OP here. I can confirm the reported bug of dfs-referrals had been fixed in 4.4.0-36.55. However, the newer kernel 4.4.0-38.57 has another problem at a more fundamental level: no mount at all.
The fix-reverted version from #39 (4.4.0-38.57+lp1612135v201609211623) re-introduces the original dfs-referrals bug but does allow a mount to occur. Cheers, Chris -- 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/1612135 Title: CIFS client: access problems after updating to kernel 4.4.0-29-generic Status in linux package in Ubuntu: Fix Released Status in linux source package in Xenial: Fix Released Status in linux source package in Yakkety: Fix Released Bug description: SRU Justification Impact: A regression in the xenial kernel causes EPERM to be returned when accessing dfs subfilesystems in a cifs mount. Fix: Upstream cherry pick which uses the appropriate credentials for these automounts. Regression Potential: The fix involves reverting a sauce patch to fix a similar problem in nfs, but it's replace with a more generic fix which fixes cifs as well. I have tested with both nfs and cifs submounts and confirmed that both work as expected. --- Expected: being able to mount subfilesystems via cifs mount. What happens: permission denied even though there is permission I am denied access to the subfilesystems on a samba server. The top level filesystem itself is unaffected but dfs links seem to run into 'Operation not permitted' problems. When accessing the subfilesystem on the mount as root it mounts correctly. The standard user is then also able to access the subfilesystem. This only happens when the client uses kernel 4.4.0-34 (#53). When I revert my client to an older kernel (4.4.0-21) everything works. Using the older kernel the normal user can directly ls into the subfilesystem. This is bug is very similar to bug #1603719 (https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1603719). However, the released fix (in 4.4.0-33.52) does not seem to fix it for cifs. Extra info: Ubuntu 16.04.1 LTS cifs-utils version: 2:6.4-1ubuntu1 Mount options are minimal: sec=krb5,uid=XXXX,cruid=XXX ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: ubuntu-release-upgrader-core 1:16.04.15 ProcVersionSignature: Ubuntu 4.4.0-34.53-generic 4.4.15 Uname: Linux 4.4.0-34-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.1 Architecture: amd64 CrashDB: ubuntu CurrentDesktop: KDE Date: Thu Aug 11 10:32:20 2016 InstallationDate: Installed on 2016-04-28 (104 days ago) InstallationMedia: Kubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1) PackageArchitecture: all ProcEnviron: PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: ubuntu-release-upgrader Symptom: ubuntu-release-upgrader UpgradeStatus: No upgrade log present (probably fresh install) modified.conffile..etc.update-motd.d.91-release-upgrade: [deleted] To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1612135/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : email@example.com Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp