If the issue of 2211784 – fedora 38 kernel 6.3.4 boot fail upon upgrade applies to you and if you want to test the kernel that Justin provided, you can install that one by
sudo dnf update https://kojipkgs.fedoraproject.org//work/tasks/3237/101713237/kernel-6.3.5-201.fc38.x86_64.rpm https://kojipkgs.fedoraproject.org//work/tasks/3237/101713237/kernel-core-6.3.5-201.fc38.x86_64.rpm https://kojipkgs.fedoraproject.org//work/tasks/3237/101713237/kernel-modules-6.3.5-201.fc38.x86_64.rpm https://kojipkgs.fedoraproject.org//work/tasks/3237/101713237/kernel-modules-core-6.3.5-201.fc38.x86_64.rpm https://kojipkgs.fedoraproject.org//work/tasks/3237/101713237/kernel-modules-extra-6.3.5-201.fc38.x86_64.rpm
→ these are from https://koji.fedoraproject.org/koji/taskinfo?taskID=101713237 , which is the descendant of https://koji.fedoraproject.org/koji/taskinfo?taskID=101713227
Be aware: This kernel is only for x86_64. dnf will check if the packages fit your system. This should look like a normal kernel update: dnf downloads the packages, shows you what it will install and what it removes, then you can chose Y/N and then it installs. Do not skip any errors or warnings! If any come up, let us know here.
Please check in advance that another kernel that works remains installed! E.g., if the last kernel that works for you is 6.2.15., check if dnf will remove 6.2.15 before chosing Y (this can happen if you have deployed already earlier 6.3.X kernels or so). By default, Fedora keeps only the most recent 3 kernels. If that issue happens, I suggest to change (in advance to the dnf command) the option installonly_limit=3 to installonly_limit=4 in /etc/dnf/dnf.conf, which increases the number of kernels that remain installed to 4.
Also, it can happen on your systems that dnf does not install all packages that I have put in the dnf command. If dnf chooses itself to ignore some, this is ok. You can proceed as long as no warnings/errors come up.
Also, be aware that this kernel is experimental. This is why it should be used for testing the bug fix only. Once some people confirmed that it works, the fix will be pushed through the whole testing processes of Fedora until it ends up in one of the next kernels to be deployed in “production”.