[Bug 2082423] Re: Unable to list directories using CIFS on 6.8 kernel

This bug is awaiting verification that the linux/6.8.0-50.51 kernel in
-proposed solves the problem. Please test the kernel and update this bug
with the results. If the problem is solved, change the tag
'verification-needed-noble-linux' to 'verification-done-noble-linux'. If
the problem still exists, change the tag 'verification-needed-noble-
linux' to 'verification-failed-noble-linux'.


If verification is not done by 5 working days from today, this fix will
be dropped from the source code, and this bug will be closed.


See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how
to enable and use -proposed. Thank you!


** Tags added: kernel-spammed-noble-linux-v2 verification-needed-noble-linux

--
You received this bug notification because you are subscribed to linux
in Ubuntu.
Matching subscriptions: Bgg, Bmail, Nb
https://bugs.launchpad.net/bugs/2082423

Title:
Unable to list directories using CIFS on 6.8 kernel

Status in linux package in Ubuntu:
Fix Released
Status in linux source package in Noble:
Fix Committed

Bug description:
[impact]

Currently on the latest version of the 6.8 kernel, there is an issue where listing directories with CIFS fails and returns an error stating that the operation is not permitted.
There is an upstream patch to fix the issue: https://git.kernel.dk/?p=linux-block.git;a=commitdiff;h=ec686804117a0421cf31d54427768aaf93aa0069
And I have back ported to Noble 6.8. Note that the same issue also affects jammy HWE 6.8.

[Test Plan]

1. Create a CIFS share.
2. Populate the CIFS share directory with files.
3. connect to the CIFS share using a ubuntu noble machine or a jammy machine running 6.8 HWE. Steps to connect to a CIFS share can be found here: https://ubuntu.com/server/docs/how-to-mount-cifs-shares-permanently
4. Once mounted, access the share and try listing the content of the directory with "ls".
5. This will result in the following errors:
ls: cannot access 'file1': Operation not supported
ls: cannot access 'file2': Operation not supported
ls: cannot access 'file3': Operation not supported
ls: cannot access 'file4': Operation not supported

6. Looking at dmesg, the following traces can be seen:
CIFS: VFS: parse_reparse_point: unhandled reparse tag: 0x0000001b
CIFS: fs/smb/client/dir.c: Unexpected lookup error -95

7. The expected output would be to have the files listed wihtout any
"operation not supported" errors or dmesg CIFS related error logs.

[Fix]

The fix is already upstream and is provided by:
* ec686804117a smb: client: ignore unhandled reparse tags

The patch does not apply cleanly due to the following missing commit: c520ba7573a8 smb: client: move most of reparse point handling code to common file
So I had to do a few modifications.

[where problems could occur]
* The patch might not fix the issue and it might still be present in some scenarios.
* Other CIFS commands might break.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2082423/+subscriptions