This bug is missing log files that will aid in diagnosing the problem. >From a terminal window please run:
apport-collect 1555997 and then change the status of the bug to 'Confirmed'. If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'. This change has been made by an automated script, maintained by the Ubuntu Kernel Team. ** Changed in: linux (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1555997 Title: overlay fs regression: chmod fails with "Operation not permitted" on chowned files Status in linux package in Ubuntu: Incomplete Bug description: This is a regression in Xenial's kernel 4.4.0-9 or 4.4.0-10. See comment #3 for simple reproducer. ORIGINAL BUG REPORT =================== I'm investigating some failures in autopkgtest's testsuite, and stumbled over something really weird: In an ephemeral container it is apparently not possible any more to chmod files that started out being root owned and got chowned later: $ sudo lxc-start-ephemeral -o adt-wily (log in as ubuntu/ubuntu) ubuntu@adt-wily-hvzj1eoa:~$ echo hello | sudo tee /tmp/testfile [sudo] password for ubuntu: hello ubuntu@adt-wily-hvzj1eoa:~$ sudo chown ubuntu:ubuntu /tmp/testfile ubuntu@adt-wily-hvzj1eoa:~$ chmod +x /tmp/testfile chmod: changing permissions of ‘/tmp/testfile’: Operation not permitted However, if the file was *not* previously chowned, it works as expected: ubuntu@adt-wily-hvzj1eoa:~$ echo hello > /tmp/testfile2 ubuntu@adt-wily-hvzj1eoa:~$ chmod +x /tmp/testfile2 ubuntu@adt-wily-hvzj1eoa:~$ chmod -x /tmp/testfile2 (no errors and testfile2 becomes executable) There is no visible permission difference in the files at all, other than being group-writable (but changing the group w bit in either direction does not change the error at all): -rw-r--r-- 1 ubuntu ubuntu 6 Mar 11 10:26 /tmp/testfile -rw-rw-r-- 1 ubuntu ubuntu 6 Mar 11 10:26 /tmp/testfile2 ubuntu@adt-wily-hvzj1eoa:~$ stat /tmp/testfile* File: ‘/tmp/testfile’ Size: 6 Blocks: 8 IO Block: 4096 regular file Device: 15h/21d Inode: 28 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 1000/ ubuntu) Gid: ( 1000/ ubuntu) Access: 2016-03-11 10:26:19.574364117 +0100 Modify: 2016-03-11 10:26:19.574364117 +0100 Change: 2016-03-11 10:26:21.930343210 +0100 Birth: - File: ‘/tmp/testfile2’ Size: 6 Blocks: 8 IO Block: 4096 regular file Device: 15h/21d Inode: 29 Links: 1 Access: (0664/-rw-rw-r--) Uid: ( 1000/ ubuntu) Gid: ( 1000/ ubuntu) Access: 2016-03-11 10:26:58.730145919 +0100 Modify: 2016-03-11 10:26:58.730145919 +0100 Change: 2016-03-11 10:27:44.530203985 +0100 Birth: - There are also no ACLs involved (I checked with getfacl). This does not happen with a normal lxc-start, so this might very well be a bug in Linux' overlayfs. However, it also does not happen with the more modern "sudo lxc-copy -n adt-wily --ephemeral --foreground" -- bug perhaps this isn't using overlayfs? ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: lxc 2.0.0~rc9-0ubuntu1 ProcVersionSignature: Ubuntu 4.4.0-11.26-generic 4.4.4 Uname: Linux 4.4.0-11-generic x86_64 ApportVersion: 2.20-0ubuntu3 Architecture: amd64 CurrentDesktop: i3 Date: Fri Mar 11 10:21:20 2016 EcryptfsInUse: Yes PackageArchitecture: all SourcePackage: lxc UpgradeStatus: No upgrade log present (probably fresh install) defaults.conf: lxc.network.type = veth lxc.network.link = lxcbr0 lxc.network.flags = up lxc.network.hwaddr = 00:16:3e:xx:xx:xx dnsmasq.conf: enable-tftp tftp-root=/tmp/tftp dhcp-boot=pxelinux.0 lxc.conf: lxc.lxcpath = /srv/lxc To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1555997/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp