Kernal update 5.4.0-81 broke samba network

[Alexius]

Introduction:
I use Samba for linux/windows based network, this involves a shared, ext4 folder on linux mint pc and ntfs drive on router and ntfs folder on windows 7 pc.

thereabouts:
I had all previous updates, that were current before kernal 5.4.0-81, and my network worked fine.
I used the update manager to install kernal 5.4.0-81, from the tray icons (or whatever they are called in linux), as well as updating the relating dependencies when that popped up.
I restarted, and then, I cant, see or acces, the, router storage or windows 7 pc, likewise my windows 7 pc cant, see or access, the linux pc.
I waited a good amount of time, and tried restarting, this didnt work.
I reverted the kernal and dependencies to their earlier version, still same problem, even after several, restarts and waiting.
I notice the modifications to the samba config are still present, that were required for samba to network correctly with, windows pc and router, shares.
I then updated to the new kernal again, because it makes no difference, seems as previous kernal has broken share, therefore, fix will likely be same for both now.

furthermore:
I have asus rt-n65u router with latest firmware.
I am using samba (maybe this, has been affected or needs its code updating?).
the internet is still working, that are a usb dongle through router, to linux mint pc.

----

System: Kernel: 5.4.0-81-generic x86_64 bits: 64 compiler: gcc v: 9.3.0 Desktop: Cinnamon 5.0.5
           wm: muffin dm: LightDM Distro: Linux Mint 20.2 Uma base: Ubuntu 20.04 focal
Machine: Type: Desktop Mobo: MSI model: FM2-A55M-P33 (MS-7721) v: 3.0 serial: <filter>
           UEFI: American Megatrends v: 11.6 date: 02/12/2015
CPU: Topology: Quad Core model: AMD A10-6700 APU with Radeon HD Graphics bits: 64 type: MCP
           arch: Piledriver rev: 1 L2 cache: 2048 KiB
           flags: avx lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm bogomips: 29546
           Speed: 2350 MHz min/max: 1800/3700 MHz Core speeds (MHz): 1: 2321 2: 2310 3: 2207
           4: 2156
Graphics: Device-1: AMD Pitcairn PRO [Radeon HD 7850 / R7 265 / R9 270 1024SP]
           vendor: PC Partner Limited driver: radeon v: kernel bus ID: 01:00.0 chip ID: 1002:6819
           Display: x11 server: X.Org 1.20.11 driver: ati,radeon unloaded: fbdev,modesetting,vesa
           resolution: 1920x1080~60Hz
           OpenGL: renderer: AMD PITCAIRN (DRM 2.50.0 5.4.0-81-generic LLVM 12.0.1)
           v: 4.5 Mesa 21.3.0-devel (git-513fb54 2021-08-12 focal-oibaf-ppa) direct render: Yes
Audio: Device-1: AMD FCH Azalia vendor: Micro-Star MSI driver: snd_hda_intel v: kernel
           bus ID: 00:14.2 chip ID: 1022:780d
           Device-2: AMD Oland/Hainan/Cape Verde/Pitcairn HDMI Audio [Radeon HD 7000 Series]
           vendor: PC Partner Limited driver: snd_hda_intel v: kernel bus ID: 01:00.1
           chip ID: 1002:aab0
           Device-3: Generalplus USB Audio Device type: USB
           driver: hid-generic,snd-usb-audio,usbhid bus ID: 7-2:2 chip ID: 1b3f:2008
           Sound Server: ALSA v: k5.4.0-81-generic
Network: Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet vendor: Micro-Star MSI
           driver: r8169 v: kernel port: d000 bus ID: 02:00.0 chip ID: 10ec:8168
           IF: enp2s0 state: up speed: 1000 Mbps duplex: full mac: <filter>
Drives: Local Storage: total: 380.08 GiB used: 86.82 GiB (22.8%)
           ID-1: /dev/sda type: USB vendor: Micron model: MT-32 VLI size: 29.82 GiB
           speed: 3.0 Gb/s serial: <filter>
           ID-2: /dev/sdb model: BT58SSD10S size: 238.47 GiB speed: 3.0 Gb/s serial: <filter>
           temp: 40 C
           ID-3: /dev/sdc vendor: SanDisk model: SDSSDHII120G size: 111.79 GiB speed: 3.0 Gb/s
           serial: <filter> temp: 30 C
Partition: ID-1: / size: 233.24 GiB used: 78.37 GiB (33.6%) fs: ext4 dev: /dev/sdb2
           ID-2: swap-1 size: 55.89 GiB used: 0 KiB (0.0%) fs: swap dev: /dev/sdc1
Sensors: System Temperatures: cpu: 20.5 C mobo: N/A gpu: radeon temp: 36 C
           Fan Speeds (RPM): N/A
Repos: No active apt repos in: /etc/apt/sources.list
           Active apt repos in: /etc/apt/sources.list.d/additional-repositories.list
           1: deb https: //dl.winehq.org/wine-builds/ubuntu/ bionic main
           Active apt repos in: /etc/apt/sources.list.d/cybermax-dexter-sdl2-backport-focal.list
           1: deb http: //ppa.launchpad.net/cybermax-dexter/sdl2-backport/ubuntu focal main
           Active apt repos in: /etc/apt/sources.list.d/official-package-repositories.list
           1: deb https: //www.mirrorservice.org/sites/packages.linuxmint.com/packages uma main upstream import backport
           2: deb http: //mirror.as29550.net/archive.ubuntu.com focal main restricted universe multiverse
           3: deb http: //mirror.as29550.net/archive.ubuntu.com focal-updates main restricted universe multiverse
           4: deb http: //mirror.as29550.net/archive.ubuntu.com focal-backports main restricted universe multiverse
           5: deb http: //security.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse
           6: deb http: //archive.canonical.com/ubuntu/ focal partner
           Active apt repos in: /etc/apt/sources.list.d/oibaf-graphics-drivers-focal.list
           1: deb http: //ppa.launchpad.net/oibaf/graphics-drivers/ubuntu focal main
Info: Processes: 221 Uptime: 48m Memory: 15.66 GiB used: 2.12 GiB (13.5%) Init: systemd
           v: 245 runlevel: 5 Compilers: gcc: 9.3.0 alt: 9 Client: Unknown python3.8 client
           inxi: 3.0.38

[Tim Gardner (timg-tpi)]

Alexius - there were a number of cifs patches in 5.40.81:

git log --pretty=oneline Ubuntu-5.4.0-80.90..Ubuntu-5.4.0-81.91 -- fs/cifs
75b60ff911d81192c6bd460c80fb59126d068d5a cifs: handle empty list of targets in cifs_reconnect()
23c1f856df591edab3ae8af9008fe20ec46c673e cifs: get rid of unused parameter in reconn_setup_dfs_targets()
55811c48507f528d1ecaf1717e06208edbead552 cifs: On cifs_reconnect, resolve the hostname again.
37a4049bdd389dbdeda8cb984260214fa82c86b7 cifs: Avoid error pointer dereference
651f03d7c1f4644d6eb8392f2aa20a77a5f3ee18 cifs: Simplify reconnect code when dfs upcall is enabled
b7c09698a489f05bf7dcf6adad2e7d3c20ac8aa2 cifs: rename reconn_inval_dfs_target()

Please try the kernel in this PPA to see if reverting those patches fixes your problem:

https://launchpad.net/~timg-tpi/+archive/ubuntu/cifs-revert-cifs-lp1939845

[Alexius (wise-time)]

Solved.

I reinstalled the whole system exactly the same, then created a timeslide this time, to then update the kernal..and network was, fine and working as expected.

The previous install was a fresh install, I had just started using the linux mint firewall,in the same session, before installing the kernal update.

The issue was with the firewall that comes with linux mint, when booted with firewall on, it did not allow network shares to operate correctly, thereabouts:

-the firewall to linux mint is by default off (which is obviously a bad idea as some users wont find it till later, and may assume its already on).
-the built in firewall to linux mint does not have a "learning/training mode", which is a essential feature in my mind, to have prompts on new internet access by apps.
-after booting with firewall on, then turning the firewall off, then the network shares do still not work, obviously samba needs some rule creation for firewall to be on (looking into this).

Thus, I do apologise, im a new user to linux, but, the issue was not with the kernal, its with the firewall that ships with linux mint, or the samba not automatically/prompting creating firewall rules.

[Alexius (wise-time)]

Thanks for assistance Tim Gardner (timg-tpi)

[Alexius (wise-time)]

FYI

Adding the preconfigured firewall rule for samba, direction both, category all, subcategory all, does not allow network to work correctly, even after rebooting with the firewall on. this is surely an issue.

[Tim Gardner (timg-tpi)]

Marking this bug invalid since it does not appear to be a kernel issue.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1939845

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]