SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server for SAP Applications 15 SP4

Kernel 5.14.21-150400.24.49.3 was installed.  When the system loads this new kernel, NFSv4 client mounts may show question marks where permissions, ownership and other file metadata is expected.  Creating, deleting, and renaming files may not work as expected until the share is unmounted and remounted.

Downgrade to kernel 5.14.21-150400.24.46.1.  Then clean out the old kernel and boot options via zypper and grub.  Steps to accomplish this:

Step 1: Downgrade to the last unaffected kernel:

# zypper in --oldpackage kernel-default-5.14.21-150400.24.46.1

Step 2: Comment out the current multiversion.kernels entry used by zypp.conf:

# sed -i 's/multiversion.kernels/#multiversion.kernels/' /etc/zypp/zypp.conf

Step 3: Append the known working kernel version to the end of the file.  The version set here is matched against the filename in /boot when zypper purge-kernels is called.  The following command actually adds two lines, the first being a comment:

# echo -e "# line below added per TID000021021\nmultiversion.kernels = 5.14.21-150400.24.46" >> /etc/zypp/zypp.conf

Step 4: Purge kernels (which will clean out all but the desired .46 kernel).

# zypper purge-kernels

Step 5: Regenerate GRUB2 configuration:

# grub2-mkconfig -o /boot/grub2/grub.cfg

Step 6: Manually check /boot directory to make sure kernel 5.14.21-150400.24.49 was cleaned up and /boot/grub2/grub.cfg to make sure the bootloader was properly updated with kernel 5.14.21-150400.24.46.

# ls -l /boot
# less /boot/grub2/grub.cfg

Step 7: If everything looks good with step 6, reboot.

# /sbin/reboot

Step 8:  Revert steps #2 and 3, so future kernel releases can once again be installed and booted.

This is safe assuming that the .49 kernel has been removed from your maintenance repositories. That is true for SUSE's public repositories, but for 3rd party repositories, you could check with:

zypper lu | grep kernel-default

You can manually edit /etc/zypp/zypp.conf, remove the 2 lines which step #3 added at the end of the file, and uncomment the original multiversion.kernels earlier in the file; or you can use the following two commands to undo those changes:

# sed -i 's/multiversion.kernels/#multiversion.kernels/' /etc/zypp/zypp.conf
# sed -i 's/##multiversion.kernels/multiversion.kernels/' /etc/zypp/zypp.conf

If you have a problem with any of the above steps, please submit a new case to SUSE support and reference this TID.

Reported to Engineering

Impacted kernel (5.14.21-150400.24.49.3) is listed as retracted on our official kernel list TID here:

https://www.suse.com/support/kb/doc/?id=000019587

The problems with kernel .49 are reported to SUSE Engineering and should be resolved by the next kernel release.

More info can be found in this publicly-accessible bug report logged against openSUSE 15.4.

https://bugzilla.suse.com/show_bug.cgi?id=1209457