Arch Linux

Please read this before reporting a bug:

Do NOT report bugs when a package is just outdated, or it is in the AUR. Use the 'flag out of date' link on the package page, or the Mailing List.

REPEAT: Do NOT report bugs for outdated packages!

FS#71823 - [linux] general protection fault in cifs

Attached to Project: Arch Linux
Opened by Arne Hoch (derhoch) - Friday, 13 August 2021, 07:58 GMT
Last edited by Andreas Radke (AndyRTR) - Tuesday, 31 August 2021, 18:02 GMT
Task Type Bug Report
Category Kernel
Status Assigned
Assigned To Jan Alexander Steffens (heftig)
Architecture x86_64
Severity High
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 0%
Votes 0
Private No


I have a cifs mount via OpenVPN, that is sometimes a bit unstable. After upgrading from linux-5.12.14 to linux-5.13.9, I regularly get general protection faults that leave an unresponsive system. Even magic sysrq isn't able to reboot.

A downgrade to linux-5.12.14 solves the issue.

Additional info:
I've attached the kernel log until the system dies. The ip address of the network share is replaced with '****'
This task depends upon

Comment by Arne Hoch (derhoch) - Monday, 16 August 2021, 09:13 GMT
The problem persists with linux-5.13.10. I have an OpenVPN link open and as soon as I mount the share via tun0 device, I get a load of backtraces and the system halts. But if I add "vers=1.0" to the mount options, the system is stable, so far.
Mounting local network shares is no problem. So it seems to be a combination of vpn and cifs.
Comment by Arne Hoch (derhoch) - Wednesday, 18 August 2021, 15:08 GMT
I think I got to the bottom of this issue. I use a systemd.mount and systemd.automount unit to mount the network share. In the .mount unit I had TimeoutSec=500ms. Due to the latency of the vpn tunnel, the timeout was too short to complete the mount. It seems that linux-5.13 needs more time than linux-5.12 to complete the mount and when the mount command is killed at exactly the right time, I get a nice kernel panic.