[readded 1113942@bugs.debian.org to Cc:] Hello Philipp, On Mon, Sep 15, 2025 at 02:42:59PM +0200, Philipp Klaus Krause wrote: > > Can you please bisect the problem using the kernel packages available at > > https://snapshot.debian.org/package/linux/ to find the first affected > > version? > > (That is, pick a version between 6.12.38 (current newest good) and > > 6.16.3 (current oldest bad) and test that. Depending on the outcome > > update your notion of "current newest good" or "current oldest bad" and > > repeat until you find two consecutive packages where one is good and the > > other is bad. If that sketch of the procedure is too sparse for you to > > follow, please ask for more details.) > > > > The likely outcome is that the first broken version is the first package > > for a new major release. In that case the followup is likely to continue > > bisecting using git on the mainline history. Instructions will follow > > then. > > > > In the end make sure to uninstall all the old kernel versions again. > > This might also be necessary in the middle of the bisection process if > > space in /boot runs out. > > Is there some howto for that? It has been more than a decade since I > compiled a Linux kernel. Another bug where I provided such a howto is #1109203, you can take a look there if you want to know already now. You can also start with that procedure without testing images at all. The cost is probably ~5 or so more steps (involving a kernel compilation, so it takes some time), but then you don't have to go through the hassle to check authenticity of the packages from snapshot.d.o (or configure apt to do it for you). > How can I try those kernels from the link you provided? There is a generic description at https://snapshot.debian.org/. A slightly easier (but formally unsafe) option is to just download the packages and install them using dpkg. > Installing the .deb packages and choosing the kernels in the grub boot menu > gets me an error message "Fehler: Falsche Shim-Signatur". Do I need to > disable Secure Boot? Will disabling Secure boot or switching it on again > later require a reinstallation of Debian? You don't need to disable Secure Boot, but doing that will simplify things. I'm pretty sure you don't need to reinstall when switching, but I'm unsure if it involves some bootloader fiddling. With Secure Boot enabled you have to pick the test images from https://snapshot.debian.org/package/linux-signed-amd64/. For booting self-compiled images during the git bisection process later you have to use your own signing key, see https://wiki.debian.org/SecureBoot#MOK_-_Machine_Owner_Key for the details. Best regards Uwe
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