Hello team,

I have updated from RHEL8.4 to RHEL8.8 using dnf update. After rebooting uname -a is showing old kernel(4.18.0-305.25.1.el8_4) whereas /etc/os-release is showing RHE8.8

Also, a strange error while running grub2-mkconfig -o /boot/grub2/grub.cfg:
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.18.0-305.25.1.el8_4.ppc64le
Found initrd image: /boot/initramfs-4.18.0-305.25.1.el8_4.ppc64le.img
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
Found linux image: /boot/vmlinuz-3.10.0-1160.el7.ppc64le
Found initrd image: /boot/initramfs-3.10.0-1160.el7.ppc64le.img
Found linux image: /boot/vmlinuz-upgrade.ppc64le
Found initrd image: /boot/initramfs-upgrade.ppc64le.img
Found linux image: /boot/vmlinuz-0-rescue-3a2fae233b064326be58b8ed2dd76732
Found initrd image: /boot/initramfs-0-rescue-3a2fae233b064326be58b8ed2dd76732.img
Found linux image: /boot/vmlinuz-0-rescue-ccf746c1e2344ee1b5686e118e7adf95
Found initrd image: /boot/initramfs-0-rescue-ccf746c1e2344ee1b5686e118e7adf95.img

done

ls -ltr /boot
total 528864
drwxr-xr-x. 3 root root 17 Nov 18 2021 efi
-rw------- 1 root root 148585 Oct 12 2022 config-4.18.0-305.25.1.el8_4.ppc64le
-rw------- 1 root root 66173185 Oct 12 2022 initramfs-0-rescue-3a2fae233b064326be58b8ed2dd76732.img
drwx------ 3 root root 21 Oct 12 2022 loader
-rw------- 1 root root 3498434 Oct 12 2022 System.map-4.18.0-305.25.1.el8_4.ppc64le
-rwx------ 1 root root 21899560 Oct 12 2022 vmlinuz-0-rescue-3a2fae233b064326be58b8ed2dd76732
-rwx------ 1 root root 29930237 Oct 12 2022 vmlinuz-4.18.0-305.25.1.el8_4.ppc64le
-rw-r--r--. 1 root root 130356 Oct 12 2022 config-3.10.0-1160.el7.ppc64le
-rw-------. 1 root root 66169281 Oct 12 2022 initramfs-0-rescue-ccf746c1e2344ee1b5686e118e7adf95.img
-rw------- 1 root root 22482274 Oct 12 2022 initramfs-3.10.0-1160.el7.ppc64lekdump.img
-rw-r--r--. 1 root root 278628 Oct 12 2022 symvers-3.10.0-1160.el7.ppc64le.gz
-rw------- 1 root root 79098163 Oct 12 2022 initramfs-upgrade.ppc64le.img
-rw-------. 1 root root 3006068 Oct 12 2022 System.map-3.10.0-1160.el7.ppc64le
-rwxr-xr-x. 1 root root 21899560 Oct 12 2022 vmlinuz-0-rescue-ccf746c1e2344ee1b5686e118e7adf95
-rwxr-xr-x. 1 root root 21899560 Oct 12 2022 vmlinuz-3.10.0-1160.el7.ppc64le
-rwxr-xr-x 1 root root 29930237 Oct 12 2022 vmlinuz-upgrade.ppc64le
-rw------- 1 root root 30766978 Oct 12 2022 initramfs-3.10.0-1160.el7.ppc64le.img
-rw------- 1 root root 33121120 Oct 12 2022 initramfs-4.18.0-305.25.1.el8_4.ppc64le.img
-rw------- 1 root root 3687097 Aug 31 2023 System.map-4.18.0-477.27.1.el8_8.ppc64le
-rw-r--r-- 1 root root 152853 Aug 31 2023 config-4.18.0-477.27.1.el8_8.ppc64le
-rwxr-xr-x 1 root root 36030679 Aug 31 2023 vmlinuz-4.18.0-477.27.1.el8_8.ppc64le
-rw------- 1 root root 39775232 Mar 28 15:18 initramfs-4.18.0-305.25.1.el8_4.ppc64lekdump.img
lrwxrwxrwx 1 root root 53 Mar 28 15:21 symvers-4.18.0-477.27.1.el8_8.ppc64le.gz -> /lib/modules/4.18.0-477.27.1.el8_8.ppc64le/symvers.gz
-rw------- 1 root root 31431681 Mar 28 15:21 initramfs-4.18.0-477.27.1.el8_8.ppc64le.img
drwx------. 5 root root 203 Mar 28 15:33 grub2

Quick support would be really appreciated.