CIFS kernel module causes kernel crash with kernel-default-6.4.0-150600.23.7.3

This document (000021508) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 15 SP6

Situation

The Linux kernel crashes when mounting a CIFS volume on SUSE Linux Enterprise 15 SP6 running the maintenance update 6.4.0-150600.23.7.3 kernel. Previous kernels are not affected.

Resolution

SUSE engineering is preparing an official maintenance update kernel to fix this issue. It is tentatively expected to release sometime in August 2024, but no exact ETA is promised. In the meantime, there are two options to address this:

1. Mounting the CIFS volume with the "nohandlecache" option should avoid this crash in most cases.

2. A "Mass PTF" kernel, containing a fix, which anyone can download has been made available at:

https://ptf.suse.com/2/f2cf38b50ed714a8409693060195b235/sles15-sp6/28375/x86_64/20240726

(And for more details of applying PTFs, see the "readme.txt" at that link.)

To have access to the PTF server, one must have a SUSE "idp portal" account. This account is used for many things at SUSE, such as Forums, PTFs, and bugzilla. It is separate from the SCC account. More can be learned about this at:

https://idp-portal.suse.com

Cause

A previous fix to the CIFS code has been incompletely back ported to the 6.4.0 kernel.

Status

Reported to Engineering

Disclaimer

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