Raspberry Pi4B / (64bit 21.04): 5.11 kernel tree's -1014-raspi / 1015-raspi apt update kills the OS
Ubuntu boots from fat32 partition of sd-card. During flashing the new kernel, the old one's files are saved with .bak extension. So, just rename them using another Linux.
- Mount your boot partition (
/dev/sda1in my case)
sudo mount /dev/sda1 /mnt
- Rename all files with
.baksuffix.
sudo rename -f -v 's/.bak//g' /mnt/*.bak
sudo rename -f -v 's/.bak//g' /mnt/overlays/*.bak
Done!
UPD: If the reason for your issue is too small boot partition this approach may not helps you.