** Description changed: + [Impact] + + Disconnecting a thunderbolt docking station on a Dell Inc. XPS 13 + 9360/0D4J15 can cause a general protection fault (with kernel 5.3.0-40 + and above). + + The bug has been introduced by this upstream commit: + + ffe3bcaf02c4 ptp: fix the race between the release of ptp_clock and + cdev + + Reverting the commit is not a viable option, because we would re- + introduce another bug. + + The fix is to do something similar to this: + + 75718584cb3c64e6269109d4d54f888ac5a5fd15 "ptp: free ptp device pin + descriptors properly" + + and call posix_clock_unregister() in ptp_clock_release(). NOTE: this bug + is also present upstream! + + In addition to that it seems that we can also trigger a kernel oops with + the igb driver if this additional upstream fix is not applied: + + 94bc1e522b32c866d85b5af0ede55026b585ae73 ("igb/igc: Don't warn on + fatal read failures when the device is removed") + + [Test case] + + Bug reported provided the test case by physically disconnecting the + docking station. The problems can be easily reproduced. + + [Fix] + + Apply upstream commit: + + 94bc1e522b32c866d85b5af0ede55026b585ae73 ("igb/igc: Don't warn on + fatal read failures when the device is removed") + + And a custom patch to call call posix_clock_unregister() from + ptp_clock_release(). + + [Regression potential] + + About the upstream commit the regression potential is minimal. The other + custom fix seems to be pretty straightforward. We may consider to post + this upstream and wait for a better feedback from the community. + + [Original report] + happens each time on kernel 5.3.0-40 when I disconnect thunderbolt docking station. Does *not* happen on 5.3.0-28. After it happens almost everything still works ok: the only malfunction I've noticed is that after reconnecting the dock, USB devices (mouse, keyboard) connected via the dock don't work at all. However monitor connected via the dock still works fine. Hardware essentials: Dell Inc. XPS 13 9360/0D4J15, BIOS 2.13.0 Plugable TBT3-UDV Docking Station Does not happen when disconnecting "simpler" devices like apple's usb-c to hdmi/usb/usb-c adapter. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-5.3.0-40-generic 5.3.0-40.32~18.04.1 ProcVersionSignature: Ubuntu 5.3.0-40.32~18.04.1-generic 5.3.18 Uname: Linux 5.3.0-40-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.11 Architecture: amd64 Date: Wed Feb 26 05:23:00 2020 InstallationDate: Installed on 2020-01-01 (55 days ago) InstallationMedia: Ubuntu-MATE 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805) ProcEnviron: - LANGUAGE=en_IE:en - TERM=xterm - PATH=(custom, no user) - LANG=en_IE.UTF-8 - SHELL=/bin/bash + LANGUAGE=en_IE:en + TERM=xterm + PATH=(custom, no user) + LANG=en_IE.UTF-8 + SHELL=/bin/bash SourcePackage: linux-signed-hwe UpgradeStatus: No upgrade log present (probably fresh install)
** Changed in: linux-signed-hwe (Ubuntu Bionic) Importance: Undecided => High ** Changed in: linux-signed-hwe (Ubuntu Bionic) Assignee: (unassigned) => Andrea Righi (arighi) ** Also affects: linux-signed-hwe (Ubuntu Focal) Importance: Medium Assignee: Andrea Righi (arighi) Status: New ** Changed in: linux-signed-hwe (Ubuntu Focal) Importance: Medium => High -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1864754 Title: Kernel Oops - general protection fault: 0000 [#1] SMP PTI after disconnecting thunderbolt docking station To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe/+bug/1864754/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs