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-17-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True --- ApportVersion: 2.20.1-0ubuntu1 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-03-12 (31 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160224) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-18-generic root=UUID=306314bc-efcb-4c2d-b0e9-e05ec92ed0f0 ro ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-18-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True --- ApportVersion: 2.20.1-0ubuntu1 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-13 (0 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160412) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-18-generic root=UUID=13f57794-2e19-4a56-836a-94185bba5ec5 ro quiet splash ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-18-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True --- ApportVersion: 2.20.1-0ubuntu1 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-13 (0 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160412) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-18-generic root=UUID=13f57794-2e19-4a56-836a-94185bba5ec5 ro quiet splash ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-18-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True --- ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-14 (3 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160412) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-20-generic root=UUID=b9c0528f-e81f-4b08-9b31-032f14f72ccd ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 4.4.0-20.36-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-20-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True --- ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-14 (3 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160412) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-20-generic root=UUID=b9c0528f-e81f-4b08-9b31-032f14f72ccd ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 4.4.0-20.36-generic 4.4.6 Tags: xenial Uname: Linux 4.4.0-20-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True --- ApportVersion: 2.20.1-0ubuntu2.1 Architecture: amd64 CurrentDesktop: XFCE DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-14 (63 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160412) NtpStatus: ntpq: read: Connection refused Package: ntp 1:4.2.8p4+dfsg-3ubuntu5 PackageArchitecture: amd64 ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-25-generic root=UUID=3aea4570-4011-4247-9636-68317385324d ro ProcVersionSignature: Ubuntu 4.4.0-25.44-generic 4.4.13 Tags: xenial third-party-packages Uname: Linux 4.4.0-25-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dialout dip lpadmin mail netdev plugdev sambashare sudo _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/ntp/+bug/1567540/+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