This is a kernel bug, introduced by one of these patches applied to xenial:
commit d823dfc03906fd278ae6f48219c4ed53faee6f9d Author: Al Viro <[email protected]> Date: Thu Jun 27 20:16:00 2019 +0200 bio_copy_from_iter(): get rid of copying iov_iter commit aceb27a7de5fc65a3fc70ccac344f33099e8a4dc Author: Keith Busch <[email protected]> Date: Thu Jun 27 20:16:00 2019 +0200 block: Clear kernel memory before copying to user commit a713ff5b13e8fd9e331fd84232806316aa9e9b2a Author: Keith Busch <[email protected]> Date: Thu Jun 27 20:16:00 2019 +0200 block/bio: Do not zero user pages -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1837235 Title: systemd 229-4ubuntu21.22 ADT test failure with linux 4.4.0-156.183 (storage) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1837235/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
