Adding to the early headaches of Linux 6.19 with some regressions in performance and functionality were ARM64 hosts crashing on this in-development kernel version for those platforms using EFI. But a fix is now merged ahead of Linux 6.19-rc3 due out tomorrow.

It sure would be nice if more ARM64 hosts used EFI, especially in the single board computer (SBC) space but for now it’s a more common trait for ARM64 Linux servers. In any event it turns out ARM64 EFI code was to blame for systems crashing when trying to boot the in-development Linux 6.19 kernel.

ARM64 hosts were hitting a null pointer dereference on boot. It turned out to be an ARM64-specific problem and was tracked down to a change in how ARM64 calls the EFI runtime services on this next version of the kernel. A one line patch was all that ended up being needed so a member of the EFI struct is properly initialized and avoid crashing ARM64 hosts on Linux 6.19.

The patch to fix ARM64 EFI hosts from crashing was merged on Friday and will be found in Sunday’s Linux 6.19-rc3 release.