accessing cifs DFS mount fails after updating to 5.4.0-71-generic

[Kjell Braden]

On focal, after updating to 5.4.0-71-generic kernel and modules, I cannot access a CIFS DFS share anymore.

# mount -t cifs -o iocharset=utf8,user=username,dom=domain '\\winfs.redacted.corp\WINFS' /mnt
# ls -l /mnt/dir/DFS_SHARE/subdir
ls: cannot access '/mnt/dir/DFS_SHARE/subdir': No such file or directory

The same process reliably works on 5.4.0-70-generic.

[Matthew Ruffell (mruffell)]

Hi Kjell,

Thanks for reporting the issue! We have been tracking it in bug 1923670.

We found the root cause, and we have commit a fix to the source code tree. This will be fixed in the next kernel update hopefully.

Thanks,
Matthew