Comment 0 for bug 1729337

We have a cluster of servers that applied a security update overnight and were unable to mount CIFS shares after upgrading to 4.4.0-98. The same machines on 4.4.0-97 were fine the night before, and are fine after downgrading. The only error message CIFS would report, even on verbose, was:

[ 257.089876] CIFS VFS: validate protocol negotiate failed: -11
[ 257.089964] CIFS VFS: cifs_mount failed w/return code = -5

Rebooting did not help. Nor did attempting to mount the share manually using mount -t cifs.

Here's the offending line from our /etc/fstab (with hostnames sanitized):

//server/share /mnt/share cifs rw,user,credentials=/etc/samba/credentials.share,uid=33,gid=33,file_mode=0770,dir_mode=0770
,exec,soft,noserverino,vers=3.0 0 0

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-98-generic 4.4.0-98.121
ProcVersionSignature: Ubuntu 4.4.0-98.121-generic 4.4.90
Uname: Linux 4.4.0-98-generic x86_64
AlsaDevices:
 total 0
 crw-rw---- 1 root audio 116, 1 Nov 1 07:56 seq
 crw-rw---- 1 root audio 116, 33 Nov 1 07:56 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
Date: Wed Nov 1 08:49:47 2017
HibernationDevice: RESUME=/dev/mapper/ubuntu--template--vg-swap_1
InstallationDate: Installed on 2016-12-16 (319 days ago)
InstallationMedia: Ubuntu-Server 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lsusb: Error: command ['lsusb'] failed with exit code 1:
MachineType: VMware, Inc. VMware Virtual Platform
PciMultimedia:

ProcFB: 0 svgadrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-98-generic root=/dev/mapper/ubuntu--template--vg-root ro
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-98-generic N/A
 linux-backports-modules-4.4.0-98-generic N/A
 linux-firmware 1.157.13
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/21/2015
dmi.bios.vendor: Phoenix Technologies LTD
dmi.bios.version: 6.00
dmi.board.name: 440BX Desktop Reference Platform
dmi.board.vendor: Intel Corporation
dmi.board.version: None
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 1
dmi.chassis.vendor: No Enclosure
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvr6.00:bd09/21/2015:svnVMware,Inc.:pnVMwareVirtualPlatform:pvrNone:rvnIntelCorporation:rn440BXDesktopReferencePlatform:rvrNone:cvnNoEnclosure:ct1:cvrN/A:
dmi.product.name: VMware Virtual Platform
dmi.product.version: None
dmi.sys.vendor: VMware, Inc.