cifs share sometimes stops working while saving file

[Kristaps Dinvietis]

I have mounted cifs share using /etc/fstab
//CIFS/share /mnt/test cifs cred=/some/credfile,uid=user,gid=user,file_mode=0775,dir_mode=0775 0 0
destination server is NetApp Release 9.1P10
when saving file, for example "unzip /home/user/some.zip -d /mnt/test/2018/", sometimes it ends with error:
Archive: /home/user/some.zip
  inflating: /mnt/test/2018/some.xml fchmod (file attributes) error: Permission denied
 (warning) cannot set modif./access times
          Permission denied

This happens approximately once in 20 saves for file sized about 100MB. After this error cifs share is not usable until remounted, and then it will work till next error.
errors from /var/log/kernel.log :
Oct 19 17:46:00 hostname kernel: [23873.602848] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:00 hostname kernel: [23873.603404] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:00 hostname kernel: [23873.605292] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:00 hostname kernel: [23873.605790] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:00 hostname kernel: [23873.606299] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:00 hostname kernel: [23873.606766] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:00 hostname kernel: [23873.607260] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:00 hostname kernel: [23873.611361] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:00 hostname kernel: [23873.612067] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:00 hostname kernel: [23873.612576] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:07 hostname kernel: [23879.954620] cifs_vfs_err: 1341 callbacks suppressed
Oct 19 17:46:07 hostname kernel: [23879.954625] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:07 hostname kernel: [23879.955642] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:17 hostname kernel: [23890.370511] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:17 hostname kernel: [23890.371491] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:17 hostname kernel: [23890.388960] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:17 hostname kernel: [23890.389950] CIFS VFS: SMB signature verification returned error = -13
Oct 19 17:46:17 hostname kernel: [23890.390467] CIFS VFS: cifs_put_smb_ses: Session Logoff failure rc=-13

entry from /etc/mtab :
//CIFS/share /mnt/test cifs rw,relatime,vers=1.0,cache=strict,username=username,domain=DOMAIN,uid=1000,forceuid,gid=1000,forcegid,addr=192.168.77.77,file_mode=0775,dir_mode=0775,nounix,mapposix,rsize=61440,wsize=65471,echo_interval=60,actimeo=1 0 0

And when share is mounted there is one error/warning? in /var/log/kernel.log , but setting noserverino wont help:
Oct 19 17:45:25 hostname kernel: [23838.095951] CIFS VFS: Autodisabling the use of server inode numbers on \\CIFS\share. This server doesn't seem to support them properly. Hardlinks will not be recognized on this mount. Consider mounting with the "noserverino" option to silence this message.

What seems to help is setting manually vers=3.0 in /etc/fstab, but then there is the same error about signature verification when unmounting, that is why i am not so sure it helps, maybe it only happens less frequently.

Kristaps.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: cifs-utils 2:6.4-1ubuntu1.1
ProcVersionSignature: Ubuntu 4.4.0-137.163-generic 4.4.144
Uname: Linux 4.4.0-137-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
Date: Fri Oct 19 18:20:25 2018
InstallationDate: Installed on 2016-04-26 (905 days ago)
InstallationMedia: Ubuntu-Server 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.3)
ProcEnviron:
 LANGUAGE=en_US:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: cifs-utils
UpgradeStatus: No upgrade log present (probably fresh install)